Chapt01 Lecture

Learning Outcomes After studying this chapter, you should be able to answer the following questions: • Describe several of the most important environmental problems facing the world. Are there signs of hope for solving these problems? • What do we mean by sustainability and sustainable development? • Why does science support—but rarely prove—particular theories? • How can scientists know if their research is reliable and important? • How can critical thinking help us understand environmental issues? • Explain how we can use graphs and statistics to answer questions in environmental science. • What are some arguments for conservation or preservation of nature? 1-

Today we are faced with a challenge that calls for a shift in our thinking, so that humanity stops threatening its life-support system. –Wangari Maathai, winner of 2004 Nobel Peace Prize 1-

1.1 Understanding Our Environment The conditions on Earth are unique. Perfect for the existence of life as we know it. The life sustaining ecosystems on which we all depend are unique in the universe, as far as we know. 1-

What is environmental science? Environmental science is the systematic study of our environment and our place in it. Because environmental problems are complex, environmental science draws on many fields of knowledge (fig 1.4). 1-

1.2 Environmental Problems and Opportunities Polluted water contributes to the death of more than 15 million people every year, most of them children under age 5. Food supplies: currently more than 850 million people are chronically undernourished. Energy resources: Fossil fuel supplies are diminishing. There are many problems associated with them. 1-

Environmental Problems Climate change : Burning fossil fuels, making cement, cultivating rice paddies, clearing forests, and other human activities release carbon dioxide and other so-called greenhouse gases, which trap heat in the atmosphere. 1-

Environmental Problems Air quality: Air quality has worsened dramatically in many areas Biodiversity loss: Biologists report that habitat destruction, overexploitation, pollution, and introduction of exotic organisms are eliminating species at a rate comparable to the great extinction that marked the end of the age of dinosaurs. 1.8

Environmental Problems continued…. Marine resources: The ocean is an irreplaceable food resource for many people. 1-

Environmental Opportunities Marine resources : Around the world, people who depend on seafood for their livelihood and sustenance are finding that setting aside marine reserves can restore fish populations as well as promote human development. 1-

Environmental Opportunities Population has stabilized in most industrialized countries and even in some very poor countries where social security and democracy have been established. Over the past 25 years, the average number of children born per woman worldwide has decreased from 6.1 to 2.6 1.11

Environmental Opportunities continued… Health: The incidence of life-threatening infectious diseases has been reduced sharply in most countries during the past century, Life expectancies have nearly doubled, on average. Conservation of forests and nature preserves: Deforestation has slowed in Asia, from more than 8 percent during the 1980s to less than 1 percent in the 1990s. 1-

Environmental Opportunities Renewable energy: Encouraging progress is being made in a transition to renewable energy sources. The European Union has announced a goal of obtaining 22 percent of its electricity and 12 percent of all energy from renewable sources by 2010. Information: The increased speed at which information and technology now flow around the world holds promise that we can continue to find solutions to our environmental dilemmas. 1.13

1.3 Human Dimensions of Environmental Science 1-

Sustainability is a central theme Sustainability is a search for ecological stability and human progress that can last over the long term. Sustainable development is “meeting the needs of the present without compromising the ability of future generations to meet their own needs.” 1-

Indigenous peoples are guardians of much of the world’s biodiversity Often, the 500 million indigenous people who remain in traditional homelands still possess valuable ecological wisdom and remain the guardians of little- disturbed habitats 1-

1.4 Science Helps Us Understand Our Environment 1-

Deductive and inductive reasoning are both useful Logical reasoning from general to specific is known as deductive reasoning. Reasoning from many observations to produce a general rule is inductive reasoning. 1-

The scientific method is an orderly way to examine problems 1. Observe that your flashlight doesn’t light; also, there are three main components of the lighting system (batteries, bulb, and switch). 2. Propose a hypothesis, a testable explanation: “The fl ashlight doesn’t work because the batteries are dead.” 3. Develop a test of the hypothesis and predict the result that would indicate your hypothesis was correct: “I will replace the batteries; the light should then turn on.” 4. Gather data from your test: After you replaced the batteries, did the light turn on? 5. Interpret your results: If the light works now, then your hypothesis was right; if not, then you should formulate a new hypothesis, perhaps that the bulb is faulty, and develop a new test for that hypothesis. 1-

Understanding probability helps reduce uncertainty Probability is a measure of how likely something is to occur. 1-

Experimental Design A natural experiment, is one that involves observation of events that have already happened. Manipulative experiments have conditions deliberately altered, and all other variables are held constant. Blind experiments are often used, in which the researcher doesn’t know which group is treated until after the data have been analyzed. In health studies, such as tests of new drugs, double-blind experiments are used, in which neither the subject (who receives a drug or a placebo) nor the researcher knows who is in the treatment group and who is in the control group. 1-

1.6 A Brief History of Conservation and Environmental Thought 1-

Rising pollution levels led to the modern environmental movement The tremendous expansion of chemical industries during and after World War II added a new set of concerns to the environmental agenda. Silent Spring, written by Rachel Carson (fig. 1.24a) and published in 1962, awakened the public to the threats of pollution and toxic chemicals to humans as well as other species. 1-

Practice Quiz 1. Describe how fishing has changed at Apo Island, and the direct and indirect effects on people’s lives. 2. What are some basic assumptions of science? 3. Distinguish between a hypothesis and a theory. 4. Describe the steps in the scientific method. 5. What is probability? Give an example. 6. What does significance mean in statistics? 7. What’s the first step in critical thinking according to table 1.4? 8. Distinguish between utilitarian conservation and biocentric preservation. Name two environmental leaders associated with each of these philosophies. 9. Why do some experts regard water as the most critical natural resource for the twenty-first century? 10. Where in figure 1.7 do the largest areas of persistence of greening occur? What is persistence of greening? 11. Describe some signs of hope in overcoming global environmental problems. 12. What is the link between poverty and environmental quality? 13. Define sustainability and sustainable development. 1-

Chapt01 Lecture

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