“Even after the smoke clears, ocean temperatures would drop quickly and would not return to their pre-war state. As the planet gets colder, sea ice expands by more than 6 million square miles and 6 feet deep in some basins blocking major ports including Beijing’s Port of Tianjin, Copenhagen, and St. Petersburg. The sea ice would spread into normally ice-free coastal regions blocking shipping across the Northern Hemisphere making it difficult to get food and supplies into some cities such as Shanghai, where ships are not prepared to face sea ice.
The sudden drop in light and ocean temperatures, especially from the Arctic to the North Atlantic and North Pacific oceans, would kill the marine algae, which is the foundation of the marine food web, essentially creating a famine in the ocean. This would halt most fishing and aquaculture.
The researchers simulated what would happen to the Earth’s systems if the U.S. and Russia used 4,400 100-kiloton nuclear weapons to bomb cities and industrial areas, which resulted in fires ejecting 150 teragrams, or more than 330 billion pounds, of smoke and sunlight-absorbing black carbon, into the upper atmosphere. They also simulated what would happen if India and Pakistan detonated about 500 100-kiloton nuclear weapons resulting in 5 to 47 teragrams, or 11 billion to 103 billion pounds, of smoke and soot, into the upper atmosphere.
“Nuclear warfare results in dire consequences for everyone. World leaders have used our studies previously as an impetus to end the nuclear arms race in the 1980s, and five years ago to pass a treaty in the United Nations to ban nuclear weapons. We hope that this new study will encourage more nations to ratify the ban treaty,” said co-author Alan Robock, Distinguished Professor in the Department of Environmental Sciences at Rutgers University.”