In this chapter and throughout this book, you will read about many cases in which humans have caused serious environmental problems. You will also read about promising, exciting solutions to many of these problems. Your task as a student of environmental science is to gain an idea of what some of the larger current problems are, what some solutions might be, and how you might use knowledge from a variety of disciplines—from biology and chemistry to economics—to develop tomorrow’s strategies for more sustainable living on our planet.
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.
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.
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.
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.
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.
Understanding probability helps reduce uncertainty
Probability is a measure of how likely something is to occur.
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.