a) Currently, about 10% of the radiative
energy from the earth escapes directly to
space, but as greenhouse gas emissions
increase, that fraction is expected to
decrease. If greenhouse gas emissions
result in 99% of the earth's radiation (E = \sigma T^4 where \sigma = 5.67x10^{-8} W/m^2/K^4) being
absorbed by the atmosphere, what will
happen to the radiative balance and the
temperature of the earth? To do this, we
will use the diagram at right. Write steady-
state energy balances for the earth and
space, including radiative fluxes (sun,
earth, atmosphere) and convective and evaporative fluxes (24 and 78 W/m$^2$) as shown at right.
The incoming solar energy (342 W/m$^2$) is absorbed, transmitted, and reflected by the
atmosphere. The atmosphere radiates more to earth than to space such that A is 1.5 times B.
Solve for B, then solve for E and the earth's surface temperature T. Also, what was the ratio
of A to B in problem 5.
Earth energy balance eq:
Space energy balance eq:
B: ____ W/m$^2$
E: ____ W/m$^2$
T: ____ K
A/B: ____
