It’s all to do with Aerosols. In the atmosphere, aerosols in general, block the sun’s radiation from reaching the Earth. Aerosols are actually small particles or droplets, that float in the air. They come in many forms, both natural and industrial and include, sea salt, mineral dust, ash, sulphates, nitrates and black carbon (soot). So we are talking about wildfire smoke, volcanic gases, and many human activities. Soot has a warming effect but this is well overshadowed by the cooling effect of the other aerosols. In fact no one has taken much note of the cooling effect of aerosols, but scientists lately have found that their cooling effect may be greater than realised.
