![Global warming
• Each of the last three decades has been successively warmer at the Earth’s surface
than any preceding decade since 1850.
• The period from 1983 to 2012 was likely the warmest 30-year period of the last
1400 years in the Northern Hemisphere, where such assessment is possible
• The globally averaged combined land and ocean surface temperature data as
calculated by a linear trend, show a warming of 0.85 [0.65 to 1.06] °C over the
period 1880 to 2012. the average global temperature for 2016 was 0.9 °C above
pre-industrial levels.
• Sea surface temperatures in the Caribbean are projected to warm, perhaps by up
to 2oC or higher by the end of the century.
9](https://image.slidesharecdn.com/ccsciencepptjournalistssscott-170628205151/85/Climate-Change-and-Its-Impacts-Emerging-Science-9-320.jpg)
![Sea level rise
• Over the period 1901 to 2010, global mean sea level rose by 0.19 [0.17 to 0.21] m
(i.e. over 7 inches)
• The rate of sea-level rise since the mid-19th century has been larger than the
mean rate during the previous two millennia
• Caribbean sea levels are projected to rise by up to 0.24 m (i.e. Over 9 inches) by
mid century. Sea level rise is not the same everywhere – for example, sea level in
Guyana is projected to be twice that of the regional level.
10](https://image.slidesharecdn.com/ccsciencepptjournalistssscott-170628205151/85/Climate-Change-and-Its-Impacts-Emerging-Science-10-320.jpg)
Climate Change and Its Impacts: Emerging Science
- 1. 1
- 2. Climate is the average weather usually taken over a 30-year time period for a particular region and time period. Climate is long term. Weather is what is happening in the atmosphere on any given day, in a specific place. Weather is short term. Climate system: • Atmosphere: The atmosphere covers the Earth. It is a thin layer of mixed gases which make up the air we breathe. This thin layer also helps the Earth from becoming too hot or too cold. • Oceans: Oceans cover about 70 percent of Earth's surface. Their large size and thermal properties allow them to store a lot of heat. • Land: Land covers 27 percent of Earth's surface and land topography influences weather patterns. • Ice: Ice is the world's largest supply of freshwater. It covers the remaining 3 percent of Earth's surface including most of Antarctica and Greenland. Ice plays an important role in regulating climate, because it is highly reflective. • Biosphere: The biosphere is the part of Earth's atmosphere, land, and oceans that supports any living plant, animal, or organism. It is the place where plants and animals, including humans, live. 2
- 3. The atmosphere, or the layer of air that surrounds the earth protects life on earth by absorbing the suns energy and keeping the earth warm. This is called the Greenhouse effect. Certain gases in the atmosphere are special in a way, in that they can trap the suns heat. These gases include carbon dioxide and water vapor, among others. These gases are generally called heat trapping gases or greenhouse gases. 3
- 4. The Industrial Revolution, which was the transition to new manufacturing processes in 1760 to sometime about 1840, brought about some unexpected changes to the atmosphere. The Industrial revolution moved us away from hand production methods to machines, new chemical manufacturing, iron production processes, improved efficiency of water power, the increasing use of steam power, and the development of machine tools. But more concerning is that it also included the change from wood and other bio-fuels to coal and later other fossil fuels. Burning of these fuels releases carbon dioxide and other heat trapping gasses into the atmosphere. And so the rate at which these gases are being release since the Industrial Revolution is higher than ever before. 4
- 5. •The pre industrial level of carbon dioxide was about 280ppm; The 2016 approx. 409 ppm •About 40% of these emissions to date have remained in the atmosphere •The rest was removed from the atmosphere and stored on land (in plants and soils) and in the ocean. •The ocean has absorbed about 30% of the emitted anthropogenic CO2, causing ocean acidification. •About half of the anthropogenic CO2 emissions between 1750 and 2011 have occurred in the last 40 years Now not only are we emitting more heat trapping gases (i.e. greenhouse gases), such as carbon dioxide into the atmosphere, but we are also destroying forests (deforestation) and polluting oceans, two systems that help remove carbon dioxide from the atmosphere. So in effect, we have increased our carbon footprint, that is the amount of carbon dioxide and other carbon compounds released due to the use of fossil fuels. It therefore becomes obvious that the overall amount of carbon dioxide now reaching the atmosphere will continue to increase as these activities continue. 5
- 6. Ocean Acidification - Once dissolved in seawater, CO2 reacts with water, H2O,to form carbonic acid, H2CO3:CO2 + H2O ↔ H2CO3. Carbonic acid dissolves rapidly to form H+ ions (an acid) and bicarbonate, HCO3-(a base). Seawater is naturally saturated with another base, carbonate ion (CO3 −2) that acts like an antacid to neutralize the H+, forming more bicarbonate. The net reaction looks like this: CO2 + H2O + CO3 −2 → 2HCO3- As carbonate ion gets depleted, seawater becomes under-saturated with respect to two calcium carbonate minerals vital for shell-building, aragonite and calcite. 6
- 7. Total annual anthropogenic greenhouse gas (GHG) emissions (gigatonne of CO2- equivalent per year, GtCO2-eq/yr) for the period 1970 to 2010 by gases • Forestry and Other Land Use (FOLU) • fluorinated gases covered under the Kyoto Protocol (F-gases). • Pound for pound, the comparative impact of CH4 on climate change is over 20 times greater than CO2 over a 100-year period. However, Methane's lifetime in the atmosphere is much shorter than carbon dioxide • Carbon dioxide equivalency is a quantity that describes, for a given mixture and amount of greenhouse gas, the amount of CO2 that would have the same global warming potential (GWP), when measured over a specified timescale (generally, 100 years). Today's CO2 concentration is the highest in 15 million years. 7
- 8. 8
- 9. Global warming • Each of the last three decades has been successively warmer at the Earth’s surface than any preceding decade since 1850. • The period from 1983 to 2012 was likely the warmest 30-year period of the last 1400 years in the Northern Hemisphere, where such assessment is possible • The globally averaged combined land and ocean surface temperature data as calculated by a linear trend, show a warming of 0.85 [0.65 to 1.06] °C over the period 1880 to 2012. the average global temperature for 2016 was 0.9 °C above pre-industrial levels. • Sea surface temperatures in the Caribbean are projected to warm, perhaps by up to 2oC or higher by the end of the century. 9
- 10. Sea level rise • Over the period 1901 to 2010, global mean sea level rose by 0.19 [0.17 to 0.21] m (i.e. over 7 inches) • The rate of sea-level rise since the mid-19th century has been larger than the mean rate during the previous two millennia • Caribbean sea levels are projected to rise by up to 0.24 m (i.e. Over 9 inches) by mid century. Sea level rise is not the same everywhere – for example, sea level in Guyana is projected to be twice that of the regional level. 10
- 11. Ocean Acidification • Since the beginning of the industrial era, oceanic uptake of CO2 has resulted in acidification of the ocean; • the pH of ocean surface water has decreased by 0.1, corresponding to a 26% increase in acidity, measured as hydrogen ion concentration 11
- 12. More intense storms – compounded by sea level rise GCMs (global) show a median decrease of up to 22% for annual rainfall. While the RCM (regional) suggests a decrease of up to 57%. The warming trend is expected to continue. The country is projected to be warmer by up to 1.2 oC by the 2030s, 2.1 oC by the 2060s, and 3.6 oC by the end of the century. 12
- 13. Tourism is Saint Lucia's main source of jobs and income - accounting for 65% of GDP - and the island's main source of foreign exchange earnings. 13
- 14. Food security is important as an independent country, else the country becomes highly dependent on the outside world. Everything has to be imported. Being food secure is the situation where there is reliable access to a sufficient amount of affordable, nutritious food. 14
- 15. • A small positive anomaly of 1-2 degrees C for 5-10 weeks during the summer season will usually induce bleaching. • 2005 bleaching event resulted after prolonged warming period (about 1 degree C). Corals' reproductive organs are also damaged by warmer water whether they bleach or not - they produce many fewer eggs and testes in warmer water (e.g., when water temperatures are > 30 C). • Surveys conducted in Saint Lucia show that fifty to eighty percent of corals along the west coast have been bleached. There was also adecline in white sea urchins – no recruitment; and decline in dolphin fish (mahi mahi; dowad) catch. • Percent of visitors in Saint Lucia classified as visiting at least in part due to the coral reef: 25% (World Resources Institute, 2005) • Coral Reef-associated Tourism and Recreation (US$160 – 194 M), Coral Reef- associated Fisheries (US$.5 –.8 M), Shoreline Protection by Coral Reefs - avoided damages – 2007 (US $28 – 50 M): Total: US$188.5 – US$244.8M per annum (World Resources Institute, 2005) • Changing sea conditions could also be responsible for the increase in Sargassum (seaweed) currently affecting fishing boats and possible impacting fisheries such as the flying fish. 15
- 16. 16
- 17. Small islands were fighting to ensure that the increase in temperature does not surpass 1.5 degrees C above pre-industrial levels. However, many others were content with agreeing to a goal of 2.0 degrees C. The science shows that even with a warming of 1,5, small islands and other unique and threatened systems stand to be negatively impacted. Note that these predictions do not take into account the current stresses on the environment such as environmental pollution; and as such, the levels of impact depicted in this figure are likely higher than predicted. According to a UNEP (2000) report, about 15,000 tons of nitrogen enters the Caribbean sea from untreated sewage and non-point runoff from agriculture. This same report, indicates that about 300, 000 tons of solid waste end up in waterways and ultimately into the Caribbean Sea. 17
- 18. Note: Caribbean Region is in low latitude 18
- 19. 19