“Heat” from the sun that we feel is mostly IR/Visible light. Mix of stuff happens if we reflect it with white surfaces. Some of it does go back into space. Some

“Heat” from the sun that we feel is mostly IR/Visible light. Mix of stuff happens if we reflect it with white surfaces. Some of it does go back into space. Some of it will get reflected by the atmosphere back towards the ground. IR light is also directly absorbed by the air molecules, but very little. Air is mostly transparent at visible wavelengths so it absorbs very little energy. Solids are much better at converting IR to thermal energy. Realistically air conditioning is just moving heat from one side of a wall to another. Overall painting buildings white won’t change the temperature of Earth, but it does help the building in question, which is all air conditioning cares about anyways.