Drop of 10ºC, extension of the polar ice and widespread famines, main consequences
The Russian invasion of Ukraine has brought the threat of nuclear war to the fore. But what would be the effects of a nuclear war over the planet? A new scientific study published in the journal AGU Advances provides detailed information on the global impact of such a catastrophe.
The lead author of the study, Cheryl Harrison, an assistant professor in the Department of Oceanography at Louisiana State University (LSU), USA, and colleagues performed multiple computer simulations to study the impacts of a nuclear war on Earth systems. , taking into account the characteristics of the current atomic arsenal. Nine nations currently control more than 13,000 nuclear weapons in the world.according to the Stockholm International Peace Research Institute.
As shown by the analyzed simulations, the firestorms that would trigger the nuclear explosions would release such quantities of soot and smoke into the upper atmosphere that they would block the Sun and cause the massive crop failure worldwide, leading to a major famine. In the first month after the nuclear detonation, the average global temperatures would drop by about 10.5 degrees Celsius, a drop greater than that recorded in the last Ice Age.
“It doesn’t matter who is bombing who. It can be India and Pakistan or NATO and Russia. Once the smoke is released into the upper atmosphere, it spreads globally and affects everyone,” Harrison warned.
Ocean temperatures would drop rapidly and would not return to their previous state even after the smoke cleared. As the planet cools sea ice would expand by almost 10 million square kilometers and 1.8 meters deep in some basins near major ports, including Beijing’s Tianjin Port, Copenhagen, and St. Petersburg.
Sea ice would spread to normally ice-free coastal regions, thereby blocking shipping in the Northern Hemisphere, would make it difficult to send food and supplies to some cities like Shanghai, where ships are unprepared to push through 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, creating what can be considered a ‘famine’ widespread in the ocean, which would leave most species without food. This situation it would wipe out almost all fishing and aquaculture.
In fact, the oceans take longer to recover than land. In the most dire scenario of a US-Russian confrontation, ocean recovery is likely to take decades at the surface and hundreds of years at depth, while changes in Arctic sea ice are likely to last thousands of years and lead to a ‘Little Nuclear Ice Age’.
The blackened atmosphere would block the arrival of sunlight
To reach these conclusions, 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. The result was widespread fires that would dump 150 teragrams, or more than 148.5 billion kilos of smoke and soot into the upper atmosphere. They also simulated what would happen if India and Pakistan detonated around 500 100-kiloton nuclear warheads: They would dump 5 to 47 teragrams, or 5 to 46 billion kilograms, of smoke and soot into the upper atmosphere.
“Nuclear war has dire consequences for everyone. World leaders used our studies previously as an impetus to end the nuclear arms race in the 1980s, and five years ago to pass a United Nations treaty to ban nuclear weapons. We hope 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 systems, especially in the face of large-scale disturbances, whether caused by volcanic eruptions, massive forest fires, or wars.
“The current war in Ukraine and how it has affected gasoline prices shows us how fragile our global economy and supply chains are in the face of regional conflict and disruption,” Harrison said.
Other catastrophic events, such as volcanic eruptions, also produce clouds of particles in the upper atmosphere. In fact, throughout history, these eruptions have had negative impacts similar to those of atomic explosions on the planet and civilization.
Harrison explained that little can be done to prevent a major volcanic eruption, but it can be done to stop a confrontation with atomic weapons. “We can and must do everything possible to prevent a nuclear war. The effects are very likely to be globally catastrophic.”
Reference study: https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2021AV000610
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