File:Figure 2.1 Global average energy budget of Earth’s atmosphere (6080398732).jpg

This image is excerpted from a U.S. GAO report: <a href="http://www.gao.gov/products/GAO-11-71" rel="nofollow">www.gao.gov/products/GAO-11-71</a>

Note: All numeric values are in watts per square meter (W/m2). Incoming sunlight is both reflected from and absorbed by the atmosphere, clouds, and Earth’s surface. Some of the energy absorbed by Earth’s surface is transferred to the atmosphere by evaporation and convection, and the remainder is emitted as heat energy. The majority of the heat energy is absorbed by the atmosphere and clouds, with some escaping directly to space. Energy absorbed by the atmosphere and clouds is reradiated as heat energy back to Earth’s surface as well as directly to space. Based on the composition of the atmosphere and clouds, the heat energy they absorb can accumulate by the greenhouse effect in which energy emitted from Earth’s surface is trapped by gases in the atmosphere and clouds. For this reason, greenhouse gases in Earth’s atmosphere can affect global average surface temperature. (An animated depiction of the global average energy budget of Earth’s atmosphere may be viewed at <a href="http://www.gao.gov/multimedia/interactive/GAO-11-71b.)" rel="nofollow">www.gao.gov/multimedia/interactive/GAO-11-71b.)</a>