1. Calculate the surface temperature on Mars in the absence ofgreenhouse warming. Recall thatT=[F_S(1-A)/4S]^1/4 in the absence ofgreenhouse warming. The “solar constant” at Mars’ distance from theSun is roughly 620 Wm^-2; assume an albedo of 0.25. Heresigma(S) is the Stefan-Boltzmann constant.

2. Calculate the percent increase in transmission of light at 285 nm for a 1%decrease in the thickness of the ozone layer. Assuming anequivalent thickness of 0.34 cm before the decrease, and anextinction coefficient of 56 cm^-1 at285 nm, the percent increase in transmission of light at 285 nm fora 1% decrease in the thickness of the ozone layer is:

3.  The fraction of radiation emitted by theEarth’s surface that is absorbed by the atmosphere, f, is 0.77(i.e., 77%). The other 23% of this energy is emitted directly tospace. What fraction of the radiation that the Earth receives fromthe Sun is ultimately emitted back to space?