I got wondering about this while waiting for a bus.
We know that large volcanic explosions such as the Mount Tambora eruption have led to cooling due to ash, etc, in the atmosphere. We also know that increasing levels of carbon dioxide increase the heat retention of the atmosphere, leading to warming.
During WW2, there was a lot of industrial activity, plus actual fighting and burning cities, which presumably led to increased pollution and smoke and carbon dioxide emissions. Do we know whether this had any global effect of the earth’s climate?