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.

Image of the planet Earth with heavy cloud cover.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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Last updated April 28, 2005

Some images 2004

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