While people are often understandably focused on what nuclear war would mean for humans, both the direct and indirect consequences would also be devastating for wildlife, plants and entire ecosystems. The current impacts of nuclear testing and production do not compare to the climatological disaster that would follow even a “limited” nuclear war. 

For decades, scientists have warned of and modelled the climate disruption that would follow any nuclear conflict.  After the explosion, smoke and dust from firestorms would block sunlight from reaching the Earth’s surface and cause an abrupt drop in global temperatures and rainfall, leading to shorter growing seasons and decreasing overall agricultural production and fish stocks worldwide. The launch of just 100 Hiroshima-sized nuclear weapons — less than 10% of global arsenals — would release 5 billion kilograms of soot into the upper atmosphere, spreading globally and staying there, and rapidly cool the planet. 

A nuclear winter would not reverse the effects of global warming. The changes in surface temperature, solar radiation and precipitation, would exacerbate some effects, including ocean acidification and damage to the ozone layer. Recent studies modeling the potential climate effects of nuclear war using crop yields, marine fishery and livestock production as indicators, found that production levels across the board would drop catastrophically, leading to global famine.

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