The current magnitude of the greenhouse effect is measured by the
difference between the emission from the surface and the emission from the top of the
atmosphere,
€
G =σTs
4 −σTe
4 ≈ 150 W m-2. What would be the required magnitude of
the greenhouse effect to maintain the surface temperature at 288 K if the solar constant
were reduced by 30%? By what distance would the effective emission level of the
atmosphere need to rise if the lapse rate is approximately 6 K km-1?