Why the earth neither warms up nor cools down despite the huge transfer of heat that takes place?

All the rest of the energy is absorbed in the atmosphere and in the earth. Since the efficiencies in the upward and downward fluxes differ in different places, it follows that some locations will be cooler than others.

The overall picture is one of a planet that is continuously being cooled from radiation from outer space to match the slowly increasing insolation. Consider that the insolation received at the top of the atmosphere is 100 per cent.

Roughly 35 units are reflected back to space even before reaching the earth’s surface. (27 units are reflected back from the top of the clouds and 2 units from the snow and ice-covered areas of the earth.)

The reflected amount of radiation is called the albedo of the earth. The remaining 65 units are absorbed (14 units within the atmosphere and 51 units by the earth’s surface).

The earth radiates back 51 units in the form of terrestrial radiation. Of these, (17 units are radiated to space directly and the remaining 34 units are absorbed by the atmosphere

48 units absorbed by the atmosphere (14 units from insolation +34 units from terrestrial radiation) are also radiated back into space).

Thus, the total radiation returning from the earth and the atmosphere respectively is there are variations in the amount of radiation received at the earth’s surface.