![suffered devastating floods whilst Delhi experienced a major
draught. The people of Ethiopia are facing starvation in their
millions because of the year-by-year failure of the rains.
● Insurance companies are good barometers of change. One of the
largest, Munich Re, states that claims due to storms have doubled
in every decade since 1960. In that decade there were 16 disasters
costing £30 billion. In the last decade of the century there were 70
disasters costing £250 billion. In the first years of this century the
pace has quickened. Munich Re has reported that the 700 natural
disasters in 2003 claimed 50 000 lives and cost the insurers £33 billion.
The Loss Prevention Council has stated that, by the middle of this
century, losses will be ‘unimaginable’. Yet, these extreme climatic
events are only part of the scenario of global warming.
● Besides the effect of increasingly steep pressure gradients another
factor contributing to the intensification of storms is the contraction
of snow fields. These have in the past created high pressure zones
of cold stable air which have kept at bay the Atlantic lows with their
attendant storms. This barrier has weakened and shifted further
east allowing the storms to reach western Europe. The increased
frequency of storms and floods in this area during the last decade of
the twentieth century adds weight to this conclusion.
● El Niño has produced unprecedentedly severe effects due to the
warming of the Pacific. There is even talk that the El Niño reversal
may become a fixture which would have dire consequences for
Australia and Southeast Asia.
● Receding polar ice is resulting in the rapid expansion of flora;
Antarctic summers have lengthened by up to 50 per cent since the
1970s and new species of plants have appeared as glaciers have
retreated. In Iceland Europe’s largest glacier is breaking up and is
likely to slide into the north Atlantic within the next few years, high-
lighting the threat to sea levels from land-based ice (The Observer,
22 October 2000). The Arctic ice sheet has thinned by 40 per cent
due to global warming (report by an international panel of climate
scientists, January 2001).
● Sea level has risen 250 mm (10 inches) since 1860. Up to now much
of the sea level rise has been due to thermal expansion.
● Sea temperatures in Antarctica are rising at five times the global
average, at present a 2.5C increase since the 1940s. The major
threat lies with the potential break-up of land-based ice. The recent
breakaway of the 12 000 sq. km of the Larson B ice shelf has serious
implications. In itself it will not contribute to rising sea levels. The
danger lies in the fact that the ice shelves act as a bulwark support-
ing the land-based ice. In the May 2003 edition of Scientific
American it was reported that, following the collapse of the Larson
ice shelf ‘inland [land based] glaciers have surged dramatically
towards the coast in recent years’. Satellite measurements have
shown that the two main glaciers have advanced 1.25 and 1.65 km
ARCHITECTURE IN A CLIMATE OF CHANGE
8](https://image.slidesharecdn.com/561979-250521125847-be8ad6c9/85/Architecture-In-A-Climate-Of-Change-2nd-Edition-Peter-F-Smith-29-320.jpg)
![12
Chapter
Two
Predictions
There is considerable scientific research effort being targeted on the
likely consequences of climate change particularly within the scenario
that the industrialised nations will continue indefinitely with ‘busi-
ness as usual’ (BaU). This BaU scenario assumes some changes and
improvements in efficiency in technology. Here are some of the
predictions.
● Historic sea levels are well recorded in the Bahamas and Bermuda
because these islands have not been subject to tectonic rise and
fall. Ancient shorelines show that, at its extreme, sea level was 20 m
(70 ft) above the present level during an interglacial period 400 000
years ago. This would occur if all the world’s vast ice sheets disinte-
grated. There is a serious risk of this happening to the West
Antarctic and Greenland ice sheets and their loss would mean a
12 m rise in sea level (Geology, vol. 27, p. 375).
● In 2001 Antarctic scientists indicated that sea levels could rise by
6 m (20 ft) within 25 years (Reuters). Ultimately, ‘when Antarctica
melts it [sea level] will be another 110 metres’ (Sir David King, The
Guardian, 14 July 2004).
● Many millions of people live below one metre above sea level. For
example, Singapore and its reclaimed territories will be at risk if the
sea level rises above 20 cm. The Thames barrage is already
deemed to be inadequate. Hamburg is 120 kilometres from the sea
but could be inundated. The mean high tidal water level has
increased between 40 and 50 cm since the 1970s.
● The condition of the Greenland ice cap is another cause for con-
cern. According to one scenario ‘warming of less than 3C – likely in
that part of the Arctic within a couple of decades – could start a run-
away melting that will eventually raise sea levels worldwide by
seven metres’ (New Scientist, ‘Doomsday Scenario’, words attrib-
uted to Jonathan Gregory of the Hadley Centre, 22 November
2003). According to a BBC report (28 July 2004) the Greenland ice
sheet is melting ten times faster than previously thought. Since May
2004 the ice thickness has reduced by 2–3 m. The same report
stated that Alaska is 8C warmer than 30 years ago.](https://image.slidesharecdn.com/561979-250521125847-be8ad6c9/85/Architecture-In-A-Climate-Of-Change-2nd-Edition-Peter-F-Smith-33-320.jpg)
![Marey's sphygmograph was not the first instrument of its kind. There
had been, before it, Hérisson's sphygmometer, Ludwig's
kymographion, and the sphygmographs of Volckmann, King, and
Vierordt. But, if one compares a Vierordt tracing with a Marey
tracing, it will be plain that Marey's results were far advanced
beyond the useless oscillations isochrones recorded by Vierordt's
instrument.
Beside this improved sphygmograph, Chauveau and Marey also
invented the cardiograph, for the observation of the blood-pressure
within the cavities of the heart. Their cardiograph was a set of very
delicate elastic tambours, resting on the heart, or passed through
fine tubes into the cavities of the heart,[1]
and communicating
impulses to levers with writing-points. These writing-points, touching
a revolving cylinder, recorded the variations of the endocardial
pressure, and the duration of the auricular and ventricular
contractions.
It is impossible here to describe the subsequent study of those more
abstruse problems that the older physiologists had not so much as
thought of: the minutest variations of the blood-pressure, the
multiple influences of the nervous system on the heart and blood-
vessels, the relations between blood-pressure and secretion, the
automatism of the heart-beat, the influence of gravitation, and other
finer and more complex issues of physiology. But, even if one stops
at Marey's book, now more than forty years old, there is an
abundant record of good work, from the discovery of the circulation
to the invention of the sphygmograph.
II
THE LACTEALS
Asellius, in his account of his discovery of the lacteal vessels (1622),
is of opinion that certain of the ancients had seen these vessels,
but had not recognised them. He has a great reverence for](https://image.slidesharecdn.com/561979-250521125847-be8ad6c9/85/Architecture-In-A-Climate-Of-Change-2nd-Edition-Peter-F-Smith-61-320.jpg)
![was made by Jehan Pecquet of Dieppe, Madame de Sévigné's doctor,
her good little Pecquet. The full title of his book (2nd ed., 1654) is,
Expérimenta Nova Anatomica, quibus incognitum hactenus
Receptaculum, et ab eo per Thoracem in ramos usque subclavios
Vasa Lactea deteguntur. He has not the academical learning of
Asellius, nor his obsequious regard for the ancients; and the
discovery of the thoracic duct came, as it were by chance, out of an
experiment that was of itself wholly useless. He had killed an animal
by removing its heart, and then saw a small quantity of milky fluid
coming from the cut end of the vena cava—Albicantem subinde
Lactei liquoris, nec certe parum fluidi scaturiginem, intra Venæ Cavæ
fistulam, circ[=a] dextri sedem Ventriculi, miror effluere—and found
that this fluid was identical with the chyle in the lacteals. In another
experiment, he succeeded in finding the thoracic duct—At last, by
careful examination deep down along the sides of the dorsal
vertebræ, a sort of whiteness, as of a lacteal vessel, catches my
eyes. It lay in a sinuous course, close up against the spine. I was in
doubt, for all my scrutiny, whether I had to do with a nerve or with a
vessel. Therefore, I put a ligature a little below the clavicular veins;
and then the flaccidity above the ligature, and the swelling of the
distended duct below the ligature, broke down my doubt—Ergo
subducto paulo infra Claviculas vinculo, cum a ligaturâ sursum
flaccesceret, superstite deorsum turgentis alveoli tumore, dubium
meum penitus enervavit.... Laxatis vinculis, lacteus utrinque rivulus
in Cavam affatim Chylum profudit.
It is to be noted that Asellius and Pecquet, both of them, made their
discoveries as it were by chance. Unless digestion were going on,
the lacteals would be empty and invisible; and, on the dead body,
lacteals, receptaculum, and thoracic duct would all be empty. For
these reasons, it cost a vast number of experiments to prove the
existence, and to discover the course, of these vessels. Once found
in living animals, they could be injected and dissected in the dead
body; but they had been overlooked by Vesalius and the men of his
time.](https://image.slidesharecdn.com/561979-250521125847-be8ad6c9/85/Architecture-In-A-Climate-Of-Change-2nd-Edition-Peter-F-Smith-64-320.jpg)
![had the happy idea of proposing digestion as a subject
for a prize. Tiedemann and Gmelin in Germany, Leuret
and Lassaigne in France, submitted works of equal merit,
and the Academy divided the prize between them. The
work of Tiedemann and Gmelin is of especial interest to
us on account of the great number of their experiments,
from which came not only the absolute proof of the
existence of the gastric juice, but also the study of the
transformation of starch into glucose. Thus the theory of
digestion entered a new phase: it was finally recognised,
at least for certain substances, that digestion is not
simply dissolution, but a true chemical transformation.
(Cl. Bernard, loc. cit.)
In 1825 Dr. William Beaumont, a surgeon in the United States Army,
began his famous experiments on Alexis St. Martin, a young
Canadian travelling for the American Fur Company, who was shot in
the abdomen on 6th June 1822, and recovered, but was left with a
permanent opening in his stomach. Since the surgery of those days
did not favour an operation to close this fistula, Dr. Beaumont took
St. Martin into his service, and between 1825 and 1833 made a vast
number of experiments on him. These he published,[2]
and they
were of great value. But it is to be noted that the ground had been
cleared already, fifty years before, by Réaumur and Spallanzani:—
I make no claim to originality in my opinions, as it
respects the existence and operation of the gastric juice.
My experiments confirm the doctrines (with some
modifications) taught by Spallanzani, and many of the
most enlightened physiological writers. (Preface to Dr.
Beaumont's book.)
Further, it is to be noted that Alexis St. Martin's case proves that a
gastric fistula is not painful. Scores of experiments were made on
him, off and on, for nine years:—](https://image.slidesharecdn.com/561979-250521125847-be8ad6c9/85/Architecture-In-A-Climate-Of-Change-2nd-Edition-Peter-F-Smith-69-320.jpg)
![Claude Bernard's discovery of glycogen in the liver had a profound
influence both on physiology and on pathology. Take first its
influence on pathology. Diabetes was known to Celsus, Aretæus, and
Galen; Willis, in 1674, and Morton, in 1675, noted the distinctive
sweetness of the urine; and their successors proved the presence of
sugar in it. Rollo, in 1787, observed that vegetable food was bad for
diabetic patients, and introduced the strict use of a meat diet. But
Galen had believed that diabetes was a disease of the kidneys, and
most men still followed him: nor did Rollo greatly advance pathology
by following not Galen, but Aretæus. Later, with the development of
organic chemistry, came the work of Chevreuil (1815), Tiedemann
and Gmelin (1823), and other illustrious chemists: and the pathology
of diabetes grew more and more difficult:—
These observations gave rise to two theories: the one,
that sugar is formed with abnormal rapidity in the
intestine, absorbed into the blood, and excreted in the
urine; the other, that diabetes is due to imperfect
destruction of the sugar, either in the intestine or in the
blood. Some held that it underwent conversion into lactic
acid as it was passing through the intestinal walls, while
others believed it to be destroyed in the blood by means
of the alkali therein contained.[3]
Thus, before Claude Bernard (1813-1878), the pathology of diabetes
was almost worthless. And, in physiology, his work was hardly less
important than the work of Harvey. A full account of it, in all its
bearings, is given in Sir Michael Foster's Life of Claude Bernard
(Fisher Unwin, 1899).
In Bernard's Leçons sur le Diabète et la Glycogenèse Animale (Paris,
1877), there is a sentence that has been misquoted many times:—
Sans doute, nos mains sont vides aujourd'hui, mais notre
bouche peut être pleine de légitimes promesses pour
l'avenir.](https://image.slidesharecdn.com/561979-250521125847-be8ad6c9/85/Architecture-In-A-Climate-Of-Change-2nd-Edition-Peter-F-Smith-71-320.jpg)
![suprarenal capsules, to the whole chemistry of the blood and the
tissues. So far has physiology come, unaided by anatomy, from the
fantastic notions of Lindanus and the men of his time: and has come
every inch of the way by the help of experiments on animals.
Professor Starling's observations, on the chemical influence of the
duodenal mucous membrane on the flow of pancreatic fluid, have
advanced the subject still further.
VI
THE GROWTH OF BONE
The work of du Hamel proved that the periosteum is one chief agent
in the growth of bone. Before him, this great fact of physiology was
unknown; for the experiments made by Anthony de Heide (1684),
who studied the production of callus in the bones of frogs, were
wholly useless, and serve only to show that men in his time had no
clear understanding of the natural growth of bone. De Heide says of
his experiments:—
From these experiments it appears—forsan probatur—
that callus is generated by extravasated blood, whose
fluid particles being slowly exhaled, the residue takes the
form of the bone: which process may be further
advanced by deciduous halitus from the ends of the
broken bone.
And Clopton Havers, in his Osteologia Nova (London, 1691), goes so
far the wrong way that he attributes to the periosteum not the
production of bone, but the prevention of over-production; the
periosteum, he says, is put round the shaft of a bone to compress it,
lest it grow too large.
Du Hamel's discovery (1739-1743) came out of a chance
observation, made by John Belchier,[4]
that the bones of animals fed
near dye-works were stained with the dye. Belchier therefore put a
bird on food mixed with madder, and found that its bones had taken](https://image.slidesharecdn.com/561979-250521125847-be8ad6c9/85/Architecture-In-A-Climate-Of-Change-2nd-Edition-Peter-F-Smith-79-320.jpg)
![Galen's method of procedure was totally different to that
of an anatomist alone. He first reviewed the anatomical
position, and by dissection showed the continuity of the
nervous system, both central and peripheral, and also
that some bundles of nerve fibres were distributed to the
skin, others to the muscles. Later, by process of the
physiological experiment of dividing such bundles of
fibres, he showed that the former were sensory fibres
and the latter motor fibres. He further traced the nerves
to their origins in the spinal cord, and their terminations
as aforesaid. From these observations and experiments
he was able to deduce the all-important fact that different
nerve-roots supplied different groups of muscles and
different areas of the skin.... An excellent illustration of
his method, and of the fact that we ought not to treat
symptoms, but the causes of symptoms, is shown very
clearly in one of the cases which Galen records as having
come under his care. He tells us that he was consulted by
a certain sophist called Pausanias, who had a severe
degree of anæsthesia of the little and ring fingers. For
this loss of sensation, etc., the medical men who
attended him applied ointments of various kinds to the
affected fingers; but Galen, considering that that was a
wrong principle, inquired into the history, and found that
while the patient was driving in his chariot he had
accidentally fallen out and struck his spine at the junction
of the cervical and dorsal regions. Galen recognised that
he had to do with a traumatism affecting the eighth
cervical and first dorsal nerve; therefore, he says, he
ordered that the ointments should be taken off the hand
and placed over the spinal column, so as to treat the
really affected part, and not apply remedies to merely the
referred seat of pain.[5]
Galen, by this sort of work, laid the foundations of physiology; but
the men who came after him let his facts be overwhelmed by](https://image.slidesharecdn.com/561979-250521125847-be8ad6c9/85/Architecture-In-A-Climate-Of-Change-2nd-Edition-Peter-F-Smith-82-320.jpg)
![The great authority of Sir Charles Bell has been quoted a thousand
times against all experiments on animals:—
Experiments have never been the means of discovery;
and a survey of what has been attempted of late years in
physiology, will prove that the opening of living animals
has done more to perpetuate error than to confirm the
just views taken from the study of anatomy and natural
motions.
He wrote, of course, in the days before bacteriology, before
anæsthetics; he had in his mind neither inoculations, nor any
observations made under chloroform or ether, but just the opening
of living animals. He had also in his mind, and always in it, a great
dislike against the school of Magendie. Let all that pass; our only
concern here is to know whether these words are true of his own
work.
They occur in a paper, On the Motions of the Eye, in Illustration of
the Uses of the Muscles and Nerves of the Orbit; communicated by
Sir Humphry Davy to the Royal Society, and read March 20, 1823.[6]
This essay was one of a series of papers on the nervous system,
presented to the Royal Society during the years 1821-1829. In 1830,
having already published four of these papers under the title, The
Exposition of the Nervous System, Bell published all six of them,
under the title, The Nervous System of the Human Body.
In his Preface to this book (1830) he quotes the earliest of all his
printed writings on the nervous system, a pamphlet, printed in 1811,
under the title, An Idea of a New Anatomy of the Brain, Submitted
for the Observation of the Authors Friends. We have therefore two
statements of his work, one in 1811, the other in 1823 and 1830.
The first of them was written when his work was still new before his
eyes.
Those who say that experiments did not help Bell in his great
discovery—the difference between the anterior and the posterior](https://image.slidesharecdn.com/561979-250521125847-be8ad6c9/85/Architecture-In-A-Climate-Of-Change-2nd-Edition-Peter-F-Smith-85-320.jpg)
Architecture In A Climate Of Change 2nd Edition Peter F Smith
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- 6. Architecture in a Climate of Change
- 8. Architecture in a Climate of Change A guide to sustainable design Peter F. Smith AMSTERDAM • BOSTON • HEIDELBERG • LONDON • NEW YORK • OXFORD PARIS • SAN DIEGO • SAN FRANCISCO • SINGAPORE • SYDNEY • TOKYO Architectural Press is an imprint of Elsevier
- 9. Architectural Press An imprint of Elsevier Linacre House, Jordan Hill, Oxford OX2 8DP 30 Corporate Drive, Burlington, MA 01803 First published 2001 Second edition 2005 Copyright © 2001, 2005, Peter F. Smith. All rights reserved The right of Peter F. Smith to be identified as the author of this work have been asserted in accordance with the Copyright, Designs, and Patents Act 1988 No part of this publication may be reproduced in any material form (including photocopying or storing in any medium by electronic means and whether or not transiently or incidentally to some other use of this publication) without the written permission of the copyright holder except in accordance with the provision of the Copyright, Designs, and Patents Act 1988 or under the terms of a licence issued by the Copyright Licensing Agency Ltd, 90 Tottenham Court Road, London, England W1T 4LP. Applications for the copyright holder’s written permission to reproduce any part of this publication should be addressed to the publisher. Permissions may be sought directly from Elsevier’ Science and Technology Rights Department in Oxford, UK: phone: (44) (0) 1865 843830; fax: (44) (0) 1865 853333; e-mail: permission@elsevier.co.uk. You may also complete your request on-line via the Elsevier homepage (http://www.elsevier.com), by selecting “Customer Support” and then “Obtaining Permissions”. British Library Cataloguing in Publication Data A catalogue record for this book is available from the British Library ISBN 0 7506 65440 Typeset by Newgen Imaging Systems Pvt Ltd, Chennai, India Printed and bound in Great Britain For information on all Architectural Press publication visit our web site at http://books.elsevier.com
- 10. Contents v Foreword xi Acknowledgements xii Introduction xiii 1 Climate change – nature or human nature? 1 The carbon cycle 1 The greenhouse effect 2 Climate change – the paleoclimate record 3 Causes of climate fluctuation 4 The evidence 7 2 Predictions 12 Recent uncertainties 17 What is being done? 19 The outlook for energy 20 The nuclear option 23 3 Renewable technologies – the marine environment 26 The UK energy picture 26 Energy from rivers and seas 28 Hydroelectric generation 28 Small-scale hydro 29 ‘Run of river’ systems 29 Tidal energy 30 4 Renewable technologies – the wider spectrum 42 Passive solar energy 42 Active solar 42 Solar thermal electricity 43 The parabolic solar thermal concentrator 44 Photovoltaics 45 Wind power 45 Biomass and waste utilisation 47
- 11. Hydrogen 50 Nuclear power 50 5 Low energy techniques for housing 52 Construction systems 52 Solar design 54 Types of solar thermal collector 62 Windows and glazing 64 6 Insulation 68 The range of insulation options 69 High and superinsulation 72 Transparent insulation materials 77 Insulation – the technical risks 77 7 Domestic energy 80 Photovoltaic systems 80 Micro-combined heat and power (CHP) 87 Fuel cells 90 Embodied energy and materials 91 8 Advanced and ultra-low energy houses 93 The Beddington Zero Energy Development – BedZED 94 The David Wilson Millennium Eco-House 94 Demonstration House for the Future, South Wales 95 The prospects for wood 98 The external environment 103 Summary checklist for the energy efficient design of dwellings 104 Report by Arup Research and Development for the DTI’s Partners in Innovation Programme 2004 107 9 Harvesting wind and water 108 Small wind turbines 108 Types of small-scale wind turbine 110 Building integrated systems 114 Conservation of water in housing 115 Domestic appliances 117 10 Existing housing: a challenge and opportunity 118 The remedy 121 Case study 122 11 Low energy techniques for non-domestic buildings 127 Design principles 127 Environmental considerations in the design of offices 128 Passive solar design 129 CONTENTS vi
- 12. 12 Ventilation 138 Natural ventilation 138 Internal air flow and ventilation 138 Unassisted natural ventilation 140 Mechanically assisted ventilation 145 Cooling strategies 151 Evaporative cooling 152 Additional cooling strategies 154 The ecological tower 154 Summary 160 Air conditioning 161 13 Energy options 162 The fuel cell 163 Proton exchange membrane fuel cell 164 Phosphoric acid fuel cell (PAFC) 165 Solid oxide fuel cell (SOFC) 165 Alkaline fuel cell (AFC) 166 Moltel carbonate fuel cell (MCFC) 166 Storage techniques – electricity 169 Photovoltaic applications 170 Heat pumps 171 Energy storage – heating and cooling 174 Seasonal energy storage 176 Electricity storage 177 Building management systems 178 Tools for environmental design 179 Report by Arup Research and Development for the DTI’s Partners in Innovation Programme 2004 180 14 Lighting – designing for daylight 181 Design considerations 182 The atrium 184 Light shelves 185 Prismatic glazing 185 Light pipes 185 Holographic glazing 187 Solar shading 187 15 Lighting – and human failings 188 Photoelectric control 189 Glare 190 Dimming control and occupancy sensing 190 Switches 191 System management 191 CONTENTS vii
- 13. Air conditioned offices 192 Lighting – conditions for success 192 Summary of design considerations 193 16 Cautionary notes 195 Why do things go wrong? 195 High profile/low profile 196 The ‘high-tech demand’ 196 Operational difficulties 197 Building related illness 197 Inherent inefficiencies 197 Common architectural problems 198 Common engineering problems 198 Avoiding air conditioning – the issues 198 Common failures leading to energy waste 199 The human factor 199 Summary of recommendations 200 Conclusions 200 17 Life-cycle assessment and recycling 202 Waste disposal 202 Recycling 203 Life-cycle assessment 205 Whole life costing 205 Eco-materials 206 External finishes 207 Paints 207 Materials and embodied energy 208 Low energy Conference Centre, Earth Centre, Doncaster 209 Recycling strategy checklist 211 18 State of the art case studies 212 The National Assembly for Wales 212 Zuckermann Institute for Connective Environmental Research (ZICER) 214 Social housing 217 Beaufort Court, Lillie Road, Fulham, London, 2003 217 Beddington Zero Energy Development (BedZED) 218 Beaufort court renewable energy centre zero emissions building 225 19 Integrated district environmental design 235 Ecological City of Tomorrow, Malmo, Sweden 236 Towards the less unsustainable city 238 CONTENTS viii
- 14. 20 An American perspective 245 Glenwood Park, Atlanta, Georgia 248 21 Emergent technologies and future prospects 250 Energy for the future 251 Next generation solar cells 254 Artificial photosynthesis 256 Energy storage 256 Hydrogen storage 257 Flywheel technology 257 Advances in lighting 258 The photonic revolution 259 Smart materials 260 Smart fluids 261 Socio-economic factors 262 Appendix 1 Key indicators for sustainable design 265 Appendix 2 An outline sustainability syllabus for designers 267 Index 275 CONTENTS ix
- 16. Foreword This updated book is essential reading especially as it considers the ‘why’ as well as the ‘what’ of sustainable architecture. There is now wide agreement that halting global warming and its climatic consequences is likely to be the greatest challenge that we shall face in this century. As populations increase and, at the same time, gravitate to cities, build- ings old and new should be a prime target in the battle to reverse the demand for fossil-based energy. Students and practitioners alike within the construction industry need to be aware of the importance of their role in creating architecture which not only raises the quality of life but also ensures that such quality is sustainable. Lord Rogers of Riverside xi
- 17. Acknowledgements I should like to express my thanks to the following practices for their help in providing illustrations and commenting on the text: Bennetts Associates, Bill Dunster Architects, Foster and Partners, Michael Hopkins and Partners, Jestico Whiles, RMJM, Richard Rogers Partnership, Alan Short Architects, Fielden Clegg Bradley, Studio E Architects, David Hammond Architects, Grimshaw Architects Ove Arup and Partners. I am also indebted to Dr Randall Thomas for his valuable advice on the text, Dr William Bordass for providing information from his ‘Probe’ studies, Dr Adrian Pitts of Sheffield University, Nick White of the Hockerton Housing Project, Ray Morgan of Woking Borough Council and finally Rick Wilberforce of Pilkington plc for keeping me up to date with developments in glazing. xii
- 18. Introduction This book calls for changes in the way we build. For change to be widely accepted there have to be convincing reasons why long-established prac- tices should be replaced. The first part of the book seeks to set out those reasons by arguing that there is convincing evidence that climate changes now under way are primarily due to human activity in releasing carbon dioxide (CO2) into the atmosphere. Buildings are particularly implicated in this process, being presently responsible for about 47 per cent of carbon dioxide emissions across the 25 nations of the European Union. This being the case it is appropriate that the design and construction of build- ings should be a prime factor in the drive to mitigate the effects of climate change. One of the guiding principles in the production of buildings is that of integrated design, meaning that there is a constructive dialogue between architects and services engineers at the inception of a project. The book is designed to promote a creative partnership between the professions to produce buildings which achieve optimum conditions for their inhabitants whilst making minimum demands on fossil-based energy. A difficulty encountered by many architects is that of persuading clients of the importance of buildings in the overall strategy to reduce carbon dioxide emissions. The first chapters of the book explain the mechanism of the greenhouse effect and then summarise the present situation vis-à-vis global warming and climate change. This is followed by an outline of the international efforts to curb the rise in greenhouse gases. The purpose is to equip designers with persuasive arguments as to why this approach to architecture is a vital element in the battle to avoid the worst excesses of climate change. At the same time it is important to appreciate that there are absolute limits to the availability of fossil fuels, a problem that will gather momentum as developing countries like China and India main- tain their dramatic rates of economic growth. China may well serve to give a foretaste of the future. By 2005 it had reached 1.3 billion population; at this rate by 2030 it will reach 1.6 billion. The crucial factor is that the great bulk of this population is concentrated in the great valleys of the Yangtze and Yellow Rivers and xiii
- 19. their tributaries, an area about the size of the USA. China is on the verge of consuming more than it can produce. By 2025 it will be import- ing 175 million tonnes of grain per year and by 2030 200 million tonnes, which equals present total world exports (US National Intelligence Council). Its appetite for steel and building materials is voracious and already pushing up world prices. A supply of energy sufficient to match the rate of economic growth is China’s prime concern. Between January and April 2004 demand for energy rose 16 per cent. In 2003 it spent £13 billion on hydroelectric, coal fired and nuclear power plants – a rate of expansion that equals Britain’s entire electrical output every two years. According to a spokesman for the Academy of Engineering of China, the country will need an additional supply equivalent to four more Three Gorges hydro- electric dams, 26 Yanzhou coal mines, six new oil fields, eight gas pipelines, 20 nuclear power stations and 400 thermal power generators. Carbon has been slowly locked in the earth over millions of years creating massive fossil reserves. The problem is that these reserves of carbon are being released as carbon dioxide into the atmosphere at a rate unprecedented in the paleoclimatic record. The pre-industrial atmospheric concentration of CO2 was around 270 parts per million by volume (ppmv). Today it is approximately 380 ppmv and is rising by about 20 ppmv per decade. The aim of the scientific community is that we should stabilise atmospheric CO2 at under 500 ppmv by 2050 acknowledging that this total will nevertheless cause severe climate damage. However, if the present trend is maintained we could expect concentrations exceeding 800 ppmv by the second half of the century. Given the absence of a political consensus following the refusal of the US to ratify the Kyoto Protocol, the 800 plus figure looks ever more likely unless there are widespread and radical strategies that bypass political agreements, and this is where architects and engineers have a crucial part to play. The Earth receives annually energy from the sun equivalent to 178 000 terawatt years which is around 15000 times the present world- wide energy consumption. Of that, 30 per cent is reflected back into space, 50 per cent is absorbed and re-radiated, and 20 per cent powers the hydrological cycle. Only 0.6 per cent powers photosynthesis from which all life derives and which created our reserves of fossil fuel. The security of the planet rests on our ability and willingness to use this free energy without creating unsavoury side effects, like the range of pollu- tants released by the burning of fossil fuels. The greatest potential for realising this change lies in the sphere of buildings, which, in the UK, account for almost 50 per cent of all CO2 emissions. The technology exists to cut this by half in both new and existing buildings. Already demonstration projects have proved that reductions can reach 80–90 per cent against the current norm. The opportunity rests with architects and services engineers to bring about this step-change in the way buildings are designed. In the 1960s–1970s buildings were symbols INTRODUCTION xiv
- 20. of human hubris, challenging nature at every step. The turn of the millennium saw a new attitude gathering momentum in a synergy between human activity and the forces of nature. Nowhere can this be better demonstrated than in the design of buildings. In 2000 the Royal Commission on Environmental Pollution pro- duced a report on Energy – The Changing Climate. It concludes: ‘To limit the damage beyond that which is already in train, large reductions of global emissions will be necessary during this century and the next. Strong and effective action has to start immediately.’ Peter F. Smith January 2005 INTRODUCTION xv
- 22. Chapter One 1 Climate change – nature or human nature? The key question is this: climate change is now widely accepted as being a reality, so, is it a natural process in a sequence of climate changes that have occurred over the paleoclimatic record or is it being driven by humans? If we hold to the former view then all we can hope for is to adapt as best we can to the climate disruption. On the other hand, if we accept that it is largely human induced, then it follows that we ought to be able to do something about it. There is widespread agreement among climate scientists worldwide that the present clear evidence of climate change is 90 per cent certain to be due to human activity mainly though the burning of fossil-based energy. This should be good enough to persuade us that human action can ultimately put a brake on the progress of global warming and its climate consequences. Once the issues are understood, a commitment to renewable energy sources and bioclimatic architectural design should become unavoidable. Inspiring that commitment is the purpose of the first part of the book which then goes on to illustrate the kind of architecture that will have to happen as part of a broader campaign to avert the apoca- lyptic prospect of catastrophic climate change. The carbon cycle Carbon is the key element for life on Earth. Compounds of the element form the basis of plants, animals and micro-organisms. Carbon com- pounds in the atmosphere play a major part in ensuring that the planet is warm enough to support its rich diversity of life. The mechanism of the carbon cycle operates on the basis that the carbon locked in plants and animals is gradually released into the atmosphere after they die and decompose. This atmospheric carbon is then taken up by plants which convert carbon dioxide (CO2) into stems, trunks, leaves, etc. through photosynthesis. The carbon then enters the food chain as the plants are eaten by animals. There is also a geochemical component to the cycle mainly consisting of deep ocean water and rocks. The former is estimated to
- 23. contain 36 billion tonnes and the latter 75 million billion tonnes of carbon. Volcanic eruptions and the weathering of rocks release this carbon at a relatively slow rate. Under natural conditions the release of carbon into the atmos- phere is balanced by the absorption of CO2 by plants. The system is in equilibrium, or would be if it were not for human interference. The main human activity responsible for overturning the balance of the carbon cycle is the burning of fossil fuels which adds a further 6 billion tonnes of carbon to the atmosphere over and above the natural flux each year. In addition, when forests are converted to cropland the carbon in the vegetation is oxidised through burning and decomposition. Soil cultivation and erosion add further carbon dioxide to the atmosphere. If fossil fuels are burnt and vegetation continues to be destroyed at the present rate, the CO2 in the atmosphere will treble by 2100. Even if there is decisive action on a global scale to reduce carbon emissions, atmospheric concentrations will still double by this date. With the present fuel mix, every kilowatt hour of electricity used in the UK releases one kilogram of CO2. The burning of one hectare of forest gives off between 300 and 700 tonnes of CO2. These are some of the factors which account for the serious imbal- ance within the carbon cycle which is forcing the pace of the green- house effect which, in turn, is pushing up global temperatures. The greenhouse effect A variety of gases collaborate to form a canopy over the Earth which causes some solar radiation to be reflected back from the atmosphere, thus warming the Earth’s surface, hence the greenhouse analogy. The greenhouse effect is caused by long-wave radiation being reflected by the Earth back into the atmosphere and then reflected back by trace gases in the cooler upper atmosphere, thus causing additional warming of the Earth’s surface (Figure 1.1). The main greenhouse gases are water vapour, carbon dioxide, methane, nitrous oxide and tropospheric ozone (the troposphere is the lowest 10–15 kilometres of the atmosphere). The sun provides the energy which drives weather and climate. Of the solar radiation which reaches the Earth, one third is reflected back into space and the remainder is absorbed by the land, biota, oceans, ice caps and the atmosphere. Under natural conditions the solar energy absorbed by these features is balanced by outgoing radiation from the Earth and atmosphere. This terrestrial radiation in the form of long- wave, infra-red energy is determined by the temperature of the Earth- atmosphere system. The balance between radiation and absorption can change due to natural causes such as the 11-year solar cycle. Without the greenhouse shield the Earth would be 33C cooler, with obvious consequences for life on the planet. ARCHITECTURE IN A CLIMATE OF CHANGE 2
- 24. Since the industrial revolution, the combustion of fossil fuels and deforestation has resulted in an increase of 26 per cent in carbon dioxide concentrations in the atmosphere. In addition, rising popula- tion in the less developed countries has led to a doubling of methane emissions from rice fields, cattle and the burning of biomass. Methane is a much more powerful greenhouse gas than carbon dioxide. Nitrous oxide emissions have increased by 8 per cent since pre-industrial times (IPCC 1992). Climate change – the paleoclimate record In June 1990 scientists were brought up sharp by a graph which appeared in the journal Nature (Figure 1.2). It was evidence from ice core samples which showed a remarkably close correlation between temperature and concentrations of CO2 in the atmosphere from 160 000 years ago until 1989. It also revealed that present concentra- tions of CO2 are higher than at any time over that period. Since then the rate of increase has, at the very least, been maintained. Ice core samples give information in four ways. First, their melt layers provide an indication of the time span covered by the core. Second, a measurement of the extent to which ice melted and refroze after a given summer gives a picture of the relative warmth of that sum- mer. A third indicator is the heavy oxygen isotope 18 O in air trapped in the ice. It is more abundant in warm years. Finally, the air trapped in the snow layers gives a measurement of the CO2 in the atmosphere in a Figure 1.1 The greenhouse ‘blanket’ CLIMATE CHANGE – NATURE OR HUMAN NATURE? 3 Earth’s surface a year
- 25. given year. Other data from ice cores show that, at the peak of the last ice age 20 000 years ago, sea level was about 150 m lower than today. Another source of what is called ‘proxy’ evidence comes from analysing tree rings. This can give a snapshot of climate going back 6000 years. Each tree ring records one year of growth and the size of each ring offers a reliable indication of that year’s climate. The thicker the ring, the more favourable the climate to growth. In northern latitudes warmth is the decisive factor. Some of the best data come from within the Arctic Circle where pine logs provide a 6000-year record. The Climate Research Unit of the University of East Anglia has made a special study of the evidence for climate changes from different sources and has concluded that there is a close affinity between ice core evi- dence and that obtained from tree rings. Also instrumental records going back to the sixteenth century are consistent with the proxy evidence. Causes of climate fluctuation To be able to see the current changes in climate in context, it will be necessary to consider the causes of dramatic changes in the past. A major cause of climate fluctuation has been the variation in the Earth’s axial tilt and the path of its orbit round the sun. The Earth is subject to the influence of neighbouring planets. Their orbits produce a fluctuating gravitational pull on the Earth, affecting the angle of its Figure 1.2 Correspondence between historic temperature and carbon dioxide ARCHITECTURE IN A CLIMATE OF CHANGE 4
- 26. axis. As the Earth wobbles, vast ice sheets wax and wane over a cycle called a Milankovitch cycle. However, thanks to the stabilising pull of the moon, the variation in tilt is contained within limits which preserves the integrity of the seasons. Without the moon, the axis could move to 90 degrees from the vertical meaning that half the planet would have permanent summer and the other endless winter. It has been calculated that the current orbital configuration is sim- ilar to that of the warm interglacial period 400 000 years ago. We may indeed be in the early stages of an interglacial episode and the accom- panying natural warming which is being augmented by human induced warming. (For more information on climate fluctuations over the past million years see Houghton J. (2004) Global Warming, 3rd edn, Cambridge University Press.) A second factor forcing climate change is the movement of tec- tonic plates and the resultant formation of volcanic mountains. In them- selves mountains add to the stirring effect on the atmosphere in concert with the rotation of the Earth. They also generate fluctuations in atmospheric pressure, all of which affect climate. But it is volcanic activity which can cause dramatic changes. The surface of the Earth is constantly shifting. The collision of plates accounts for the formation of mountains. A feature of plate tectonics is that, when plates collide, one plate slides under the other; this is called subduction. In the process rocks are heated and forced through the surface as volcanoes, releasing vast quantities of debris and CO2 in the process. In the short term this can lead to a cooling as the dust cuts out solar radiation. In the longer term, large injections of CO2 lead to warm- ing, since CO2 has a relatively long life in the atmosphere. A third factor may be a consequence of the second. Paleoclimate data show that there have been periodic surges of ice flows into the north Atlantic which, in turn, affect the deep ocean currents, notably the Gulf Stream. To understand why the ice flows affect the Gulf Stream we need to look at what drives this rather special current. Particularly salty and warm surface water migrates from the tropics towards the north Atlantic. As it moves north it gradually becomes cold and dense, and, as a consequence, near Greenland it plunges to the ocean floor. This, in turn, draws warmer water from the tropics which is why it is also called the conveyor belt or deep ocean pump. It accounts for 25 per cent of the heat budget of northwest Europe. So, what is the relevance of the icebergs? As these armadas of icebergs melted as they came south they produced huge amounts of fresh water which lowered the density of surface water undermining its ability to descend to the ocean floor. The effect was to shut down the conveyor belt. As a result northern Europe was periodically plunged into arctic conditions and scientists are concerned that there is now evidence that this process is beginning to happen due to melting ice in the southern tip of Greenland. After the melted iceberg water had dispersed, the conveyor started up again CLIMATE CHANGE – NATURE OR HUMAN NATURE? 5
- 27. leading to rapid warming. This cycle occurred 20 times in 60 000 years, and the evidence indicates that cooling was relatively slow whilst warm- ing was rapid – 10–12C in a lifetime. For some reason these forays of icebergs stopped about 8000 years ago, creating relatively stable conditions which facilitated the development of agriculture and ultimately the emergence of urban civilisations. A fourth factor may seem ironic, because ice ages can be triggered by warm spells leading to the rapid expansion of forests. This, in turn, leads to huge demands for CO2 which is drawn from the atmosphere. The result of this stripping of atmospheric CO2 is a weakening of the greenhouse shield, resulting in sharply dropping temperatures. Changes in energy levels emitted by the sun are also implicated in global fluctuations. In June 1999 the journal Nature (vol. 399, p. 437) published research evidence from the Rutherford Appleton Laboratory in Didcot, Oxfordshire which suggests that half the global warming over the last 160 years has been due to the increasing brightness of the sun. However, since 1970 the sun has become less responsible for the warming, yet the rate of warming has been increasing, indicating that increased greenhouse gases are the culprit. Some of the best evidence for the climatic effects of varying levels of radiative output from the sun comes from Africa. Sediment in Lake Naivasha in the Kenya Rift Valley reveals the levels of lake water over the past 1000 years. Periods of high water have higher concentrations of algae on the lake floor which trans- lates to a higher carbon content in the annual layers of sediment. There were long periods of intense drought leading to famine and mass migrations, the worst being from 1000 to 1270 (Nature, vol. 403, p. 410). Finally, we cannot ignore wider cosmic effects. The dinosaurs will testify to the effect on climate of meteor strikes creating perpetual night. New sites of catastrophic impacts are still being discovered on the Earth, but if we want a true picture of the historic record of meteor impact we can see it on Venus. The stability of that planet – no plate movement or vegetation to hide the evidence – ensures that we have a picture of meteor bombardment over hundreds of millennia. The Earth will have been no different. There is strong historic evidence that life on Earth has a precarious foothold. The palaeontological record shows that there have been five mass extinctions in the recorded history of the planet. The most widely known on the popular level is the final one which occurred at the end of the Cretacious period 65 million years ago. It is widely attributed to one or more massive meteorites that struck the Earth propelling huge quan- tities of debris into the atmosphere masking the sun probably for years. Photosynthesising plants were deprived of their energy source and food chains collapsed resulting in the extinction of 75–80 per cent of species, notably the dinosaurs. However, of all the other mass extinctions, it is the third in the sequence that warrants most attention because it has contemporary ARCHITECTURE IN A CLIMATE OF CHANGE 6
- 28. relevance. At the end of the Permian period, 251 million years ago, a catastrophic chain of events caused the extinction of 95 per cent of all species on Earth. The prime cause was a massive and prolonged period of volcanic eruptions, not from mountains but from extensive fissures in the ground in the region which ultimately became Siberia. A chain of events caused massive expulsions of CO2 into the atmosphere which led to rapid warming and plant growth. This had the effect of stripping much of the oxygen from the atmosphere leading to a collapse of much of the biosphere. Plants and animals literally suffocated. For the next 5 million years the remaining 5 per cent of species clung to a precarious existence. It took 50 million years for the planet to return to anything like the previous rate of biodiversity (New Scientist, 26 April 2003, ‘Wipeout’). The importance of this evidence lies in the fact that this mass extinction occurred because the planet warmed by a mere 6C over a relatively short period in the paleoclimate timescale. Why this should concern us now is because the world’s top climate scientists on the United Nations Inter-Governmental Panel on Climate Change (IPCC 2002) estimated that the Earth could warm to around 6C by the latter part of the century unless global CO2 emissions are reduced by 60 per cent by 2050 against the emissions of 1990. It is the widescale evidence of anomalous climatic events cou- pled with the rate at which they are occurring that has persuaded the IPCC scientists that much of the blame lies with human activity. The evidence ● There has been a marked increase in the incidence and severity of storms over recent decades. Over the past 50 years high pressure systems have increased by an average of three millibars whilst low pressure troughs have deepened by the same amount, thereby intensifying the dynamics of weather systems. Greater extremes of the hydrological cycle are leading, on the one hand, to increased area of desert, and, on the other, greater intensity of rain storms which increase run-off and erosion of fertile land. In both cases there is a loss of carbon fixing greenery and food producing land. ● In the first months of 2000 Mozambique experienced catastrophic floods which were repeated in 2001. In 2002 devastating floods occurred across Europe inundating historic cities like Prague and Dresden creating ‘one of the worst flood catastrophes since the Middle Ages’ (Philippe Busquin, European Union Research Commissioner). The following year saw a similar occurrence with the rivers Elbe and Rhone bursting their banks. ● In July 2004 Southeast Asia experienced catastrophic floods due to exceptional rainfall, rendering 30 million homeless in Bangladesh and the Indian state of Bihar. At the same time central China also CLIMATE CHANGE – NATURE OR HUMAN NATURE? 7
- 29. suffered devastating floods whilst Delhi experienced a major draught. The people of Ethiopia are facing starvation in their millions because of the year-by-year failure of the rains. ● Insurance companies are good barometers of change. One of the largest, Munich Re, states that claims due to storms have doubled in every decade since 1960. In that decade there were 16 disasters costing £30 billion. In the last decade of the century there were 70 disasters costing £250 billion. In the first years of this century the pace has quickened. Munich Re has reported that the 700 natural disasters in 2003 claimed 50 000 lives and cost the insurers £33 billion. The Loss Prevention Council has stated that, by the middle of this century, losses will be ‘unimaginable’. Yet, these extreme climatic events are only part of the scenario of global warming. ● Besides the effect of increasingly steep pressure gradients another factor contributing to the intensification of storms is the contraction of snow fields. These have in the past created high pressure zones of cold stable air which have kept at bay the Atlantic lows with their attendant storms. This barrier has weakened and shifted further east allowing the storms to reach western Europe. The increased frequency of storms and floods in this area during the last decade of the twentieth century adds weight to this conclusion. ● El Niño has produced unprecedentedly severe effects due to the warming of the Pacific. There is even talk that the El Niño reversal may become a fixture which would have dire consequences for Australia and Southeast Asia. ● Receding polar ice is resulting in the rapid expansion of flora; Antarctic summers have lengthened by up to 50 per cent since the 1970s and new species of plants have appeared as glaciers have retreated. In Iceland Europe’s largest glacier is breaking up and is likely to slide into the north Atlantic within the next few years, high- lighting the threat to sea levels from land-based ice (The Observer, 22 October 2000). The Arctic ice sheet has thinned by 40 per cent due to global warming (report by an international panel of climate scientists, January 2001). ● Sea level has risen 250 mm (10 inches) since 1860. Up to now much of the sea level rise has been due to thermal expansion. ● Sea temperatures in Antarctica are rising at five times the global average, at present a 2.5C increase since the 1940s. The major threat lies with the potential break-up of land-based ice. The recent breakaway of the 12 000 sq. km of the Larson B ice shelf has serious implications. In itself it will not contribute to rising sea levels. The danger lies in the fact that the ice shelves act as a bulwark support- ing the land-based ice. In the May 2003 edition of Scientific American it was reported that, following the collapse of the Larson ice shelf ‘inland [land based] glaciers have surged dramatically towards the coast in recent years’. Satellite measurements have shown that the two main glaciers have advanced 1.25 and 1.65 km ARCHITECTURE IN A CLIMATE OF CHANGE 8
- 30. respectively. That represents a rate of 1.8 and 2.4 metres per day. When the West Antarctic ice sheet totally collapses, as it will, this will raise sea level by 5 m (Scientific American, op. cit., p. 22). In April 1999 The Guardian reported that this ice shelf was breaking up 15 times faster than predicted. Even more disconcerting is the fact that the largest glacier in Antarctica, the Pine Island glacier, is rapidly thinning – 10 metres in eight years – and accelerating towards the sea at a rate of 8 metres a day. This is another indica- tion of the instability of the West Antarctic ice sheet. ● At the same time there has been massive melting of glacier ice on mountains. The Alps have lost 50 per cent of their ice in the past century. The International Commission on Snow and Ice has reported that glaciers in the Himalayas are receding faster than anywhere else on Earth. ● In Alaska there is general thinning and retreating of sea ice, drying tundra, increasing storm intensity, reducing summer rainfall, warmer winters and changes in the distribution, migration patterns and numbers of some wildlife species. Together these pose serious threats to the survival of the subsistence-indigenous Eskimos (New Scientist, 14 November 1998). ● From Alaska to Siberia, serious infrastructure problems are occur- ring due to the melting of the permafrost. Roads are splitting apart, trees keeling over, houses subsiding and world famous ski resorts becoming non-viable. In Alaska and much of the Arctic tempera- tures are rising ten times faster than the global average – 4.4C in 30 years. This may, in part, be due to the melting of the snow fields exposing tundra. Whilst snow reflects much of the solar radiation back into space, the bare tundra absorbs heat, at the same time releasing huge amounts of carbon dioxide into the atmosphere – a classic positive feedback situation. The village of Shishmaref on an island on the edge of the Arctic Circle is said to be ‘the most extreme example of global warming on the planet’ and ‘is literally being swallowed by the sea’. Some houses have already fallen into the sea; others are crumbling due to the melting of the permafrost supporting their foundations. The sea is moving inland at the rate of 3 m a year (BBC News, 23 July 2004). ● Global mean surface air temperature has increased between 0.3 and 0.6C since the later nineteenth century. The average global surface temperature in 1998 set a new record surpassing the previ- ous record in 1995 by 0.2C – the largest jump ever recorded (Worldwatch Institute in Scientific American, March 1999). The warmest year on record was 1999. Global warming is increasing at a faster rate than predicted by the UN IPCC scientists in 1995. They anticipated that temperatures would rise between 1 and 3.5C in the twenty-first century. According to the Director of the US National Climate Data Center, in only a short time the rate of warming is already equivalent to a 3C rise per century. This makes it probable CLIMATE CHANGE – NATURE OR HUMAN NATURE? 9
- 31. that the end of century temperature level will be significantly higher than the IPCC top estimate (Geophysical Research Letters, vol. 27, p. 719). ● NASA scientists report satellite evidence of the Greenland land- based ice sheet thinning by 1 m per year. Altogether it has lost 5 m in southwest and east coasts. On the one hand, this threatens the Gulf Stream or deep ocean pump and on the other, it leads directly to a rise in sea level, threatening coastal regions (Nature, 5 March 1999). Over the past 20 years the polar ice cap has thinned by 40 per cent. ● Concentrations of CO2 in the atmosphere are increasing at a steep rate. The pre-industrial level was 590 billion tonnes or 270 parts per million by volume (ppmv); now it is 760 billion tonnes or around 380 ppmv and rising 1.5–2 ppmv per year. Most of the increase has occurred over the last 50 years. According to Sir David King, UK Chief Government Scientist, this is the highest concentration in 55 million years. Then there was no ice on the planet. The previous highest concentration was 300 ppmv 300 000 years ago (New Scientist, 29 January 2000, pp. 42–43). At the present rate of emis- sion, concentrations could reach 800–1000 ppmv by 2100. Even if emissions were to be reduced by 60 per cent against 1990 levels by 2050 this will still raise levels to over 500 ppmv with unpredictable consequences due to the fact that CO2 concentrations survive in the atmosphere for at least 100 years. ● Altogether it would seem that a temperature rise of at least 6C is very possible with the worst case scenario now rising to 11.5C. Bearing in mind the observed rate of temperature increase as mentioned above, the aim now should be to prevent the planet crossing the threshold into runaway global warming whereby mutu- ally reinforcing feedback loops become unstoppable. ● Spring in the northern hemisphere is arriving at least one week earlier than 20 years ago; some estimates put it at 11 days. A 40-year survey by Nigel Hepper at the Royal Botanical Gardens at Kew involving 5000 species indicates that spring is arriving ‘several weeks earlier’. A study of European gardens found that the growing season has expanded by at least ten days since 1960. Munich scientists studied 70 botanical gardens from Finland to the Balkans (616 spring records and 178 autumn). The conclusion was that spring arrived on average six days earlier and autumn five days later over a 30-year period (Nature, February 1999). ● Extreme heat episodes are becoming a feature of hitherto temperate climate zones. The majority of heat-related deaths are due to a lethal assault on the blood’s chemistry. Water is lost through sweat- ing and this leads to higher levels of red blood cells, clotting factors and cholesterol. The process starts within 30 minutes of exposure to sun. The summer of 2003 saw heatwaves across Europe that were exceptional, not only in terms of peak temperatures but also their ARCHITECTURE IN A CLIMATE OF CHANGE 10
- 32. duration. According to the Earth Policy Institute in Washington DC, 35 000 died in August across Europe and 14 800 in France alone from heat-related causes. Other estimates put the figures at 20 000 and 11 000 respectively. According to scientists in Zurich reporting in ‘Nature on-line’, this kind of sustained summer temperature could normally be expected every 450 years. Towards the latter part of the century they predict such an event every second year. On 4 February 2004 the temperature in central England reached 12.5C which was the highest early February temperature since records began in 1772 according to the UK Meteorological Office. That month was also the occasion of a severe heatwave in Brisbane, North Australia, where there were 29 sudden deaths in one night. ● One of the predicted results of global warming is that there will be greater extremes of weather, which not only means higher temper- atures but also more extensive swings of atmospheric pressure. Research at the University of Lille has indicated that when the pres- sure falls below 1006 millibars or rises above 1026 millibars the risk of heart attacks increases by 13 per cent. The study also showed that a drop in temperature of 10C increases the risk of a heart attack by the same percentage (reported at a meeting of the American Heart Association, Dallas, November 1998). According to the UN Environment Protection Agency director, the cost of prema- ture death due to rising numbers of heatwaves is reckoned to be £14 billion a year in the EU and £11 billion in the US. Worldwide the assessment is £50 billion. ● Oceans are the largest carbon sink. As they warm they are becom- ing less efficient at absorbing CO2. The latest prediction is that the carbon absorption capacity of oceans will decline by 50 per cent as sea temperatures rise. ● Methane emissions from natural wetlands and rice paddy fields are increasing as temperatures rise. To repeat, methane is a much more potent greenhouse gas than CO2 and levels are rising rapidly. ● The year 2000 saw an unprecedented catalogue of warnings. The warming that is eroding Europe’s largest glacier in Iceland also cre- ated clear water across the North West Passage at the top of Canada making navigation possible. This has not happened since prehistoric interglacial warming. Finally, the assumption generally held by policy makers is that a steady rise in CO2 concentrations will produce an equally steady rise in tempera- ture. The evidence from ice cores reveals that the planet has sometimes swung dramatically between extremes of climate in a relatively short time due to powerful feedback that tips the system into a dramatically different steady state. Scientists meeting for a workshop in Berlin in 2003 con- cluded, on the evidence of climate changes to date, that the planet could be on the verge of ‘abrupt, nasty and irreversible’ change (Bill Clark, Harvard University, quoted in New Scientist, 22 November 2003). CLIMATE CHANGE – NATURE OR HUMAN NATURE? 11
- 33. 12 Chapter Two Predictions There is considerable scientific research effort being targeted on the likely consequences of climate change particularly within the scenario that the industrialised nations will continue indefinitely with ‘busi- ness as usual’ (BaU). This BaU scenario assumes some changes and improvements in efficiency in technology. Here are some of the predictions. ● Historic sea levels are well recorded in the Bahamas and Bermuda because these islands have not been subject to tectonic rise and fall. Ancient shorelines show that, at its extreme, sea level was 20 m (70 ft) above the present level during an interglacial period 400 000 years ago. This would occur if all the world’s vast ice sheets disinte- grated. There is a serious risk of this happening to the West Antarctic and Greenland ice sheets and their loss would mean a 12 m rise in sea level (Geology, vol. 27, p. 375). ● In 2001 Antarctic scientists indicated that sea levels could rise by 6 m (20 ft) within 25 years (Reuters). Ultimately, ‘when Antarctica melts it [sea level] will be another 110 metres’ (Sir David King, The Guardian, 14 July 2004). ● Many millions of people live below one metre above sea level. For example, Singapore and its reclaimed territories will be at risk if the sea level rises above 20 cm. The Thames barrage is already deemed to be inadequate. Hamburg is 120 kilometres from the sea but could be inundated. The mean high tidal water level has increased between 40 and 50 cm since the 1970s. ● The condition of the Greenland ice cap is another cause for con- cern. According to one scenario ‘warming of less than 3C – likely in that part of the Arctic within a couple of decades – could start a run- away melting that will eventually raise sea levels worldwide by seven metres’ (New Scientist, ‘Doomsday Scenario’, words attrib- uted to Jonathan Gregory of the Hadley Centre, 22 November 2003). According to a BBC report (28 July 2004) the Greenland ice sheet is melting ten times faster than previously thought. Since May 2004 the ice thickness has reduced by 2–3 m. The same report stated that Alaska is 8C warmer than 30 years ago.
- 34. PREDICTIONS 13 Figure 2.1 Land below 5 metre and 10 metre contours ● In the UK rising sea levels threaten 10 000 hectares of mudflats and salt marshes. But the most serious threat is to 50 per cent of England’s grade 1 agricultural land which lies below the 5 m con- tour (Figure 2.1). Salination following storm surges will render this land sterile. The University of East Anglia Environmental Risk Unit predicts that the 1 in 100 year storm and related floods will show a return rate by 2030 for: Milford Haven 3.5 yrs Cardiff 5 yrs Portland 5 yrs Newhaven 3 yrs Colchester 4 yrs ● A report from a committee chaired by the UK’s Chief Government Scientist, Sir David King, predicts that global warming, coastal ero- sion and the practice of building on flood plains will increasingly raise the level of risk of loss of life and extensive property damage. The panel of scientists behind the report considered four scenarios. The two worst case scenarios more or less correspond to the IPCC Land below 5m AOD Land between 5 and 10m AOD Lowestoft Colchester Sheerness Newhaven
- 35. ARCHITECTURE IN A CLIMATE OF CHANGE 14 Business as Usual scenario in which there is unrestricted economic development and hardly any constraints on pollution. The report concludes that the population at risk from coastal erosion and flooding could increase from 1.6 million today to 3.6 million by the 2080s. The cost to the economy could be £27 billion per year (Future Flooding, a report from the Flood and Coastal Defence Project of the Foresight Programme, April 2004) (Figure 2.2). In an interview with The Guardian (14 July 2004) Sir David King stated: You might think it is not wise, since we are melting ice so fast, to have built our big cities on the edge of the sea where it is now obvious they cannot remain. On current trends, cities like London, New York and New Orleans will be among the first to go. He went on: ‘I am sure that climate change is the biggest problem that civili- sation has had to face in 5000 years’ which gives added weight to his pronouncement in January 2004 that climate change poses a greater threat than international terrorism. ● It was stated earlier that the geological record over 300 million years shows considerable climate swings every 1–2000 years until 8000 years ago, since which time the swings have been much more moderate. The danger is that increasing atmospheric carbon up to treble the pre-industrial level will trigger a return to this pattern. The IPCC Scientific Committee believes that the absolute limit of Figure 2.2 Areas in England and Wales at risk of flooding by 2080 under worst case scenario (from the Office of Science and Technology Foresight Report, Future Flooding, April 2004)
- 36. PREDICTIONS 15 accumulation of atmospheric carbon should be fixed at double the pre-industrial level at around 500 parts per million by volume (ppmv). Even this will have dramatic climate consequences. ● The paleoclimate record shows that generally cooling occurred at a slow rate, but that warming was rapid as stated earlier, for example 12C in a lifetime. ● Global warming poses a serious threat to health. Pests and pathogens are migrating to temperate latitudes. It is already widely understood that illnesses like vector borne malaria and Leishmaniasis (affecting the liver and spleen) are predicted to spread to northern Europe. The UK Department of Health predicts that, by 2020, seasonal malaria will have a firm foothold in southern Britain, including the deadly plasmodium falciparum strain which kills around one million children a year in Africa (Figure 2.3). The incidence of the fatal disease West Nile fever has increased in warm temperate zones. New York had an outbreak in 1999. The Department also estimated that there will be around 3000 deaths a year from heatstroke – a prediction seriously understated if the summer of 2003 sets the pace of change. Higher temperatures would also increase the incidence of food poisoning by 10 000 (Department of Health review of the effects of climate change on the nation’s health, 9 February 2001). ● A warmer atmosphere means greater evaporation with a conse- quent increase in cloud cover. IPCC scientists consider that the net Figure 2.3 Predicted spread of seasonal malaria in Britain by 2020
- 37. effect will be to increase global warming. Water vapour is a potent greenhouse gas. ● Historically relatively abrupt changes in climate have been triggered by vegetation. For example, average temperature rose by 5C in 10 years 14 000 years ago. Earlier it was said that the paleoclimate record shows that in the past the explosive growth of vegetation absorbed massive amounts of atmospheric carbon resulting in a severe weakening of the greenhouse effect and a consequent ice age. Nature could still be the deciding factor. The Hadley Centre forecasts that global warming will cause forests to grow faster over the next 50 years, absorbing more than 100 billion tonnes of carbon. However, from about 2050 the increasing warming will kill many of the forests, thus returning 77 gigatonnes (billion) of carbon to the atmosphere. This will bring a high risk of runaway global warming. Already there is evidence of changes in growth patterns in the Amazon rainforest. Taller, faster growing trees are taking over from the slower growing trees of the understorey of the forest. This is attributed to the higher levels of CO2 in the atmosphere. In the short term this could mean a net loss in the carbon fixing capacity of the forest since the under- storey trees are slower growing and denser in carbon content. Canopy trees are faster growing and lower in carbon content. In the longer term the latter trees are likely to be more susceptible to die-back through heat and drought (New Scientist, p. 12, 13 March 2004). ● A report from the Calicut University, Kerala, by British, Indian and Nepalese researchers predicts that the great rivers of northern India and Pakistan will flow strongly for about 40 years causing wide- spread flooding. After this date most of the glaciers will have disap- peared creating dire problems for populations reliant on rivers fed by melt ice like the Indus and Ganges. It is estimated that all the glaciers in the central and eastern Himalayas will disappear by 2035. Melting glaciers in the Andes and Rocky Mountains will cause similar problems in the Americas (New Scientist, p. 7, 8 May 2004). ● Another danger is posed by the rapid accumulation of meltwater lakes. Meltwater is held back by the mound of debris marking the earlier extremity of the glacier path. These mounds are unstable and periodically collapse with devastating results. It is predicted that the largest of these lakes in the Sagarmatha National Park in Nepal currently holding 30 million cubic metres of water will break out within five years (New Scientist, p. 18, 5 June 1999). The world- wide melting of glaciers and ice caps will contribute 33 per cent of the predicted sea level rise (IPCC). ● The head of research at Munich Re, the world’s largest reinsurance group, predicts that claims within the decade 2040–2050 will have totalled £2000 billion based on the IPCC estimates of the rise in atmospheric carbon. He states: ‘There is reason to fear that climatic changes in nearly all regions of the Earth will lead to natural catastrophes of hitherto unknown force and frequency. Some regions ARCHITECTURE IN A CLIMATE OF CHANGE 16
- 38. will soon become uninsurable’ (quoted in The Guardian, 3 February 2001). ● We have to add to these natural events the prediction that there will be a substantial increase in world population, mostly in areas which can least accommodate it. At present the greatest concentrations of population are in coastal regions which will be devastated if sea level rise predictions are fulfilled. The UN Population Division estimates that the world figure will reach 8.9 billion by 2050. The US Census Bureau predicted in March 2004 that the present popula- tion of 6.2 billion will rise to 9.2 billion by that date. It then believes that the rate of fertility will fall below the replacement level. Even at present 1.3 billion, or one third, of the total world population live in extreme poverty on less than $1 per day. Recent uncertainties An article of 10 July 2004 in New Scientist was headed ‘Peat bogs harbour carbon time bomb’. Research in the University of Wales at Bangor indicates that ‘The world’s peatland stores of carbon are emp- tying at an alarming rate’ (Chris Freeman). Peat bogs store huge quantities of carbon and the evidence is that this is leaching into rivers in the form of dissolved organic carbon (DOC) at the rate of about 6 per cent per year. Bacteria in rivers rapidly convert DOC into CO2 that is released into the atmosphere. Recent research shows that DOC in Welsh rivers has increased 90 per cent since 1988. Freeman predicts that, by the middle of the century, DOC from peat bogs could be as great a source of atmospheric CO2 as the burning of fossil fuels. It appears to be another feedback loop in that an increase in CO2 in the atmosphere is absorbed by vegetation which in turn releases it into the soil moisture. There it feeds bacteria in the water which, in turn, breaks down the peaty soil allowing it to release stored carbon into rivers. Global warming is causing peat bogs to dissolve. The uncertainty with perhaps the greatest potential to derail current predictions about global warming is the role of the clouds, described by New Scientist as ‘the wild card in global warming predic- tions. Add them to climate models and some frightening possibilities fall out’ (Fred Pierce, New Scientist, 24 July 2004). The worry is that global warming will either reduce the global level of cloud cover or change the character of the clouds and their influence on solar radiation. Recent modelling conducted by James Murphy of the Met Office Hadley Centre for Climate Prediction has factored in a range of uncer- tainties in cloud formations such as cloud cover, the lifetime of clouds and their thickness. The model suggested that warming could reach up to 10C on the basis of a doubling of atmospheric CO2 which is widely regarded as inevitable. David Stainforth of Oxford University warns of the possibility of a 12C rise by the end of the century. Cirrus clouds PREDICTIONS 17
- 39. ARCHITECTURE IN A CLIMATE OF CHANGE 18 are the most efficient at reflecting heat back to Earth and these are becoming more prevalent. It is expected that the next range of predic- tions by the IPCC due in 2007 will take account of feedback from cloud cover and produce significantly higher worst case temperature scenar- ios (from New Scientist, 24 July 2004, pp. 45–47). Another cause for concern stems from research finding from the Universities of Sheffield and Bristol. In the Eocene epoch 50 million years ago there was a catastrophic rise in temperature with seas 12C warmer than today. The evidence comes from oxygen trapped in the shells of marine fossils. This leaves a distinct isotope pattern which gives an indi- cation of the sea temperature at a given time. Evidence from plant fos- sils has shown that CO2 levels were similar to the present day and therefore could not have been responsible for that level of warming. It transpires that this was due to emissions of methane, ozone and nitrous oxide, all more powerful greenhouse gases than CO2. At the time the Earth was carpeted with wetlands which produced high levels of methane which led to runaway warming. At the present time it is cattle, rice fields and termites which are major sources of the gas. According to Professor Beerling of Sheffield University: ‘Methane is being produced in increasing amounts thanks to the spread of agriculture in the tropics. Rice is a particularly intensive source. Car exhaust gases and nitrogen fertilisers are also increasing other gases’ (The Observer, 11 July 2004). With a predicted steep rise in emissions from transport over the next decades, the latter point is a serious cause of concern. It is sobering to compare how, according to the UN, different coun- tries are making progress or otherwise in cutting their CO2 emissions. It should be noted that the improvement in the case of Russia is due to the collapse of its heavy industry since 1990 (Figure 2.4). Up to now the focus has been on limiting CO2 emissions almost to the exclusion of other greenhouse gases. It is time to spread the net more widely if there is not to be a rerun of the Eocene catastrophe. Figure 2.4 CO2 emissions by principal nations (UNFCCC 2004) USA European Union Japan China India EU China Russia Japan India 1000 2000 + + + + + 3000 4000 5000 SOURCES: UNFCCC (China figures from IEA) 6000 CO2 EMISSIONS (1,000 MILLION TONNES) 1990 2002 1994 only 0 ++1999+++2001 (both China figures include Hong Kong) United States Russia
- 40. PREDICTIONS 19 What is being done? The core of the problem lies in the disparity between the industrial and developing countries in terms of carbon dioxide emission per head. Despite all the international conventions carbon dioxide emissions from developed countries are showing little sign of abating. The USA at twice the European average is still increasing its emissions which cur- rently stand at 23 per cent of the world’s total. The average citizen in the North American continent is responsible for around 6 tonnes of carbon per year. In Europe it is about 2.8 tonnes per person. Though starting from a very low base, the most rapidly rising per capita emissions are occurring in Southeast Asia, India and China. As a first step on the path of serious CO2 abatement an accord was signed by over 180 countries in 1997 in Kyoto to cut CO2 emissions by 5.2 per cent globally based on 1990 levels. It has to be remembered that the UN IPCC scientists stated that a 60 per cent cut worldwide would be necessary to halt global warming, later endorsed by the UK Royal Commission on Pollution. The US has refused to ratify Kyoto but Russia has signed up which meant that the Treaty came into force in February 2005. The UK was on track to meet its 12.5 per cent reduction target thanks to the gas power programme and the collapse of heavy industry. However, these benefits have now been offset by the growth in emissions from transport. In 2003 there was a 1–2 per cent increase in CO2 emissions. Globally the year 2003 witnessed a significant rise in the level of atmospheric carbon to 3 ppm per year – nearly double the aver- age for the past decade. If aircraft emissions were also taken into account the situation would be substantially worse. One great anomaly is that air travel is excluded from the calcula- tions of CO2. The Parliamentary Environmental Audit Committee (EAC) forecasts that by 2050 air transport will be responsible for two thirds of all UK greenhouse gas emissions. The Department of Transport expects the numbers flying in and out of the UK to rise from 180 million in 2004 to 500 million in 2030 (reported in The Observer, 22 March 2004). Aviation’s share of the UK’s CO2 emissions will have increased four-fold by 2030. At the same time it should be noted that CO2 accounts for only one third of the global warming caused by aircraft (Tom Blundell and Brian Hoskins, members of the Royal Commission on Environmental Pollution, New Scientist, 7 August 2004, p. 24). Even more of a problem faces the USA. Kyoto set its reduction target against the 1990 level at 7 per cent. However, since then it has enjoyed a significant economic boom with a consequent increase in CO2 emissions. To meet the Kyoto requirement it would now have to make a cut of 30 per cent. The only way it would be prepared to consider this kind if target is by carbon trading, not, in itself, an illegiti- mate recourse. However, it all depends on the currency of exchange. The US wants to use trees to balance its carbon books. Planting forests may look attractive but it presents three problems.
- 41. First, there have been attempts to equate the sequestration capac- ity of trees with human activities such as driving cars, so, five trees could soak up the carbon from an average car for one year, or 40 trees counteract the carbon emitted by the average home in five years. Unfortunately there is not a reliable method of accounting for the sequestration capacity of a single tree let alone a forest. Another prob- lem recently exposed in the USA is that forests are inclined to burn down. The last point refers back to the Hadley Centre prediction that there will be accelerating forest growth over the next 50 years, then rapid die-back, releasing massive quantities of carbon into the atmos- phere. Overall, forests could possibly end up huge net contributors to global warming. This seems to have been uppermost in the minds of the European delegates to the conference in The Hague in November 2000 when they refused to sign an agreement which allowed the USA to continue with business as usual in return for planting trees. In the final analysis, if governments and society fail to respond to the imperatives set by climate change, what they cannot escape is the inevitability of dramatic increases in the cost of fossil-based energy as demand increasingly outstrips supply as reserves get ever closer to exhaustion. Market forces are already powering the drive towards renewable energy in some industrialised countries. When you see oil companies investing in renewables then it must be the dawning of the realisation that saving the planet might just be cost effective. The outlook for energy A report published in May 2004 from the European Union called ‘World Energy, Technology and Climate Change Outlook’ offers an insight into a future still dominated by fossil-based energy. It predicts that CO2 emissions will increase by 2.1 per cent per year for the next 30 years whilst energy use will rise by 1.8 per cent. The reason for the difference is that there will be increasing use of coal as oil and gas prices rise and reserves contract. It also estimates a fall in the share of energy from renewables from 13 per cent today to 8 per cent. This is mainly because growth in renewables will not keep pace with overall energy consumption. The report expects that energy use in the US will increase by 50 per cent and in the EU by 18 per cent over the same period. Developing countries, especially China and India, will increase their share of global CO2 emissions from 30 per cent in 1990 to 58 per cent in 2030. China is the world’s second biggest emitter of greenhouse gases and the world’s biggest producer of coal. To meet its expected energy needs China plans to nearly treble its output from coal fired power stations by ARCHITECTURE IN A CLIMATE OF CHANGE 20
- 42. PREDICTIONS 21 2020. These new power plants are not being constructed to accommo- date future CO2 sequestration equipment and they are likely to be in service for 50 years. Oil consumption has doubled in the last 20 years and now stands at 80 million barrels per day, an all time high. So, for decades to come, with cities like Shanghai growing at an exponential rate, China is virtually ruling out measures to mitigate its CO2 emissions, which, as a developing country, it is not required to do. As the economies of the world power ahead on the back of fossil fuels, the spectre of diminishing reserves heightens anxieties within the corridors of government. The oil companies estimate that reserves will be exhausted within about 40 years but that is not so much the prime issue. According to Stephen Lewis, City economic analyst, ‘the kind of growth rates to which oil consuming countries are committed appear to be generating the demand for oil well above the underlying growth in the rate of supply . . . the US, the Middle East, the North Sea . . . all appear to be past their production peaks’ (The Guardian, 9 August 2004). There are conflicting estimates, but petroconsultants who advise the government claim that only one new barrel of oil is discovered for every four that are used. Their estimate is that we are only two years away from the peak of oil production. By 2020 the UK will be importing 80 per cent of its energy based on the current rate of consumption. The histogram in Figure 2.5 indicates the rate of decline of UK reserves of both oil and gas. As regards gas, the major reserves are located within countries that do not have a good record of stability. The North Sea reserves are already diminishing with a Figure 2.5 UK oil and gas reserves to 2020 (Association for the Study of Peak Oil and Gas 2004) 1967 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003 2006 2009 2012 2015 2018 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.5 4.5 5.0 Oil equivalent (mmboe/day) Gas-Possible Oil-Possible Gas-2P Oil-2P Gas Oil Already produced Future production
- 43. life expectancy of 15–20 years. The government has acknowledged that, by 2020, 90 per cent of the UK’s gas will come from Russia, Iran and Nigeria (Ministry of Defence, 8 February 2001). For the US the Department of Energy estimates that imports of oil will rise from 54 per cent in 2004 to 70 per cent by 2025 due to its declining reserves and increasing consumption. Add to this the fact that at least half the remaining global reserves will be located in five autocracies in the Middle East who have already demonstrated their ability to manipulate prices causing the oil shocks of the 1970s. These states account for 35 per cent of the market, the point at which it is considered they are able to control prices at a time of rising demand, especially by developing countries on the rapid road to developed status. According to the environmental policy analyst Dr David Fleming it is ‘not possible that we can survive without a dramatic increase in the price of oil’ (The Guardian, 2 March 2000). The government was warned that another oil price shock could trigger a stock market crash, or even war. In the oil shocks of the 1970s we were extricated from long-term pain by the discovery of large oil reserves in the North Sea and Alaska. This time there are no escape routes. The Kuwait episode then the Iraq war should remind us of the sensitivity of the situation. The world is one huge combustion engine which consumes 74 mil- lion barrels of oil a day to keep it running for now! At the present time in China one person in 125 has a car. The Chinese economy is growing at 8–10 per cent a year. It has joined the World Trade Organisation and opened its markets to international trade which gives additional impe- tus to economic growth. In no time there will be one person in 50 then perhaps one in 20 owning a car. Even without including the prospects for China the current demand for oil worldwide is growing at 2 per cent a year. By 2020 it is estimated that there will be one billion cars on the world’s roads. At the same time petrol geologists estimate that produc- tion of oil will peak in the first decade of 2000 and then output will decline by 3 per cent a year. Oil geologist Colin J. Campbell says we are ‘at the beginning of the end of the age of oil’. He predicts that after 2005 there will be serious shortages of supply with steeply rising prices and by 2010 a major oil shock reminiscent of the 1970s except that then there were huge reserves to be tapped. There are still large reserves but they are located in places like the states around the Caspian basin which Russia regards as its sphere of influence – not much comfort to the west, in particular the UK, where it is expected that its North Sea fields will be exhausted by 2016. An updated 2004 scenario for world peak oil production by Colin Campbell shows, in a graph published on the website of the Association for the Study of Peak Oil (ASPO), that both gas and oil worldwide will peak around 2008 (Figure 2.6). Beyond 2008, increasing price volatility for both oil and gas seems inevitable. ARCHITECTURE IN A CLIMATE OF CHANGE 22
- 44. PREDICTIONS 23 The nuclear option The UK has problems regarding its nuclear capacity. Recently questions have been raised about the government’s estimates of future genera- tion capacity within the nuclear industry. Environment Data Services have described them as ‘heroically optimistic’, a verdict which therefore also applies to the government’s target of 20 per cent reduction in CO2 emissions by 2010 since that target assumes full bore production by its ageing reactors. In fact nuclear output dropped 4 per cent in 1999 and 10 per cent in 2000 and in the latter year coal fired generation was up 13 per cent. All but two of the Magnox stations have closure dates before 2008. The pressurised water and gas cooled reactors have been beset with problems. By 2014 75 per cent of nuclear will have been decommissioned. The DTI’s energy predictions assume that, for the next decade, the creaking nuclear industry will operate at full capacity with an unprecedented rate of efficiency. After that, renewables, gas generation and possibly a new batch of nuclear generators will fill the vacuum. As we have noted gas has its uncertainties. The projected fuel mix for the UK in 2010 is: ● Coal 16 per cent ● Nuclear 16 per cent ● Renewables 10 per cent ● Gas 57 per cent. However, in 2008 the EU will enforce desulphurisation regulations on coal fired plants making them uneconomic. Their only option will be to switch to biofuels such as rapid rotation crops which is already being pioneered at the massive Drax power station in Yorkshire. The use of biofuels may offer a future for coal fired power stations. A plant Figure 2.6 World oil and gas production to 2050 1930 1940 1950 1980 1970 1980 1990 2000 2010 2020 2030 2040 2050 0 5 10 15 20 25 30 35 Billion barrels a year (Gb/a) Russia US-48 Europe Russia Other M.East Heavy etc. Deepwater Polar NGL
- 45. ARCHITECTURE IN A CLIMATE OF CHANGE 24 operated by Biojoule in East Anglia is already producing 15 000 tonnes a year of specially processed wood for partial fuel replacement in coal fired power plants. The obvious conclusion to draw from all this is that buildings being designed now will, in most cases, still be functioning when the screws on fossil fuels are really tightening. For buildings wholly reliant on fossil-based energy, it will be impossible to make accurate predictions as to running costs in, say, ten years’ time. What is certain is that energy prices will rise steeply since there is still only patchy evidence of the will to stave off this crisis by the deployment of renewable energy tech- nologies. The pressure to incorporate the external costs like damage to health, buildings and above all the biosphere into the price of fossil will intensify as the effects of global warming become increasingly threat- ening. The government undertaking is to meet 10 per cent of electric- ity demand by 2010 from renewable sources. What tends to be overlooked is that, by then, demand will probably have increased by more than this percentage and, at the same time, many of the nuclear power plants are likely to have been decommissioned. By 2015 the UK could be facing an energy vacuum which emphasises the need to take the plunge into renewable technologies as a matter of urgency, which makes the latest offering from the European Environment Agency (EEA) report of 2004 all the more remarkable and disturbing. It states that within the European Union the share of renewable electricity rose from 12 per cent in 1990 to 14 per cent in 2001. The EU target is 21 per cent Figure 2.7 Comparison of electricity derived from renewables in 25 EU states (source: European Environment Agency 2004) Indicative targets All other renewables Industrial and municipal waste Large hydropower 80 70 60 50 40 30 20 10 0 Renewables as share of electricity consumption (%) A u s t r i a S w e d e n L a t v i a P o r t u g a l S l o v e n i a F i n l a n d S p a i n S l o v a k R e p u b l i c D e n m a r k I t a l y F r a n c e E U - 2 5 G e r m a n y G r e e c e I r e l a n d N e t h e r l a n d s C z e c h R e p u b l i c L u x u e m b o u r g L i t h u a n i a U n i t e d K i n g d o m P o l a n d B e l g i u m H u n g a r y E s t o n i a C y p r u s M a l t a
- 46. by 2010, suggesting that much more needs to be done. The EEA has produced a histogram which shows the relative performance of mem- ber states. The UK is fourth from bottom of the table of all countries which have a contribution from renewables. (Figure 2.7) (EEA 2004; Signals 2004, a European Environment Agency Update on selected issues, Copenhagen, May 2004). PREDICTIONS 25
- 47. 26 Chapter Three Renewable technologies – the marine environment Two quotes set the scene for this chapter: A sustainable energy system is probably the single most important milestone in our efforts to create a sustainable future . . . Decarbonisation of the energy system is task number one. Oystein Dahle, Chairman. Worldwatch Institute and Global civilisation can only escape the life-threatening fossil-fuel resource trap if every effort is made to bring about an immediate transition to renewable and environmentally sustainable resources and thereby end the dependence on fossil fuels. Hermann Scheer, The Solar Economy, Earthscan 2002, p. 7 The UK energy picture In 2002 total inland energy consumption in the UK was 229.6 million tonnes of oil equivalent (mtoe). Nuclear contributed 21.3 mtoe to the total. Renewables and energy from waste accounted for a mere 2.7 mtoe (UK Energy in Brief, DTI, July 2003). Is it fantasy to support that renewable energy sources could equal, even exceed, this capacity without help from nuclear? This is a key question since the Energy White Paper of February 2002 put nuclear on hold pending a demon- stration that renewables could fill the void left by the decommissioning of the present cluster of nuclear facilities. The government has declared a target of 10.4 per cent for renew- ables by 2010 and an aspiration to achieve 20 per cent by 2020. The 20 per cent figure is significant since it represents the limit at which the present structure of the grid can accommodate small-scale and intermittent
- 48. RENEWABLE TECHNOLOGIES – THE MARINE ENVIRONMENT 27 suppliers. Beyond this percentage the grid would have to be reconfigured to encompass extensive distributed generation, as recommended by the Royal Commission on Environmental Pollution (ibid., p. xi). As far as the major power distributors are concerned, the 20 per cent threshold may well be regarded as the ‘red line’ beyond which they will be forced to run on less than full capacity, at the same time compensating for fluctuations in the supply from renewables. According to Hermann Scheer this would threaten the long-term ambitions of the power industry which sees the prospect of ultimately controlling information transmission as well as energy. ‘They hold all the cards they need to construct a compre- hensive commodity supply and media empire’ (ibid., p. 60). One of the key factors favouring the big suppliers is the web of direct and indirect subsidies which the industry enjoys such as the fact that its raw material is regarded as being a free gift from nature. Only now is it being widely realised that reserves, apart from coal, will be exhausted sooner rather than later. At the same time the market pays scant regard to its environmen- tal responsibilities, especially that of driving up global warming. The European Commission’s ExternE project has sought to quantify the externalities. For example, it concludes that the real cost of electricity from coal and oil is about double the current economic cost to the pro- ducers. For gas generated electricity the shortfall is about 30 per cent. The New Elements for the Assessment of External Costs from Energy (NewExt) is refining the methodology to provide more accurate infor- mation and was due to report in 2004. The results should make it possi- ble more accurately to calculate life-cycle environmental costs. Government claims that energy suppliers operate within the framework of a free market and on a level playing field is based on flawed economics. The anomaly is that the cost–benefit system employed here ignores the element of risk. For some reason energy is not subjected to the normal rules of financial risk assessment in deter- mining the market value of the commodity. Never has it been more apparent that oil and gas are high risk commodities that can have a powerful negative impact on the Stock Index due to price volatility. In contrast, renewables, being relatively high capital cost but low running cost technologies, are not nearly so affected by macro- economic shifts such as the international price of oil or the Stock Index. Repayment of capital and operating costs are largely fixed and so represent a low risk. The problem is that renewables with their high investment costs violate one of the founding laws of accountancy that investors want a high return on capital in the short term. This is the market situation in which renewables have to compete and it constitutes a sharply tilted playing field in favour of the fossil fuel industries. We have the bizarre situation that a highly subsidised, highly polluting, high risk energy stream is stifling the almost zero risk renewable systems that draw on solar and lunar energy and are therefore not reliant on a continual input of an extracted fuel. This is clearly an abuse of the
- 49. ARCHITECTURE IN A CLIMATE OF CHANGE 28 term ‘free market’. If the contours of the energy playing field really were level, then renewables would offer excellent investment opportunities. Since it seems inevitable that renewables will have to fight their corner in a free market for an indefinite period, then these anomalies must be corrected if a decarbonised electricity infrastructure is to be a reality. Energy from rivers and seas Energy extracted from the marine environment is, on the one hand, the most capital intensive form of energy, but, on the other, offers the longest-term energy certainty coupled with the highest energy density. Energy can be derived from water according to four basic princi- ples: first, hydroelectricity from the damming of rivers; second, from hydrodynamics or the movement of water by virtue of tidal rise and fall, tidal currents and waves; third, the dynamics of thermal difference; and fourth, the extraction of hydrogen from water via electrolysis. This chapter focuses on the first and second technologies. Hydroelectric generation Hydroelectric schemes which exploit height difference in the flow path of water are the oldest method of generation from water. It involves damming a watercourse to create the necessary pressure to drive high speed impulse turbines. The Boulder Dam scheme in the USA was the first large-scale project implemented in the 1930s as a means of driving the country out of recession. One of the first major projects to be completed after the Second World War was the Aswan Dam scheme initiated by Colonel Nasser, the Egyptian President. Work started in 1960 to create the huge Lake Nasser as the storage facility and as a potential irrigation source for a major part of the country. It cost $1 billion ($10 billion at current prices) and began operations in 1968, delivering 2000 megawatts (MW) of power. The project has served to illustrate some of the problems which accompany hydroelectric schemes of this massive scale. For example, evaporation from the lake has been much greater than anticipated, and the country is considering reactivating storage schemes beyond its borders. At the same time, the dam has so disrupted the flow of the Nile that it threatens the agriculture of the delta. A further problem is that, historically, the Nile has conveyed millions of tonnes of silt per year, mostly soil, from the Ethiopian high- lands. The silt, part of which used to be deposited in the Nile flood plain, is now trapped behind the dam, a fact which is calculated to have done irreparable damage to the fertility of the Nile valley and delta. To compensate for the loss Egypt is now one of world’s heaviest users of agricultural chemicals.
- 50. RENEWABLE TECHNOLOGIES – THE MARINE ENVIRONMENT 29 One of the worst drawbacks concerns saline pollution. Salts are dissolved in river water and modern irrigation systems leave salts behind – about one tonne per hectare. Large areas of fertile land are being threatened by the salt which makes the ground toxic to plants and ultimately causes it to revert to desert. There is now a project to remove saline water from two million hectares of land at a cost which exceeds the original price of the dam (New Scientist, pp. 28–32, 7 May 1994). In December 1994 work commenced on the Three Gorges scheme on the Yangtze River. The dam is two kilometres long and some 100 metres high. It has created a lake 600 kilometres long displacing over one million people. In return the country will receive 18 000 MW of power which is 50 per cent more than the world’s existing largest dam, the Itaipu Dam in Paraguay. Even so, in the long term this dam will make a relatively small impact on China’s dependency on fossil fuel. In addi- tion, in November 1994, plans were revived to generate up to 37 000 MW along the course of Mekong River, again with drastic potential social consequences. With the exception of projects on the River Danube, Europe gains most of its hydroelectricity from medium to small-scale plants. Most of Norway’s supply is from hydro sources; in Sweden it is 50 per cent of the total and Scotland produces 60 per cent of its electricity from non-fossil sources, mostly hydro. According to the Department of Trade and Industry, ‘The UK has a considerable untapped small-scale hydro resource’ such as the discreet plant at Garnedd in Gwynedd, North Wales. Given the right buying-in rates from the National Grid, such ven- tures could become a highly commercial proposition. Small-scale hydro In small-scale projects water is usually contained at high level by a dam or weir and led down a pipe (penstock) or channel to a generator about 50 m below to create the necessary force to drive the generator. An intermediate technology version has been designed for developing countries in which a standard pump is converted to a turbine and an electric motor to a generator (New Scientist, p. 29, 29 June 1991) (further information in Smith, P.F. (2002) ‘Small-scale hydro,’ in Sustainability at the Cutting Edge, Ch. 10, Architectural Press). ‘Run of river’ systems Many rivers have a flow rate in excess of 0.75 m per second which makes them eligible to power so-called run of river generators. The conventional method is to create a dedicated channel which
- 51. ARCHITECTURE IN A CLIMATE OF CHANGE 30 accommodates a cross-flow generator which is a modern version of a water wheel or a ‘Kaplan’ turbine which has variable blades. A Norwegian company, Water Power Industries (WPI), has devel- oped a water turbine on floats that has a vertical axis rotor fitted with blades shaped like an aircraft wing. The ‘waterfoils’ are vertical and the flow of a river creates negative pressure which causes the wheel to rotate (Figure 3.1). The wings are continuously adjusted by computer monitoring to keep them at their most efficient angle. It is claimed that the water turbine converts 50 per cent of the energy in the water to electricity with a theoretical maximum of 59 per cent. Assuming a steady flow of water with a velocity of 3 m/s and a regu- larity of 96 per cent a 15 m diameter 500 kW turbine would produce 4 million kWh/year. Not only could this system capture the energy of many rivers, it could also be situated in channels with a high tidal flow which are too shallow for other types of tidal turbine. Tidal energy Tidal energy is predictable to the minute for at least the rest of the century. Tide levels can be affected by storm surges as experienced dramatically in the UK in 1953. The British Isles benefit from some of the Figure 3.1 WPI turbine (courtesy of CADDET, issue 1/04)
- 52. RENEWABLE TECHNOLOGIES – THE MARINE ENVIRONMENT 31 greatest tidal ranges in Europe. In summary, there are at least four technologies that can exploit the action of the tides, offering reliable electricity in the multi-gigawatt range. They are: ● The tidal barrage ● The tidal fence or bridge ● Tidal mills or rotors ● Impoundment. The tidal barrage Trapping water at high tide and releasing it when there is an adequate head is an ancient technology. A medieval tide mill is still in working order in Woodbridge, Suffolk. In the first quarter of the twentieth cen- tury this principle was applied to electricity generation in the feasibility studies for a barrage across the River Severn. Tidal power works on the principle that water is held back on the ebb tide to provide a sufficient head of water to rotate a turbine. Dual generation is possible if the flow tide is also exploited. A Royal Commission was formed in 1925 to report on the potential of the River Severn to produce energy at a competitive price. It reported in 1933 that the scheme was viable. Since then the technology has improved including a doubling of the size of generators. This increases the volume of water passing through the barrage by the square. A further study was completed in 1945 and the latest in-depth investigation was concluded in 1981. In all cases the verdict was posi- tive, though the last report was cautious about the cost/benefit profile of the scheme in the context of nuclear energy. Despite this supporting evidence the UK still shows reluctance to exploit this source of power. Recently a discussion document produced by the Institution of Civil Engineers stated in respect of tidal energy: it appears illogical that so potentially abundant an option will be deferred perpetually when the unit power costings involved are estimated to be reasonably competitive with all alternatives except combined cycle gas turbines. Power generation is obviously intermittent but the spread of tide times around the coasts helps to even out the contribution to the grid. The only operational barrage in Europe is at La Rance, Normandy. It is a bidirectional scheme, that is, it generates on both the flow and ebb tides. Two-way operation is only beneficial where there is a consid- erable tidal range and even then only during spring tides. Annual production at La Rance is about 610 gigawatt hours (GWh). Despite its success as a demonstration project, the French government elected to concentrate its generation policy on nuclear power which accounts for about 75 per cent of its capacity.
- 53. ARCHITECTURE IN A CLIMATE OF CHANGE 32 Up to now, schemes proposed in the UK have been one direc- tional, generating only on the ebb tide. The principle is that water is held upstream at high tide until the downstream level has fallen by at least 2.0 metres. The upstream volume of water is supplemented by pumping additional water from downstream on the flood tide. This is reckoned to be more cost effective than bidirectional generation in most situations (Figure 3.2). The technology of barrages was transformed by the caisson tech- niques employed in the construction of the Mulberry Harbour floated into place after D-Day in the Second World War. It is a modular tech- nique with turbine caissons constructed on slipways or temporary sand islands. According to the Department of Trade and Industry’s Energy Paper Number 60, November 1992: ‘The UK has probably the most favourable conditions in Europe for generating electricity from the tides.’ In fact, it has about half of all the European Union’s tidal generating potential of approximately 105 terawatt hours per year (TWh/y) (ETSU). The DTI report concludes: There are several advantages arising from the construction of tidal barrages in addition to providing a clean, non-polluting source of energy. Tidal barrages can assist with the local infrastructure of the region, create regional development Figure 3.2 Basic tidal barrage
- 54. RENEWABLE TECHNOLOGIES – THE MARINE ENVIRONMENT 33 opportunities and provide protection against local flooding within the basin during storm surge. Around the world numerous opportunities exist to exploit tidal energy, notably in the Bay of Fundy in Canada where there is a proposal to generate 6400 MW. China has 500 possible sites with a total capacity of 110 000 MW. Professor Eric Wilson, a leading tidal expert in the UK, sums up the situation by saying that a tidal power scheme may be expensive to build, but it is cheap to run. ‘After a time, it is a gold mine.’ In 1994 the government decided to abandon further research into tidal barrages for a variety of reasons ranging from the ecological to the economic. In market terms a normal market discount rate heavily penalises a high capital cost, long life, low running cost technology. The economic argument could be countered if the market corrections stated earlier were to be implemented. However, another concern has grown in stature, namely, the threat from rising sea level amplified by an accelerating rate of storm surges. Following the 1953 floods, it was decided that London should be protected by a barrage. It was designed in the 1970s to last until 2030. However, the threat from rising sea level was hardly a factor in the 1970s; now it is a major cause of concern that the barrage will be over- whelmed by a combination of rising sea level, storm surges and increased rainfall and river rundown well before that date. In the year 1986/87 the barrage was not closed once against tidal and river flood- ing; in 2001 it closed 24 times. A further complication is the Thames Gateway project which includes 120 000 new homes below sea level. If one flood breaks through the Thames Barrier it will cost about £30 bil- lion or roughly 2 per cent of GDP (Sir David King, Government Chief Scientist, The Guardian, 9 January 2004). All this combines to make a strong case for an estuary barrage that will protect both the Thames and the Medway and, at the same time, generate multi-gigawatt power for the capital (Figure 3.3). One of the arguments against tidal barrages is that they would trap pollution upstream. Since rivers are now appreciably cleaner than in the 1970s, thanks largely to EU Directives, this should not now be a factor. The Thames is claimed to be the cleanest river in Europe, playing host to salmon and other desirable fish species. A group of engineering companies has renewed the argument in favour of the River Severn bar- rage, indicating that it would meet 6 per cent of Britain’s electricity needs whilst protecting the estuary’s coastline from flooding (New Scientist, 25 January 2003). The tidal fence There is, however, an alternative to a barrage which can also deliver massive amounts of energy at less cost/kWh, namely, the tidal fence or
- 55. Other documents randomly have different content
- 56. Finding but little satisfaction in what had been attempted on this subject by Borellus and others, I endeavoured, about twenty-five years since, by proper experiments, to find what was the real force of the blood in the crural arteries of dogs, and about six years afterwards I repeated the like experiments on two horses, and a fallow doe; but did not then pursue the matter any further, being discouraged by the disagreeableness of anatomical dissections. But having of late years found by experience the advantage of making use of the statical way of investigation, not only in our researches into the nature of vegetables, but also in the chymical analysis of the air, I was induced to hope for some success, if the same method of enquiry were applied to animal bodies.... Having laid open the left crural artery (of a mare), I inserted into it a brass pipe whose bore was 1/6 of an inch in diameter; and to that, by means of another brass pipe which was fitly adapted to it, I fixed a glass tube of nearly the same diameter, which was 9 feet in length; then, untying the ligature on the artery, the blood rose in the tube 8 feet 3 inches perpendicular above the level of the left ventricle of the heart, but it did not attain to its full height at once: it rushed up gradually at each pulse 12, 8, 6, 4, 2, and sometimes 1 inch. When it was at its full height, it would rise and fall at and after each pulse 2, 3, or 4 inches, and sometimes it would fall 12 or 14 inches, and have there for a time the same vibrations up and down, at and after each pulse, as it had when it was at its full height, to which it would rise again, after forty or fifty pulses. 3. The Collateral Circulation After Hales, came John Hunter, who was five years old when the Statical Essays were published. His experiments on the blood were
- 57. mostly concerned with its properties, not with its course; but one great experiment must be noted here that puts him in line with Harvey, Malpighi, and Hales. He got from it his knowledge of the collateral circulation; he learned how the obstruction of an artery is followed by enlargement of the vessels in its neighbourhood, so that the parts beyond the obstruction do not suffer from want of blood: and the facts of collateral circulation were fresh in his mind when, a few months later, he conceived and performed his operation for aneurysm (December 1785). The old operation gave him no help here; and Anel's operation was but a single instance, and no sure guide for Hunter, because Anel's patient had a different sort of aneurysm. Hunter knew that the collateral circulation could be trusted to nourish the limb, if the femoral artery were ligatured in Hunter's canal for the cure of popliteal aneurysm; and he got this knowledge from the experiment that he had made on one of the deer in Richmond Park, to see the influence of ligature of the carotid artery on the growth of the antler. The following account of this experiment was given by Sir Richard Owen, who had it from Mr. Clift, Hunter's devoted pupil and friend:— In the month of July, when the bucks' antlers were half- grown, he caused one of them to be caught and thrown; and, knowing the arterial supply to the hot 'velvet,' as the keepers call it, Hunter cut down upon and tied the external carotid; upon which, laying his hand upon the antler, he found that the pulsations of the arterial channels stopped, and the surface soon grew cold. The buck was released, and Hunter speculated on the result— whether the antler, arrested at mid-growth, would be shed like the full-grown one, or be longer retained. A week or so afterward he drove down again to the park, and caused the buck to be caught and thrown. The wound was healed about the ligature; but on laying his hand on the antler, he found to his surprise that the warmth had returned, and the channels of supply to the velvety formative covering were again pulsating. His first
- 58. impression was that his operation had been defective. To test this, he had the buck killed and sent to Leicester Square. The arterial system was injected. Hunter found that the external carotid had been duly tied. But certain small branches, coming off on the proximal or heart's side of the ligature, had enlarged; and, tracing-on these, he found that they had anastomosed with other small branches from the distal continuation of the carotid, and these new channels had restored the supply to the growing antler.... Here was a consequence of his experiment he had not at all foreseen or expected. A new property of the living arteries was unfolded to him. All the anatomists had overlooked this physiological change in the living body, brought about by disease. And the surgeons, since anatomy could not help them, had been driven by the mortality of the old operation to the practice of amputation. 4. The Mercurial Manometer Hale's experiments on the blood-pressure were admirable in their time; but neither he nor his successors could take into account all the physiological and mathematical facts of the case. But a great advance was made in 1828, when Poiseuille published his thesis, Sur la Force du Cœur Aortique, with a description of the mercurial manometer. Poiseuille had begun with the received idea that the blood-pressure in the arteries would vary according to the distance from the heart, but he found by experiment that this doctrine was wrong:— At my first experiments, wishing to make sure whether the opinions, given à priori, were true, I observed to my great astonishment that two tubes, applied at the same time to two arteries at different distances from the heart, gave columns of exactly the same height, and not, as I had expected, of different heights. This made the work
- 59. very much simpler, because, to whatever artery I applied the instrument, I obtained the same results that I should have got by placing it on the ascending aorta itself. He found also, by experiments, that the coagulation of the blood in the tube could be prevented by filling one part of the tube with a saturated solution of sodium carbonate. The tube, thus prepared, was connected with the artery by a fine cannula, exactly fitting the artery. With this instrument, Poiseuille was able to obtain results far more accurate than those of Hales, and to observe the diverse influences of the respiratory movements on the blood-pressure. He sums up his results in these words:— I come to this irrevocable conclusion, that the force with which a molecule of blood moves, whether in the carotid, or in the aorta, etc., is exactly equal to the force which moves a molecule in the smallest arterial branch; or, in other words, that a molecule of blood moves with the same force over the whole course of the arterial system— which, à priori, with all the physiologists, I was far from thinking. And he adds, in a footnote:— When I say that this force is the same over the whole course of the arterial system, I do not mean to deny that it must needs be modified at certain points of this system, which present a special arrangement, such as the anastomosing arches of the mesentery, the arterial circle of Willis, etc. Later, in 1835, he published a very valuable memoir on the movement of the blood in the capillaries under different conditions of heat, cold, and atmospheric pressure. 5. The Registration of the Blood-pressure
- 60. Poiseuille's work, in its turn, was left behind as physiology went forward: especially, the discovery of the vaso-motor nerves compelled physiologists to reconsider the whole subject of the blood-pressure. If Poiseuille's thesis (1828) be compared with Marey's book (1863), Physiologie Médicale de la Circulation du Sang, it will be evident at once how much wider and deeper the problem had become. Poiseuille's thesis is chiefly concerned with mathematics and hydrostatics; it suggests no method of immediate permanent registration of the pulse, and is of no great value to practical medicine: Marey's book, by its very title, shows what a long advance had been made between 1828 and 1863—Physiologie Médicale de la Circulation du Sang, basée sur l'étude graphique des mouvements du cœur et du pouls artériel, avec application aux maladies de l'appareil circulatoire. Though the contrast is great between Hales' may-pole and Poiseuille's manometer, there is even a greater contrast between Poiseuille's mathematical calculations and Marey's practical use of the sphygmograph for the study of the blood-pressure in health and disease. Marey had the happiness of seeing medicine, physiology, and physics, all three of them working to one end:— La circulation du sang est un des sujets pour lesquels la médecine a le plus besoin de s'éclairer de la physiologie, et où celle-ci à son tour tire le plus de lumière des sciences physiques. Ces dernières années sont marquées par deux grands progrès qui ouvrent aux recherches à venir des horizons nouveaux: en Allemagne, l'introduction des procédés graphiques dans l'étude du mouvement du sang; en France, la démonstration de l'influence du système nerveux sur la circulation périphérique. Cette dernière découverte, que nous devons à M. Cl. Bernard, et qui depuis dix ans a donné tant d'impulsion à la science, montre mieux que toute autre combien la physiologie est indispensable à la médecine, tandis que les travaux allemands ont bien fait ressortir l'importance des connaissances physiques dans les études médicales.
- 61. Marey's sphygmograph was not the first instrument of its kind. There had been, before it, Hérisson's sphygmometer, Ludwig's kymographion, and the sphygmographs of Volckmann, King, and Vierordt. But, if one compares a Vierordt tracing with a Marey tracing, it will be plain that Marey's results were far advanced beyond the useless oscillations isochrones recorded by Vierordt's instrument. Beside this improved sphygmograph, Chauveau and Marey also invented the cardiograph, for the observation of the blood-pressure within the cavities of the heart. Their cardiograph was a set of very delicate elastic tambours, resting on the heart, or passed through fine tubes into the cavities of the heart,[1] and communicating impulses to levers with writing-points. These writing-points, touching a revolving cylinder, recorded the variations of the endocardial pressure, and the duration of the auricular and ventricular contractions. It is impossible here to describe the subsequent study of those more abstruse problems that the older physiologists had not so much as thought of: the minutest variations of the blood-pressure, the multiple influences of the nervous system on the heart and blood- vessels, the relations between blood-pressure and secretion, the automatism of the heart-beat, the influence of gravitation, and other finer and more complex issues of physiology. But, even if one stops at Marey's book, now more than forty years old, there is an abundant record of good work, from the discovery of the circulation to the invention of the sphygmograph. II THE LACTEALS Asellius, in his account of his discovery of the lacteal vessels (1622), is of opinion that certain of the ancients had seen these vessels, but had not recognised them. He has a great reverence for
- 62. authority: Hippocrates, Plato, Aristotle, the Stoics, Herophilus, Galen, Pollux, Rhases, and a host of other names, he quotes them all, and all with profound respect; and comes to this conclusion: It did not escape the ancients, that certain vessels must needs be concerned with containing and carrying the chyle, and certain other vessels with the blood: but the true and very vessels of the chyle, that is, my 'veins,' though they were seen by some of the ancients, yet they were recognised by none of them. He can forgive them all, except Galen, qui videtur nosse omnino debuisse—but, as for Galen, I know not at all what I am to think. For he, who made more than six hundred sections of living animals, as he boasts himself, and so often opened many animals when they were lately fed, are we to think it possible that these veins never showed themselves to him, that he never had them under his eyes, that he never investigated them—he to whom Erasistratus had given so great cause for searching out the whole matter? Probably, the milk-white threads had been taken for nerves by those who had seen them: and those who had never seen them, but believed in their existence, rested their belief on a general idea that the chyle must, somehow, have vessels of its own apart from the blood-vessels. What Galen and Erasistratus must have seen, Asellius and Pecquet discovered: and Harvey gives a careful review of the discovery in his letters to Nardi (May 1652) and to Morison (November 1653). He does not accept it; but the point is that he recognises it as a new thing altogether. A year or two after he had made the discovery, Asellius died; and his work was published in 1627 by two Milanese physicians, and was dedicated by them to the senate of the Academy of Milan, where Asellius had been professor of anatomy. The full title of his book is, De Lactibus sive Lacteis Venis, quarto Vasorum Mesaraicorum genere novo invento, Gasparis Asellii Cremonensis, Anatomici Ticinensis, Dissertatio. Quâ sententiæ anatomicæ multæ vel perperam receptæ convelluntur vel partim perceptæ illustrantur. He gives the following account of the discovery, in the chapter entitled Historia primæ vasorum istorum inventionis cum fide narrata. On 23rd July 1622, demonstrating the movement of the diaphragm in a dog, he
- 63. observed suddenly, as it were, many threads, very thin and very white, dispersed through the whole mesentery and through the intestines, with ramifications almost endless—plurimos, eosque tenuissimos candido-sissimosque ceu funiculos per omne mesenterium et per intestina infinitis propemodum propaginibus dispersos:— Thinking at first sight that they were nerves, I did not greatly heed them. But soon I saw that I was wrong, for I bethought me that the nerves, which belong to the intestines, are distinct from these threads, and very different from them, and have a separate course. Wherefore, struck by the newness of the matter, I stopped for a time silent, while one way and another there came to my mind the controversies that occupy anatomists, as to the mesenteric veins and their use; which controversies are as full of quarrels as of words. When I had pulled myself together, to make experiment, taking a very sharp scalpel, I pierce one of the larger threads. Scarcely had I hit it off, when I see a white fluid running out, like milk or cream. At which sight, when I could not hold my joy, turning to those who were there, first to Alexander Tadinus and Senator Septalius, both of them members of the most honourable College of Physicians, and, at the time of this writing, officers of the public health, 'I have found it,' I say like Archimedes; and therewith invite them to the so pleasant sight of a thing so unwonted; they being agitated, like myself, by the newness of it. He then describes the collapse and disappearance of the vessels at death, and the many experiments which he made for further study of them; and the failure, when he tried to find them in animals not lately fed. He did not trace them beyond the mesentery, and believed that they emptied themselves into the liver. The discovery of their connection with the receptaculum chyli and the thoracic duct
- 64. was made by Jehan Pecquet of Dieppe, Madame de Sévigné's doctor, her good little Pecquet. The full title of his book (2nd ed., 1654) is, Expérimenta Nova Anatomica, quibus incognitum hactenus Receptaculum, et ab eo per Thoracem in ramos usque subclavios Vasa Lactea deteguntur. He has not the academical learning of Asellius, nor his obsequious regard for the ancients; and the discovery of the thoracic duct came, as it were by chance, out of an experiment that was of itself wholly useless. He had killed an animal by removing its heart, and then saw a small quantity of milky fluid coming from the cut end of the vena cava—Albicantem subinde Lactei liquoris, nec certe parum fluidi scaturiginem, intra Venæ Cavæ fistulam, circ[=a] dextri sedem Ventriculi, miror effluere—and found that this fluid was identical with the chyle in the lacteals. In another experiment, he succeeded in finding the thoracic duct—At last, by careful examination deep down along the sides of the dorsal vertebræ, a sort of whiteness, as of a lacteal vessel, catches my eyes. It lay in a sinuous course, close up against the spine. I was in doubt, for all my scrutiny, whether I had to do with a nerve or with a vessel. Therefore, I put a ligature a little below the clavicular veins; and then the flaccidity above the ligature, and the swelling of the distended duct below the ligature, broke down my doubt—Ergo subducto paulo infra Claviculas vinculo, cum a ligaturâ sursum flaccesceret, superstite deorsum turgentis alveoli tumore, dubium meum penitus enervavit.... Laxatis vinculis, lacteus utrinque rivulus in Cavam affatim Chylum profudit. It is to be noted that Asellius and Pecquet, both of them, made their discoveries as it were by chance. Unless digestion were going on, the lacteals would be empty and invisible; and, on the dead body, lacteals, receptaculum, and thoracic duct would all be empty. For these reasons, it cost a vast number of experiments to prove the existence, and to discover the course, of these vessels. Once found in living animals, they could be injected and dissected in the dead body; but they had been overlooked by Vesalius and the men of his time.
- 65. From the discovery of the lacteals came the discovery of the whole lymphatic system. Daremberg, in his Histoire des Sciences Médicales (Paris, 1870), after an account of Pecquet's work, says:— Up to this point, we have seen English, Italians, and French working together, with more or less success and genius, to trace the true ways of blood and chyle: there is yet one field of work to open up, the lymphatics of the body. The chief honour here belongs, without doubt, to the Swede Rudbeck, though the Dane Bartholin has disputed it with him, with equal acrimony and injustice. Rudbeck's work (1651-54) coincides exactly, in point of time, with the first and second editions, 1651 and 1654, of Pecquet's De Lactibus. It may be said, therefore, that the whole doctrine of the lymphatic system was roughed out half-way through the seventeenth century. III THE GASTRIC JUICE From many causes, the experimental study of the digestive processes came later than the study of the circulation. As an object of speculative thought, digestion was a lower phase of life, the work of crass spirits, less noble than the blood; from the point of view of science, it could not be studied ahead of organic chemistry, and got no help from any other sort of knowledge; and, from the medical point of view, it was the final result of many unknown internal forces that could not be observed or estimated either in life or after death. It did not, like the circulation, centre itself round one problem; it could not be focussed by the work of one man. For these reasons, and especially because of its absolute dependence on chemistry for the interpretation of its facts, it had to bide its time; and Réaumur's experiments are separated from the publication of Harvey's De Motu Cordis et Sanguinis by a hundred and thirty years.
- 66. The following account of the first experiments on digestion is taken from Claude Bernard's Physiologie Opératoire, 1879:— The true experimental study of digestion is of comparatively recent date; the ancients were content to find comparisons, more or less happy, with common facts. Thus, for Hippocrates, digestion was a 'coction': for Galen, a 'fermentation,' as of wine in a vat. In later times, van Helmont started this comparison again: for him, digestion was a fermentation like that of bread: as the baker, having kneaded the bread, keeps a little of the dough to leaven the next lot kneaded, so, said van Helmont, the intestinal canal never completely empties itself, and the residue that it keeps after each digestion becomes the leaven that shall serve for the next digestion. The first experimental studies on the digestion date from the end of the seventeenth century, when the Academy of Florence was the scene of a famous and long controversy between Borelli and Valisnieri. The former saw nothing more in digestion than a purely mechanical act, a work of attrition whereby the ingesta were finely divided and as it were pulverised: and in support of this opinion Borelli invoked the facts that he had observed relating to the gizzard of birds. We know that this sac, with its very thick muscular walls, can exercise on its contents pressure enough to break the hardest bodies. Identifying the human stomach with the bird's gizzard, Borelli was led to attribute to the walls of the stomach an enormous force, estimated at more than a thousand pounds; whose action, he said, was the very essence of digestion. Valisnieri, on the contrary, having had occasion to open the stomach of an ostrich, had found there a fluid which seemed to act on bodies immersed in it; this
- 67. fluid, he said, was the active agent of digestion, a kind of aqua fortis that dissolved food. These two opposed views, resulting rather from observations than from regularly instituted experiments, were the starting-point of the experimental researches undertaken by Réaumur in 1752. To resolve the problem set by Borelli and Valisnieri, Réaumur made birds swallow food enclosed in fenestrated tubes, so that the food, protected from the mechanical action of the walls of the stomach, was yet exposed to the action of the gastric fluid. The first tubes used (glass, tin, etc.) were crushed, bent, or flattened by the action of the walls of the gizzard; and Réaumur failed to oppose to this force a sufficient resistance, till he employed leaden tubes thick enough not to be flattened by a pressure of 484 pounds: which was, in fact, the force exercised by the contractile walls of the gizzard in turkeys, ducks, and fowls under observation. These leaden tubes—filled with ordinary grain, and closed only by a netting that let pass the gastric juices—these tubes, after a long stay in the stomach, still enclosed grain wholly intact, unless it had been crushed before the experiment. When they were filled with meat, it was found changed, but not digested. Réaumur was thus led at first to consider digestion, in the gallinaceæ, as pure and simple trituration. But, repeating these experiments on birds of prey, he observed that digestion in them consists essentially in dissolution, without any especial mechanical action, and that it is the same with the digestion of meat in all animals with membranous stomachs. To procure this dissolving fluid, Réaumur made the birds swallow sponges with threads attached: withdrawing these sponges after a definite period, he squeezed the fluid into a glass, and tested its action on meat. That was the first attempt at artificial digestion in vitro. He did not carry these last
- 68. investigations very far, and did not obtain very decisive results; nevertheless he must be considered as the discoverer of artificial digestion. After Réaumur, the Abbé Spallanzani (1783) made similar observations on many other animals, including carnivora. He showed that even in the gallinaceæ there was dissolution of food, not mere trituration: and observed how after death the gastric fluid may under certain conditions act on the walls of the stomach itself. Henceforth the experimental method had cut the knot of the question raised by the theories of Borelli and Valisnieri: digestion could no longer be accounted anything but a dissolution of food by the fluid of the stomach, the gastric juice. But men had still to understand this gastric juice, and to determine its nature and mode of action. Nothing could be more contradictory than the views on this matter. Chaussier and Dumas, of Montpellier, regarded the gastric juice as of very variable composition, one time alkaline, another acid, according to the food ingested. Side by side with these wholly theoretical opinions, certain results of experiments had led to ideas just as erroneous, for want of rigorous criticism of methods; it was thus that Montègre denied the existence of the gastric juice as a special fluid; what men took for gastric juice, he said, was nothing but the saliva turned acid in the stomach. To prove his point, he made the following experiment:—He masticated a bit of bread, then put it out on a plate; it was at first alkaline, then at the end of some time it became acid. In those days (1813) this experiment was a real embarrassment to the men who believed in the existence of a special gastric juice: we have now no need to refute it. These few instances suffice to show how the physiologists were unsettled as to the nature and properties of the gastric juice. Then (1823) the Academy
- 69. had the happy idea of proposing digestion as a subject for a prize. Tiedemann and Gmelin in Germany, Leuret and Lassaigne in France, submitted works of equal merit, and the Academy divided the prize between them. The work of Tiedemann and Gmelin is of especial interest to us on account of the great number of their experiments, from which came not only the absolute proof of the existence of the gastric juice, but also the study of the transformation of starch into glucose. Thus the theory of digestion entered a new phase: it was finally recognised, at least for certain substances, that digestion is not simply dissolution, but a true chemical transformation. (Cl. Bernard, loc. cit.) In 1825 Dr. William Beaumont, a surgeon in the United States Army, began his famous experiments on Alexis St. Martin, a young Canadian travelling for the American Fur Company, who was shot in the abdomen on 6th June 1822, and recovered, but was left with a permanent opening in his stomach. Since the surgery of those days did not favour an operation to close this fistula, Dr. Beaumont took St. Martin into his service, and between 1825 and 1833 made a vast number of experiments on him. These he published,[2] and they were of great value. But it is to be noted that the ground had been cleared already, fifty years before, by Réaumur and Spallanzani:— I make no claim to originality in my opinions, as it respects the existence and operation of the gastric juice. My experiments confirm the doctrines (with some modifications) taught by Spallanzani, and many of the most enlightened physiological writers. (Preface to Dr. Beaumont's book.) Further, it is to be noted that Alexis St. Martin's case proves that a gastric fistula is not painful. Scores of experiments were made on him, off and on, for nine years:—
- 70. During the whole of these periods, from the spring of 1824 to the present time (1833), he has enjoyed general good health, and perhaps suffered much less predisposition to disease than is common to men of his age and circumstances in life. He has been active, athletic, and vigorous; exercising, eating, and drinking like other healthy and active people. For the last four months he has been unusually plethoric and robust, though constantly subjected to a continuous series of experiments on the interior of the stomach; allowing to be introduced or taken out at the aperture different kinds of food, drinks, elastic catheters, thermometer tubes, gastric juice, chyme, etc., almost daily, and sometimes hourly. Such have been this man's condition and circumstances for several years past; and he now enjoys the most perfect health and constitutional soundness, with every function of the system in full force and vigour. (Dr. Beaumont, loc. cit. p. 20.) In 1834 Eberlé published a series of observations on the extraction of gastric juice from the mucous membrane of the stomach after death; in 1842 Blondlot of Nancy studied the gastric juice of animals by the method of a fistula, such as Alexis St. Martin had offered for Dr. Beaumont's observation. After Blondlot, came experiments on the movements of the stomach, and on the manifold influences of the nervous system on digestion. It has been said, times past number, that an animal with a fistula is in pain. It is not true. The case of St. Martin is but one out of a multitude of these cases: an artificial orifice of this kind is not painful. IV GLYCOGEN
- 71. Claude Bernard's discovery of glycogen in the liver had a profound influence both on physiology and on pathology. Take first its influence on pathology. Diabetes was known to Celsus, Aretæus, and Galen; Willis, in 1674, and Morton, in 1675, noted the distinctive sweetness of the urine; and their successors proved the presence of sugar in it. Rollo, in 1787, observed that vegetable food was bad for diabetic patients, and introduced the strict use of a meat diet. But Galen had believed that diabetes was a disease of the kidneys, and most men still followed him: nor did Rollo greatly advance pathology by following not Galen, but Aretæus. Later, with the development of organic chemistry, came the work of Chevreuil (1815), Tiedemann and Gmelin (1823), and other illustrious chemists: and the pathology of diabetes grew more and more difficult:— These observations gave rise to two theories: the one, that sugar is formed with abnormal rapidity in the intestine, absorbed into the blood, and excreted in the urine; the other, that diabetes is due to imperfect destruction of the sugar, either in the intestine or in the blood. Some held that it underwent conversion into lactic acid as it was passing through the intestinal walls, while others believed it to be destroyed in the blood by means of the alkali therein contained.[3] Thus, before Claude Bernard (1813-1878), the pathology of diabetes was almost worthless. And, in physiology, his work was hardly less important than the work of Harvey. A full account of it, in all its bearings, is given in Sir Michael Foster's Life of Claude Bernard (Fisher Unwin, 1899). In Bernard's Leçons sur le Diabète et la Glycogenèse Animale (Paris, 1877), there is a sentence that has been misquoted many times:— Sans doute, nos mains sont vides aujourd'hui, mais notre bouche peut être pleine de légitimes promesses pour l'avenir.
- 72. This sentence has been worked so hard that some of the words have got rubbed off it: and the statement generally made is of this kind:— Claude Bernard himself confessed that his hands were empty, but his mouth was full of promises. Of course, he did not mean that he was wrong in his facts. But, in this particular lecture, he is speaking of the want of more science in practice, looking forward to a time when treatment should be based on science, not on tradition. Medicine, he says, is neither science nor art. Not science—Trouverait-on aujourd'hui un seul médecin raisonnable et instruit osant dire qu'il prévoit d'une manière certaine la marche et l'issue d'une maladie ou l'effet d'une remède? Not art, because art has always something to show for its trouble: a statue, a picture, a poem—Le médecin artiste ne crée rien, et ne laisse aucune œuvre d'art, à moins d'appliquer ce titre à la guérison du malade. Mais quand le malade meurt, est-ce également son œuvre? Et quand il guérit, peut-il distinguer sa part de celle de la nature? To Claude Bernard, experiments on animals for the direct advancement of medicine seemed a new thing: new, at all events, in comparison with the methods of some men of his time. He was only saying what Sir John Burdon Sanderson said in 1875 to the Royal Commission:— It is my profound conviction that a future will come, it may be a somewhat distant future, in which the treatment of disease will be really guided by science. Just as completely as mechanical science has come to be the guide of the mechanical arts, do I believe, and I feel confident, that physiological science will eventually come to be the guide of medicine and surgery. Anyhow, lecturing a quarter of a century ago on diabetes, his special subject, Claude Bernard spoke out his longing to compel men into the ways of science, to give them some immediate sign which they could not refuse to see:—
- 73. At this present time, medicine is passing from one period to another. The old traditions are losing ground, and scientific medicine (la médecine expérimentale) has got hold of all our younger men: every day it gains ground, and will establish itself against all its critics, and in spite of the excesses of those who are over-zealous for its honour.... And when men ask us what are the results of scientific medicine, we are driven to answer that it is scarcely born, that it is still in the making. Those who care for nothing but an immediate practical application must remember Franklin's words, What is the use of a new-born child, but to become a man? If you deliberately reject scientific medicine, you fail to see the natural development of man's mind in all the sciences. Without doubt, our hands are empty to-day, but our mouth may well be filled with legitimate promises for the future. He died in 1878. The following account of the discovery of glycogen is taken from his Nouvelle Fonction du Foie (Paris, 1853):— My first researches into the assimilation and destruction of sugar in the living organism were made in 1843: and in my inaugural thesis (Dec. 1843) I published my first experiments on the subject. I succeeded in demonstrating a fact hitherto unknown, that cane-sugar cannot be directly destroyed in the blood. If you inject even a very small quantity of cane-sugar, dissolved in water, into the blood or under the skin of a rabbit, you find it again in the urine unchanged, with all its chemical properties the same.... I had soon to give up my first point of view, because this question of the existence of a sugar-producing organ, that I had thought such a hard problem of physiology, was really the first thing revealed to me, as it were of itself, at once. He kept two dogs on different diets, one with sugar, the other without it; then killed them during digestion, and tested the blood in
- 74. the hepatic veins:— What was my surprise, when I found a considerable quantity of sugar in the hepatic veins of the dog that had been fed on meat only, and had been kept for eight days without sugar: just as I found it in the other dog that had been fed for the same time on food rich in sugar.... Finally, after many attempts—après beaucoup d'essais et plusieurs illusions que je fus obligé de rectifier par des tâtonnements—I succeeded in showing, that in dogs fed on meat the blood passing through the portal vein does not contain sugar before it reaches the liver; but when it leaves the liver, and comes by the hepatic veins into the inferior vena cava, this same blood contains a considerable quantity of a sugary substance (glucose). His further discovery, that this formation of sugar is increased by puncture of the floor of the fourth ventricle, was published in 1849. It is impossible to exaggerate the importance of Claude Bernard's single-handed work in this field of physiology and pathology:— As a mere contribution to the history of sugar within the animal body, as a link in the chain of special problems connected with digestion and nutrition, its value was very great. Even greater, perhaps, was its effect as a contribution to general views. The view that the animal body, in contrast to the plant, could not construct, could only destroy, was, as we have seen, already being shaken. But evidence, however strong, offered in the form of numerical comparisons between income and output, failed to produce anything like the conviction which was brought home to every one by the demonstration that a substance was actually formed within the animal body, and by the exhibition of the substance so formed.
- 75. No less revolutionary was the demonstration that the liver had other things to do in the animal economy besides secreting bile. This, at one blow, destroyed the then dominant conception that the animal body was to be regarded as a bundle of organs, each with its appropriate function, a conception which did much to narrow inquiry, since when a suitable function had once been assigned to an organ there seemed no need for further investigations.... No less pregnant of future discoveries was the idea suggested by this newly-found-out action of the hepatic tissue, the idea happily formulated by Bernard as 'internal secretion.' No part of physiology is at the present day being more fruitfully studied than that which deals with the changes which the blood undergoes as it sweeps through the several tissues, changes by the careful adaptation of which what we call the health of the body is secured, changes the failure or discordance of which entails disease. The study of these internal secretions constitutes a path of inquiry which has already been trod with conspicuous success, and which promises to lead to untold discoveries of the greatest moment; the gate to this path was opened by Bernard's work. (Sir M. Foster, loc. cit.) But the work to be done, before all the clinical facts of the disease can be stated in terms of physiology, is not yet finished. In England, especial honour is due to Dr. Pavy for his life-long study of this most complex problem. V THE PANCREAS Here again Claude Bernard's name must be put first. Before him, the diverse actions of the pancreatic juice had hardly been studied.
- 76. Vesalius, greatest of all anatomists, makes no mention of the duct of the pancreas, and speaks of the gland itself as though its purpose were just to support the parts in its neighbourhood—ut ventriculo instar substerniculi ac pulvinaris subjiciatur. The duct was discovered by Wirsung, in 1642: but anatomy could not see the things that belong to physiology. Lindanus (1653) said, I cannot doubt that the pancreas expurgates, in the ordinary course of Nature, those impurities of the blood that are too crass and inept to be tamed by the spleen: and, in the extraordinary course, all black bile, begotten of disease or intemperate living. Wharton (1656) said, It ministers to the nerves, taking up certain of their superfluities, and remitting them through its duct into the intestines. And Tommaso Bartholini (1666) called it the biliary vesicle of the spleen. This chaos of ideas was brought into some sort of order by Regnier de Graaf, pupil of François de Bois (Sylvius). De Bois had guessed that the pancreas must be considered not according to its position in the body, but according to its structure: that it was analogous to the salivary glands. He urged his pupil to make experiments on it: and de Graaf says:— I put my hand to the work: and though many times I despaired of success, yet at last, by the blessing of God on my work and prayers, in the year 1660 I discovered a way of collecting the pancreatic juice. And, by further experiment, he refuted Bartholini's theory that the pancreas was dependent on the spleen. Sylvius had supposed that the pancreatic juice was slightly acid, and de Graaf failed to note this mistake; but it was corrected by Bohn's experiments in 1710. Nearly two hundred years come between Regnier de Graaf and Claude Bernard: it is no wonder that Sir Michael Foster says that de Graaf's work was very imperfect and fruitless. So late as 1840, there was yet no clear understanding of the action of the pancreas.
- 77. Physiology could not advance without organic chemistry; de Graaf could no more discover the amylolytic action of the pancreatic juice than Galvani could invent wireless telegraphy. The physiologists had to wait till chemistry was ready to help them:— Of course, while physical and chemical laws were still lost in a chaos of undetermined facts, it was impossible that men should analyse the phenomena of life: first, because these phenomena go back to the laws of chemistry and physics; and next, because they cannot be studied without the apparatus, instruments, and all other methods of analysis that we owe to the laboratories of the chemists and the physicists. (Cl. Bernard, Phys. Opér., p. 61.) Therefore de Graaf failed, because he got no help from other sciences. But it cannot be called failure; he must be contrasted with the men of his time, Lindanus and Bartholini, facts against theories, not with men of this century. And Claude Bernard went back to de Graaf's method of the fistula, having to guide him the facts of chemistry observed by Valentin, Tiedemann and Gmelin, and Eberlé. His work began in 1846, and the Académie des Sciences awarded a prize to it in 1850:— Let this vague conception (the account of the pancreas given in Johannes Müller's Text-book of Physiology) be compared with the knowledge which we at present have of the several distinct actions of the pancreatic juice, and of the predominant importance of this fluid not only in intestinal digestion but in digestion as a whole, and it will be at once seen what a great advance has taken place in this matter since the early forties. That advance we owe in the main to Bernard. Valentin, it is true, had in 1844 not only inferred that the pancreatic juice had an action on starch, but confirmed his view by actual experiment with the juice expressed from the gland; and Eberlé had suggested that the juice had some action on fat; but
- 78. Bernard at one stroke made clear its threefold action. He showed that it on the one hand emulsified, and on the other hand split up, into fatty acids and glycerine, the neutral fats; he clearly proved that it had a powerful action on starch, converting it into sugar; and lastly, he laid bare its remarkable action on proteid matters. (Sir Michael Foster, loc. cit.) Finally came the discovery that the pancreas—apart from its influences on digestion—contributes its share, like the ductless glands, to the general chemistry of the body:— It was discovered, a few years ago, by von Mering and Minkowski, that if, instead of merely diverting its secretion, the pancreas is bodily removed, the metabolic processes of the organism, and especially the metabolism of carbo-hydrates, are entirely deranged, the result being the production of permanent diabetes. But if even a very small part of the gland is left within the body, the carbo- hydrate metabolism remains unaltered, and there is no diabetes. The small portion of the organ which has been allowed to remain (and which need not even be left in its proper place, but may be transplanted under the skin or elsewhere) is sufficient, by the exchanges which go on between it and the blood generally, to prevent those serious consequences to the composition of the blood, and the general constitution of the body, which result from the complete removal of this organ. (Prof. Schäfer, 1894.) Here, in this present study of pancreatic diabetes, by Dr. Vaughan Harley and others, are facts as important as any that Bernard made out: in no way contradicting his work, but adding to it. The pancreas is no longer taken to be only a sort of salivary gland out of place: over and above the secretion that it pours into the intestines, it has an internal secretion, a constituent of the blood: it belongs not only to the digestive system, but also, like the thyroid gland and the
- 79. suprarenal capsules, to the whole chemistry of the blood and the tissues. So far has physiology come, unaided by anatomy, from the fantastic notions of Lindanus and the men of his time: and has come every inch of the way by the help of experiments on animals. Professor Starling's observations, on the chemical influence of the duodenal mucous membrane on the flow of pancreatic fluid, have advanced the subject still further. VI THE GROWTH OF BONE The work of du Hamel proved that the periosteum is one chief agent in the growth of bone. Before him, this great fact of physiology was unknown; for the experiments made by Anthony de Heide (1684), who studied the production of callus in the bones of frogs, were wholly useless, and serve only to show that men in his time had no clear understanding of the natural growth of bone. De Heide says of his experiments:— From these experiments it appears—forsan probatur— that callus is generated by extravasated blood, whose fluid particles being slowly exhaled, the residue takes the form of the bone: which process may be further advanced by deciduous halitus from the ends of the broken bone. And Clopton Havers, in his Osteologia Nova (London, 1691), goes so far the wrong way that he attributes to the periosteum not the production of bone, but the prevention of over-production; the periosteum, he says, is put round the shaft of a bone to compress it, lest it grow too large. Du Hamel's discovery (1739-1743) came out of a chance observation, made by John Belchier,[4] that the bones of animals fed near dye-works were stained with the dye. Belchier therefore put a bird on food mixed with madder, and found that its bones had taken
- 80. up the stain. Then du Hamel studied the whole subject by a series of experiments. To estimate the advance that he gave to physiology, contrast de Heide's fanciful language with the title of one of du Hamel's papers—Quatrième Mémoire sur les Os, dans lequel on se propose de rapporter de nouvelles preuves qui établissent que les os croissent en grosseur par l'addition de couches osseuses qui tirent leur origine du périoste, comme le corps ligneux des Arbres augmente en grosseur par l'addition de couches ligneuses qui se forment dans l'écorce. Or take an example of du Hamel's method:— Three pigs were destined to clear up my doubts. The first, six weeks old, was fed for a month on ordinary food, with an ounce daily of madder-juice—garance grappe— put in it. At the end of the month, we stopped the juice, and fed the pig in the ordinary way for six weeks, and then killed it. The marrow of the bones was surrounded by a fairly thick layer of white bone: this was the formation of bone during the first six weeks of life, without madder. This ring of white bone was surrounded by another zone of red bone: this was the formation of bone during the administration of the madder. Finally, this red zone was covered with a fairly thick layer of white bone: this was the layer formed after the madder had been left off.... We shall have no further difficulty in understanding whence transudes the osseous juice that was thought necessary for the formation of callus and the filling-up of the wounds of the bones, now we see that it is the periosteum that fills up the wounds, or is made thick round the fractures, and afterward becomes of the consistence of cartilage, and at last acquires the hardness of bones. These results, confirmed by Bazan (1746) and Boehmer (1751), were far beyond anything that had yet been known about the periosteum. But the growth of bone is a very complex process: the naked eye sees only the grosser changes that come with it; and du
- 81. Hamel's ingenious comparison between the periosteum and the bark of trees was too simple to be exact. Therefore his work was opposed by Haller, and by Dethleef, Haller's pupil: and the great authority of Haller's name, and the difficulties lying beyond du Hamel's plain facts, brought about a long period of uncertainty. Bordenave (1756) found reasons for supporting Haller; and Fougeroux (1760) supported du Hamel. Thus men came to study the whole subject with more accuracy—the growth in length, as well as the growth in thickness; the medullary cavity, the development of bone, the nutrition and absorption of bone. Among those who took up the work were Bichat, Hunter, Troja, and Cruveilhier; and they recognised the surgical aspect of these researches in physiology. After them, the periosteal growth of bone became, as it were, a part of the principles of surgery. From this point of view of practice, issued the experiments made by Syme (1837) and Stanley (1849): which proved the importance of the epiphysial cartilages for the growth of the bones in length, and the risk of interfering with these cartilages in operations on the joints of children. Finally, with the rise of anæsthetics and of the antiseptic method, came the work of Ollier, of Lyon, whose good influence on the treatment of these cases can hardly be over-estimated. VII THE NERVOUS SYSTEM As with the circulatory system, so with the nervous system, the work of Galen was centuries ahead of its time. Before him, Aristotle, who twice refers to experiments on animals, had observed the brain during life: for he says, In no animal has the blood any feeling when it is touched, any more than the excretions; nor has the brain, or the marrow, any feeling, when it is touched: but there is reason for believing that he neither recognised the purpose of the brain, nor understood the distribution of the nerves. Galen, by the help of the experimental method, founded the physiology of the nervous system:—
- 82. Galen's method of procedure was totally different to that of an anatomist alone. He first reviewed the anatomical position, and by dissection showed the continuity of the nervous system, both central and peripheral, and also that some bundles of nerve fibres were distributed to the skin, others to the muscles. Later, by process of the physiological experiment of dividing such bundles of fibres, he showed that the former were sensory fibres and the latter motor fibres. He further traced the nerves to their origins in the spinal cord, and their terminations as aforesaid. From these observations and experiments he was able to deduce the all-important fact that different nerve-roots supplied different groups of muscles and different areas of the skin.... An excellent illustration of his method, and of the fact that we ought not to treat symptoms, but the causes of symptoms, is shown very clearly in one of the cases which Galen records as having come under his care. He tells us that he was consulted by a certain sophist called Pausanias, who had a severe degree of anæsthesia of the little and ring fingers. For this loss of sensation, etc., the medical men who attended him applied ointments of various kinds to the affected fingers; but Galen, considering that that was a wrong principle, inquired into the history, and found that while the patient was driving in his chariot he had accidentally fallen out and struck his spine at the junction of the cervical and dorsal regions. Galen recognised that he had to do with a traumatism affecting the eighth cervical and first dorsal nerve; therefore, he says, he ordered that the ointments should be taken off the hand and placed over the spinal column, so as to treat the really affected part, and not apply remedies to merely the referred seat of pain.[5] Galen, by this sort of work, laid the foundations of physiology; but the men who came after him let his facts be overwhelmed by
- 83. fantastic doctrines: all through the ages, from Galen to the Renaissance, no great advance was made toward the interpretation of the nervous system. Long after the Renaissance, his authority still held good; his ghost was not laid even by Paracelsus and Vesalius, it haunted the medical profession so late as the middle of the seventeenth century; but the men who worshipped his name missed the whole meaning of his work. This long neglect of the experimental method left such a gap in the history of physiology, that Sir Charles Bell seems to take up the experimental study of the nervous system at the point where Galen had stopped short; we go from the time of Commodus to the time of George the Third, and there is Bell, as it were, putting the finishing touch to Galen's facts. It is true that experiments had been made on the nervous system by many men; but a dead weight of theories kept down the whole subject. For a good instance, how imagination hindered science, there is the following list, made by Dr. Risien Russell, of theories about the cerebellum:— Galen was of opinion that the cerebellum must be the originator of a large amount of vital force. After him, and up to the time of Willis, the prevalent idea seems to have been that it was the seat of memory; while Bourillon considered it the seat of instinct and intelligence. Willis supposed that it presided over involuntary movements and organic functions; and this view, though refuted by Haller, continued in the ascendency for some time. Some believed strongly in its influence on the functions of organic life; and according to some, diseases of the cerebellum appeared to tell on the movements of the heart.... Haller believed it to be the seat of sensations, as well as the source of voluntary power; and there were many supporters of the theory that the cerebellum was the seat of the sensory centres. Renzi considered this organ the nervous centre by which we perceive the reality of the external world, and direct and fix our senses on the things round us. Gall, and later Broussais, and others,
- 84. held that this organ presided over the instinct of reproduction, or the propensity to love; while Carus regarded it as the seat of the will also. Rolando looked on it as the source of origin of all movements. Jessen adduced arguments in favour of its being the central organ of feeling, or of the soul, and the principal seat of the sensations. It is plain, from this list, that physiology had become obscured by fanciful notions of no practical value. If a better understanding of the nervous system could have been got without experiments on animals, why had men to wait so long for it? The Italian anatomists had long ago given them all the anatomy that was needed to make a beginning; the hospitals, and practice, had given them many hundred years of clinical facts; nervous diseases and head injuries were common enough in the Middle Ages; and by the time of Ambroise Paré, if not before, post-mortem examinations were allowed. The one thing wanted was the experimental method; and, for want of it, the science of the nervous system stood still. Experiments had been made; but the steady, general, unbiassed use of this method had been lost sight of, and men were more occupied with logic and with philosophy. Then, in 1811, came Sir Charles Bell's work. If any one would see how great was the need of experiments on animals for the interpretation of the nervous system, let him contrast the physiology of the eighteenth century with that one experiment by Bell which enabled him to say, I now saw the meaning of the double connection of the nerves with the spinal marrow. It is true that this method is but a part of the science of medicine; that experiment and experience ought to go together like the convexity and the concavity of a curve. But it is true also that men owe their deliverance from ignorance about the nervous system more to experiments on animals than to any other method of observing facts. 1. Sir Charles Bell (1778-1842)
- 85. The great authority of Sir Charles Bell has been quoted a thousand times against all experiments on animals:— Experiments have never been the means of discovery; and a survey of what has been attempted of late years in physiology, will prove that the opening of living animals has done more to perpetuate error than to confirm the just views taken from the study of anatomy and natural motions. He wrote, of course, in the days before bacteriology, before anæsthetics; he had in his mind neither inoculations, nor any observations made under chloroform or ether, but just the opening of living animals. He had also in his mind, and always in it, a great dislike against the school of Magendie. Let all that pass; our only concern here is to know whether these words are true of his own work. They occur in a paper, On the Motions of the Eye, in Illustration of the Uses of the Muscles and Nerves of the Orbit; communicated by Sir Humphry Davy to the Royal Society, and read March 20, 1823.[6] This essay was one of a series of papers on the nervous system, presented to the Royal Society during the years 1821-1829. In 1830, having already published four of these papers under the title, The Exposition of the Nervous System, Bell published all six of them, under the title, The Nervous System of the Human Body. In his Preface to this book (1830) he quotes the earliest of all his printed writings on the nervous system, a pamphlet, printed in 1811, under the title, An Idea of a New Anatomy of the Brain, Submitted for the Observation of the Authors Friends. We have therefore two statements of his work, one in 1811, the other in 1823 and 1830. The first of them was written when his work was still new before his eyes. Those who say that experiments did not help Bell in his great discovery—the difference between the anterior and the posterior
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