Final answer:
On average, about 50 percent of the incident solar energy is absorbed by the Earth's surface. The rest is either reflected back into space or absorbed in other ways contributing to various processes on the planet.
Step-by-step explanation:
About 50 percent of the incident solar energy is absorbed by the Earth. The sun delivers roughly 1,360 W/m² to the top of the Earth's atmosphere, and approximately 29.3% of this is reflected back to space by clouds, snow, and other surfaces. This leaves approximately 70.7% of the light to be absorbed by the Earth. However, when accounting for the projected area presented to the sun compared to the total surface area of the Earth, we find that, on average, only about 50 percent of the incoming solar energy is absorbed by the Earth's surface.
Energy balance is maintained by the fact that, in perfect equilibrium, the energy absorbed by the Earth (which includes direct thermal absorption, evaporation of water, wind, photosynthesis, and ocean currents) equals the infrared radiation emitted back into space.