Question

To a rough approximation, the Earth can be treated as a greybody sphere with uniform temperature, absorptance ? = 0.70 and emissivity ? = 0.61. The low absorptance is largely due to reflection of the incoming sunlight by clouds and ice, while the low emissivity is largely due to greenhouse gases in the atmosphere.

a) Over timescales of decades, the total solar irradiance at the Earth varies between about 1360.3 W/m² and 1362.0 W/m² . Using the greybody Earth approximation, how large of a temperature change can be expected due to these natural changes in solar irradiance? [Answer in K as a positive number.]

b) Over the last century, the amount of CO2 in the atmosphere has increased dramatically, which has resulted in a change in ? from 0.62 to 0.61. Using the greybody Earth approximation, how large of a temperature change can be expected due to this change in emissivity? [Answer in K as a positive number.]

NOTE: The answers to a) and b) are NOT 0.1 K

Answer 1