Write true if the statement is true or false if the statement is false.
1. _______ Air pollution is no longer a major problem in the U.S.
2. _______ Heart attacks may be triggered by pollutants in the air.
3. _______ Acid rain may kill animals but does not affect plants.
4. _______ Earth had no greenhouse effect until human beings started burning fossil
fuels.
5. _______ Outdoor air is always more polluted than indoor air.
6. _______ Air pollution is a major contributor to respiratory diseases.
7. _______ It is easier to control the quality of indoor air than outdoor air.
A major problem caused by air pollution is global climate change. Gases such as carbon dioxide
from the burning of fossil fuels increase the greenhouse effect and raise Earth’s temperature.
The greenhouse effect is a natural feature of Earth’s atmosphere. It occurs when certain gases
in the atmosphere, including carbon dioxide, radiate the sun’s heat back down to Earth’s
surface. Without greenhouse gases in the atmosphere, the heat would escape into space. The
natural greenhouse effect of Earth’s atmosphere keeps the planet’s temperature within a
range that can support life.
The rise in greenhouse gases due to human actions, especially the burning of fossil fuels, is too
much of a good thing. It increases the greenhouse effect and causes Earth’s average
temperature to rise. Rising global temperatures, in turn, are melting polar ice caps and
glaciers. With more liquid water on Earth’s surface, sea levels are rising.
Adding more heat energy to Earth’s atmosphere also causes more extreme weather and
changes in precipitation patterns. Global warming is already causing food and water shortages
and species extinctions. These problems will only grow worse unless steps are taken to curb
greenhouse gases and global climate change.
Questions
1. What is the natural greenhouse effect? Why is it important to life on Earth?
2. Explain why the greenhouse is effect greater now than in the past.
3. Discuss environmental consequences of the recent increase in the greenhouse effect.