DR+ch+23+hw

Chapter 23 Human Interference (WIki) Last Unit...Life with us.

Human Interference with the water cycle (p.499) 1. What are the three ways humans disrupt the natural water cycle? a. they withdraw water b. They clear vegetation from land c. they interfere with the natural processes that purify water

2. What is groundwater mining and what is the danger of this process? When withdrawals of water exceed any possibility of recharge. We may run out of freshwater

3. Why is it possible to run out of freshwater, a renewable resource? When the available supply runs off instead of entering bodies of freshwater and aquifiers

Human Interference with the carbon cycle (p.501) 1. How are humans increasing the amount of carbon dioxide being deposited in the atomosphere on top of "natural" sources? Humans are burning fossil fuels

2. What are the greenhouse gases and what are the human causes of these gases? Carbon dioxide, nitrous oxide, and methane

3. Why are these gases called greenhouse gases? Because they allow solar radiation to enter but heat cannot escape back into space

4. What are some possible dangers of global warming? Sea levels will rise

Human Interference with the Ozone Shield (p.506) 1. What is the ozone shield and what chemical reaction produces ozone? The ozone shield is the shield in the stratosphere that protects the earth from uv rays.

2. What are ozone holes? Severe depletions of the ozone layer

3. Why are ozone holes dangerous to humans? They will cause an increase in cataracts and skin cancer

4. What human pollution destroys ozone molecules? Chlorine atoms

5. What are commons sources of chlorine pollution? The breakdown of chlorofluorocarbons Human Interference and the Arctic (p. 507) 1. What does ANWR stand for and what is it? Artic National Wildlife Refuge

2. Why is ANWR the source of political debate? Because the value of wildlife is measured against the value of natural resources

3. What are the benefits of drilling for oil in ANWR? It would establish new jobs and bring in money to the economy

4. What are the risks of drilling for oil in ANWR? It would hurt the wildlife.