US-Russia nuclear war would plunge the world into 10 years of darkness

If the US and Russia used up their current nuclear arsenals in war, the fires ignited by nuclear explosions could inject 150 Tg of soot into the upper troposphere and lower stratosphere, triggering a global nuclear winter. These soot aerosols would be carried all around the world by stratospheric winds in a matter of weeks, blocking out the sun and causing global average surface temperatures to plummet by more than 8 degrees. Their model suggests it would take seven years before we would see a significant dent in the black curtain covering the Earth, taking about 10 years after the start of the war to return to normal levels of light. The follow on climatic effects would also collapse the monsoon and dramatically shift El Niño variability.