With a global average irradiance of 342 W/m2, the Sun is by far the largest source of energy for planet Earth. In comparison, the internal energy produced by Earth itself is only about W/m2 (Pollack et al., 1993), which in turn is times larger than the W/m2 of heat produced by the burning of fossil fuels. About 31% (31 units) of the solar energy which arrives at the top of the atmosphere is reflected back to space by scattering from clouds, aerosols, and the Earth’s surface. Almost 20 units of solar radiation are absorbed in the atmosphere
