8.10 Feedback Loops and Climate 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.

8.10 Feedback Loops and Climate 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 albedo effect Figure 3 The albedo effect is the relationship between ice and Earth’s temperature.