The threat of nuclear war is the hottest it's been since the Cold War, so a team of scientists has taken a fresh look into the endlessly bleak subject of what would happen if atomic bombs started flying in today’s world. As you can imagine, it’s pretty dreadful.
Reported in the journal AGU Advances, the study details how an atomic war involving exchanges between any of the world’s nine nuclear powers would result in colossal bellows of soot and smoke being pumped into the upper atmosphere. This would block out the Sun, sparking a 7.2°C (13°F) global temperature plunge within a month and eventual crop failure.
Oceans could become affected even more harshly, with the impacts of nuclear war lasting decades if not centuries, potentially plunging the world into a "Nuclear Little Ice Age".
Ocean temperatures would plummet, especially in northern parts of the world’s ocean, where the growing extent of sea ice would freeze up waters around major ports including Beijing’s Port of Tianjin, Copenhagen, and St. Petersburg, loading further strain on global trade.
The ocean’s big freeze and lack of Sun would result in the mass die-off of marine algae. Since this underpins much of the marine food web, the oceans would become starved, resulting in a near-total demise of fishing and aquaculture.
These catastrophic effects would be felt in all of the scenarios studied by the team. They could also be felt across the world, regardless of where in the world the bombs were denoted.
“It doesn’t matter who is bombing whom. 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,” Assistant Professor Cheryl Harrison, lead study author from Louisiana State University, said in a statement.
The new research saw scientists run a number of computer simulations to study the impacts of various nuclear warfare scenarios on the Earth’s systems given today’s nuclear warfare capabilities.
There are currently about 13,000 nuclear weapons in the world split between nine countries (although many of these warheads are technically "retired" and longer actively delayed). The overwhelming majority of warheads are in the hands of the US and Russia, while just over 1,000 are held by France, China, the UK, Pakistan, India, Israel, and North Korea.
One of the most important showdowns they envisioned was a nuclear exchange between the US and Russia. In one of these scenarios, they imagined Russia and US using 4,400 100-kiloton nuclear weapons against each other's major cities and industrial areas. This, they estimated, would result in fires ejecting 149 billion kilograms (330 billion pounds) of smoke and black carbon into the upper atmosphere.
Even if a smaller nuclear war took place between India and Pakistan, the impact would be global and catastrophic. In theory, these two countries could detonate about 500 100-kiloton nuclear weapons, creating up to 46 billion kilograms (103 billion pounds) of smoke and soot, which would also stop a vital amount of sunlight to reach the Earth.
All in all, the results of the study are clear: the planet needs to avoid nuclear war at all costs. Furthermore, given the global interconnectedness of Earth’s systems in the 21st century, the need to advert it has perhaps never been greater.
“The current war in Ukraine with Russia and how it has affected gas prices, really shows us how fragile our global economy and our supply chains are to what may seem like regional conflicts and perturbations,” Harrison added.
“We can and must […] do everything we can to avoid nuclear war. The effects are too likely to be globally catastrophic.”