Page 82 - Earth's Climate Past and Future

58 PART II • Tectonic-Scale Climate Change

tropics. A hard freeze is difficult to achieve because the 4. What evidence suggests that Earth always had a
large amount of solar heat stored in the ocean at low long-term thermostat regulating its climate?
latitudes tends to keep the surface free of ice.
5. Why is volcanic input of CO to Earth’s
2
atmosphere a poor candidate for a thermostat?
Key Terms
6. What climate factors affect the removal of CO
2
greenhouse era (p. 43) chemical weathering from the atmosphere by chemical weathering?
icehouse era (p. 43) thermostat (p. 51) 7. Where did the extra CO from Earth’s early
albedo (p. 44) water vapor feedback atmosphere go? 2
longwave radiation (p. 44) (p. 53) 8. What arguments support and oppose the Gaia
faint young Sun paradox Gaia hypothesis hypothesis that life is Earth’s true thermostat?
(p. 45) (p. 53)
thermostat (p. 46) snowball Earth 9. If Earth’s surface froze solid, what would happen
hypothesis (p. 57) to CO emissions from volcanoes and to CO
silicate minerals (p. 48) 2 2
removal by chemical weathering?

Additional Resources
Review Questions
Basic Reading
1. Why is Venus so much warmer than Earth Companion Web site at www.whfreeman.com/
today? ruddiman2e, pp. 2–3, 30–33.
Kastings, J. F., O. B. Toon, and J. B. Pollack. 1988.
2. What factors explain why Earth is habitable “How Climate Evolved on the Terrestrial Planets.”
today?
Scientific American (February), 90–97.
3. What is the faint young Sun paradox? Advanced Reading
Lovelock, J. 1995. The Ages of Gaia: A Biography of
Our Living Earth. New York: Norton.