The soot particles make the color of that part of the planet into a lighter color. In planet science, this is known as 'albedo.' A lighter albedo increases the

The soot particles make the color of that part of the planet into a lighter color. In planet science, this is known as 'albedo.' A lighter albedo increases the amount of solar rays which are reflected into space. There are proposals to use this to reduce warming, of varying seriousness. It's seen as a rather extreme measure though: https://www.bbc.com/future/article/20190220-how-artificially-brightened-clouds-could-stop-climate-change https://www.bbc.com/future/article/20190220-how-artificially... That all said, the degree of cooling predicted by nuclear theorists was overstated—not that overstating the destructiveness of nuclear weapons is so bad: https://www.nytimes.com/1990/01/23/science/nuclear-winter-theorists-pull-back.html https://www.nytimes.com/1990/01/23/science/nuclear-winter-th...