In their study, earth scientist Professor Cheryl Harrison of Louisiana State University and her colleagues ran several models of the impact of nuclear warfare on the Earth’s system. They considered the effects on both a regional and larger scale – taking into account the current nuclear war capabilities of the nations of the world. Nine countries currently possess more than 13.00 nuclear weapons, according to the Stockholm International Peace Research Institute.
The researchers simulated the effects of a nuclear conflict between Russia and the US, with 4,400 100-kiloton bombs, and India and Pakistan, with 500 100-kiloton bombs.
In all their computer simulations, the team found that nuclear firestorms would release soot and smoke into the upper atmosphere, blocking the sun and leading to crop failures around the world.
In the US-Russia scenario, more than 330 billion pounds of sunlight-blocking black carbon would be placed in the upper atmosphere, while a conflict between India and Pakistan would produce 11-103 billion pounds of smoke and soot.
In addition, in the first month after the nuclear blast, Earth’s average temperature would drop by about 13F — a larger shift observed in the last ice age.
Prof Harrison said: “It doesn’t matter who is bombing who. It could be India and Pakistan or NATO and Russia.
“Once the smoke is released into the upper atmosphere, it spreads worldwide and affects everyone.”
According to the researchers, the wake of nuclear war would rapidly plummet the ocean’s temperature — and this would not return to its pre-conflict state even after the smoke clears.
As the planet cooled, the sea ice would expand by more than six million square miles, reaching six feet thick in some basins, blocking major ports — including Copenhagen, Saint Petersburg and Beijing’s Tianjin Port. In the worst cases, these changes can take thousands of years.
The combination of darkness and falling ocean temperatures would kill algae — especially in the Atlantic and North Pacific oceans.
Since algae are the foundation of the marine food web, this loss would cause a famine in the ocean, bringing aquaculture and fisheries to a standstill.
The team said their findings emphasize the interconnected nature of Earth’s systems.
Prof Harrison said: “The current war in Ukraine with Russia and how it has affected gas prices really shows us how vulnerable our global economy and our
supply chains are for what appears to be regional conflict and disruption.”
She added: “We can and must […] do everything they can to prevent a nuclear war.
“It is too likely that the effects will be catastrophic globally.”
The study’s full findings were published in the journal AGU Progress†