Nuclear War Would Be More Devastating for Earth’s Climate Than Cold War Predictions – Even with Fewer Weapons

At the height of the arms race in the mid-1980s there were over 65,000 nuclear weapons. The reduction in the global nuclear arsenal to just over 12,000 (of which 4,000 are on operational standby) has ebbed the threat of all-out nuclear war, prompting some to question whether the limited climate models used in the 1980s had understated the consequences of a global nuclear war.

Newer and more sophisticated climate models, the ones used to model future climate changes caused by the burning of fossil fuels, suggest the opposite is true.

With the largest possible nuclear exchange between the US and Russia, new models suggest the ocean would cool so profoundly that the world would be thrust into a “nuclear little ice age” lasting thousands of years.

Of course, there are seven other nuclear states: China, France, India, Israel, North Korea, Pakistan and the UK. Scientists have modelled that even a limited nuclear war  between India and Pakistan could kill 130 million people and deprive a further 2.5 billion of food for at least two years.

A nuclear war is unlikely to remain limited, however. What starts with one tactical nuclear strike or a tit-for-tat exchange between two countries could escalate to an all-out nuclear war ending in utter destruction. A global nuclear war including the US, Europe and China could result in 360 million people dead and condemn nearly 5.3 billion people to starvation in the two years following the exchange.

The Threat Remains
Scientific modelling allows us to peer into the abyss of a nuclear war without having to experience it. Forty years of scientific research into these possibilities encouraged the adoption of a United Nations treaty on the prohibition of nuclear weapons in 2017 – ratified by most countries but not the nine nuclear powers.

The international campaign to abolish nuclear weapons was awarded a Nobel Peace Prize that same year for its work in highlighting the catastrophe that would result from any use of nuclear weapons.

But the war in Ukraine has brought old fears to the surface. President Vladimir Putin of Russia has threatened a limited use of nuclear weapons as part of the conflict, and a single launch could escalate into a regional or even global exchange that would plunge billions of people into a world so harrowing we can barely comprehend it.

Robock said that it is now “even more urgent” for scientists to study the consequences of detonating nuclear weapons and ensure as many people as possible know about them. And, ultimately, to work for the elimination of these weapons. The threat of nuclear war has not gone away, and a nuclear ice age which would doom much of life on Earth for millennia is still a possibility.

Mark Maslin is Professor of Earth System Science, UCL. This article is published courtesy of The Conversation.