Negative
Feedback Mechanisms
Negative
feedback mechanisms affect Earth's climate by maintaining the planet's
environmental balance. Below are examples of negative feedback mechanisms
that control precipitation and temperatures on Earth.
Elevated
concentrations of CO2 in the atmosphere result in more evaporation
from oceans. Increased evaporation from oceans causes the formation
of clouds that produce rain. The rain dissolves atmospheric CO2 and
carries it down to Earth's oceans, thereby decreasing the concentration
of CO2 in the atmosphere.
Photo:
Due to heavy cloud cover, the only landmasses visible to the Apollo
13 crew as they approach Earth are the southwestern United States and
northwestern Mexico. Photo courtesy of NASA's Johnson Space Center.
Increased dust
in the atmosphere blocks the incoming solar radiation, this results
in increased cooling of Earth. Increased cooling of Earth causes polar
ice caps to grow and sea level to drop. When the dust settles on polar
ice caps, the reflective capabilities of the ice decreases and the ice
absorbs more of the sun's energy. This causes the ice to melt and ultimately
results in a rise in sea level.
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