Positive
and Negative Feedbacks
¥Assume that the Earth is warming.
-
Warming leads to more evaporation from oceans, which
increases water vapor in atmosphere.
-More water vapor increases absorption of IR, which
strengthens the greenhouse effect.
-This raises temperatures further, which leads to more
evaporation, more water vapor, warmingÉÒRunaway
Greenhouse EffectÓPositive Feedback Mechanism