Any nuclear war would return us to an ice age climate

July 7. () –

Any kind of conflict with nuclear weapons, even on a regional scale, would release soot and smoke into the upper atmosphere that it would block out the Sun and cause global crop failure.

In the first month after the nuclear detonation, average global temperatures would drop by about 7 degrees Celsius, a greater temperature change than in the last Ice Agereveals a study led by Louisiana State University (LSU).

“It doesn’t matter who’s bombing who. They can be India and Pakistan or NATO and Russia. Once the smoke is released into the upper atmosphere, it spreads globally and affects everyone,” said it’s a statement LSU Department of Oceanography and Coastal Sciences assistant professor Cheryl Harrison, lead author of the research, published in AGU Advances.

Ocean temperatures would drop rapidly and would not return to their pre-war state even after the smoke cleared. As the planet cools sea ​​ice expands by more than 9 million square kilometers and 2 meters deep in some basins that block the main portsports, including the port of Tianjin in Beijing, Copenhagen and St. Petersburg. Sea ice would spread to normally ice-free coastal regions blocking shipping in the Northern Hemisphere, making it difficult to ship food and supplies to some cities like Shanghai, where ships are not prepared to deal with sea ice.

The sudden drop in light and ocean temperatures, especially from the Arctic to the North Atlantic and North Pacific oceans, would kill off seaweed, which is the base of the marine food web, essentially creating an ocean famine. This would stop most fishing and aquaculture.

The researchers simulated what would happen to Earth’s systems if the US and Russia used 4,400 100-kiloton nuclear weapons to bomb cities and industrial areas, resulting in fires that spewed 150 teragrams, or more than 150 billion kilograms, of sunlight-absorbing black carbon smoke into the upper atmosphere. They also simulated what would happen if India and Pakistan detonated around 500 100-kiloton nuclear weapons that would spell 5 to 47 teragrams, or 5 to 10.3 billion kilograms, of smoke and soot into the upper atmosphere.

“Nuclear warfare has 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 at the United Nations to ban nuclear weapons.” 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.

This study shows the global interconnectedness of Earth’s systems, especially in the face of disturbances, whether caused by volcanic eruptions, massive forest fires, or wars.

“The current war in Ukraine with Russia and how it has affected gas prices really shows us how fragile our global economy is. and our supply chains in the face of what may appear to be regional conflicts and disruptions”Harrison said.

Volcanic eruptions also produce clouds of particles in the upper atmosphere. Throughout history, these eruptions have had similar negative impacts on the planet and civilization.

“We can prevent a nuclear war, but volcanic eruptions will definitely happen again. There’s nothing we can do about it, so it’s important when we talk about resilience and how to design our society, that we consider what we need to do to prepare for those. unavoidable climate impacts,” Harrison said. “We can and must, however, do everything possible to prevent a nuclear war. The effects are very likely to be globally catastrophic.“.

The oceans take longer to recover than the land. In the larger US-Russia scenario, ocean recovery is likely to take decades on the surface and hundreds of years in the depths, while changes in Arctic sea ice are likely to last thousands of years and are effectively a “Little Nuclear Ice Age”. Marine ecosystems would be highly altered both by the initial disturbance and by the new state of the ocean, which would lead to long-term global impacts on ecosystem services such as fisheries, the authors write.