Some of it is scattered back into space by clouds and scattered from molecules in the atmosphere. Some of that which is scattered by clouds and molecules still reaches the Earth. This value varies greatly according to cloud cover, latitude, etc. The amount of heat transferred in divided by the temperature change. Energy of sunlight is more concentrated near the equator.
Hadley cells serve to diffuse heat away from equatorial regions.
Exponential Growth Rate of change of something is proportional to number of something. U.S. energy consumption per person triples between 1850-1990. Exothermic oxidation reactions. Domestic production of fossil fuels peaked in 1970. Hence, only certain energies absorbed or emitted by atoms or molecules.