https://www.vice.com/en_us/article/y3pw9k/a-nuclear-war-between-the-us-and-russia-would-starve-5-billion-people

The worst part of nuclear war is surviving it. Millions would die in a nuclear exchange between superpowers like Russia and the U.S., but billions more would die in the aftermath of even a “limited” nuclear war. That’s the takeaway from a new study published in Nature Food that models the effects of nuclear war on the global food supply.

The prediction is dire. “We estimate more than 2 billion people could die from nuclear war between India and Pakistan, and more than 5 billion could die from a war between the United States and Russia—underlining the importance of global cooperation in preventing nuclear war,” the study said.