Consequences of nuclear war
Atmospheric Science
The likely catastrophic environmental effects of global nuclear war are well-described in the scientific literature, but the effects of a more limited, regional nuclear war are also staggering. Toon et al. combined a realistic war scenario involving the neighboring, nuclear-capable nations of India and Pakistan with established climate models to explore plausible global effects of such conflict. These models suggest that, in addition to human casualties, an India-Pakistan nuclear war would start fires releasing tens of trillions of grams of black carbon into the stratosphere. Distributed globally, this soot would limit the amount of sunlight that reaches Earth's surface, drastically reducing surface temperatures and thus potentially limiting food supplies globally for more than a decade.

Sci. Adv. 10.1126/sciadv.aay5478 (2019).