Question

Which of the following is true concerning the balance between the solar energy absorbed and radiated by Earth?
a.
Earth’s atmosphere absorbs a larger fraction of total solar energy than it radiates.
b.
More than 90% of the solar energy that strikes Earth is absorbed.
c.
Earth’s surface is responsible for absorbing a larger fraction of energy than it radiates.
d.
None of the above.


Please select the best answer from the choices provided

A
B
C
D

Answer 1

D

None of the statements is correct. About 30% of incoming solar radiation is reflected (so ~70% is absorbed, not >90%). The atmosphere absorbs less solar energy than the surface and it emits more longwave radiation than it directly absorbs of solar. The surface absorbs roughly 168 W/m2 of solar but emits about 396 W/m2 in longwave (balanced by back radiation and nonradiative fluxes), so the surface does not absorb more than it radiates.