Feedback Loops and Climate 8 10 Small changes

Feedback Loops and Climate 8. 10 • Small changes are sometimes made bigger by feedback loops. Feedback loops can also work the opposite way and make changes smaller. • Water Vapour Feedback Loop: More water vapour enters the atmosphere when the climate warms up. Water vapour is a greenhouse gas, so its presence causes the climate to warm up even more. Conversely, if the climate cools down, less water vapour forms and the climate cools further. • Low Clouds Feedback Loop: Low clouds trap thermal energy near Earth’s surface. As Earth warms, more clouds form. • High Clouds Feedback Loop: High clouds reflect the Sun’s radiation back out to space, resulting in cooler temperatures and fewer clouds.

Feedback Loops and Climate 8. 10 The Albedo Effect • The proportion of radiation reflected by a surface is called its albedo. For example, ice has a high albedo because it reflects back most of the Sun’s radiation. • The albedo effect is a feedback loop between ice on Earth’s surface and Earth’s average temperature. • If Earth’s average temperature drops slightly, more ice forms. This ice reflects more of the Sun’s radiation, and Earth’s temperature decreases even more. • If Earth’s average temperature increases slightly, more ice melts. More of the Sun’s radiation is absorbed, and Earth’s temperature increases even more. albedo effect Figure 3 The albedo effect is the relationship between ice and Earth’s temperature.