Light turns into heat when it is absorbed by a material. Reflecting it back into the air sends it (and the heat) back out into space, and since air is mostly cl

Light turns into heat when it is absorbed by a material. Reflecting it back into the air sends it (and the heat) back out into space, and since air is mostly clear it does not get absorbed so doesn’t “heat up the planet”, at least not in any significant way. Sure, using the energy for solar would be nice too, but that’s far more expensive per square meter, so paint is a fine solution that’s cheap.