Determine the percentage of sunlight that is absorbed by atmospheric CO2 at a wavelength of λ = 4.85 μm. Assume that the sun is directly overhead, such that the sunlight travels the shortest distance through the atmosphere. The absorption cross section of CO2 at wavelength λ = 4.85 μm is 3.21 ·10-22 cm2 molecule-1. There is a total mass of 3.00 ·1015 kg of CO2 in the atmosphere and Earth's radius is 6,731 km.