Nation special report

LONDON: In wake of severely tense relations between Pakistan and India, the American researchers of two prominent universities have expressed apprehension that a nuclear war between the two neighbour countries could kill more than 125 million people ‘immediately’.

Renewed tensions between the two South Asian countries has led to scientists at Rutgers University to predict what could happen if the two powers declared war in a paper published on Wednesday.

The scenario, modelled by researchers, envisaged more than 100 million immediate deaths, followed by global mass starvation after megatons of thick black soot blocked out sunlight for up to a decade. 

The death toll, however, could rise to 125 million if both countries expended the bulk of their highest yield weapons and put into use powerful 100 kiloton weapons. India and Pakistan currently each have around 150 nuclear warheads at their disposal, with the number expected to climb to more than 200 by 2025. 

It comes at a time of rising tensions between the rivals, who have fought several wars over the Muslim-majority territory of Kashmir.  ‘Unfortunately it’s timely because India and Pakistan remain in conflict over Kashmir, and every month or so you can read about people dying along the border,’ said Rutgers University professor Alan Robock, who co-authored the paper in Science Advances.

India has a ‘no first strike’ policy, but reserves the right to mount a nuclear response to any hit by weapons of mass destruction. Pakistan has declared it would only use nuclear weapons if it could not stop an invasion by conventional means or if it was attacked first with nuclear weapons.

The authors wrote that although their scenario had Pakistan pulling the trigger first, they did not mean to imply they believed this was more likely. Based on their current populations and the urban centers that would be likely targeted, the researchers estimated up to 125 million could be killed if both countries expended the bulk of their highest yield weapons. This most extreme scenario would involve the use of 100 kiloton weapons, more than six times as powerful as the bombs dropped on Hiroshima.

A single airburst from such a bomb could kill two million people and injure 1.5 million – but most of the deaths would occur from the raging firestorms that followed the blast.

‘India would suffer two to three times more fatalities and casualties than Pakistan because, in our scenario, Pakistan uses more weapons than India and because India has a much larger population and more densely populated cities,’ the paper said.

As a percentage of its urban population, though, Pakistan’s losses would be about twice those of India. But nuclear Armageddon would be only the beginning.

The research found that the firestorms could release 16 million to 36 million tons of soot (black carbon) into the upper atmosphere, spreading around the world within weeks. The soot in turn would absorb solar radiation, heating the air up and boosting the smoke’s rise.

The study, published in the journal Science Advances, looked at a war scenario that may occur between India and Pakistan in 2025. While both the neighbouring countries have waged several wars over Kashmir, they could come to possess a combined count of 400 to 500 nuclear weapons by 2025, the study noted.

“They’re rapidly building up their arsenals. They have huge populations, so lots of people are threatened by these arsenals, and then there’s the unresolved conflict over Kashmir,” Toon said.

The researchers found that the exploding nuclear weapons could release 16 to 36 million tonnes of soot — tiny black carbon particles in smoke — that could rise to the upper atmosphere and spread around the world within weeks.

The soot, the researchers said, would absorb solar radiation, and heat up the air, boosting the smoke’s swift rise.

In the process, the study noted that the sunlight reaching the Earth would decline by 20 to 35 per cent, causing our planet’s surface to cool by 2 to 5 degrees Celsius.

Rainfall across the world may also reduce by 15 to 30 per cent, both of which could have larger regional impacts, the study noted.

The researchers added that vegetation growth would decline globally by 15 to 30 per cent on land, and the oceans could see a productivity decline by 5 to 15 per cent.

Overall, the study noted that recovery from all these impacts would take more than 10 years since the smoke would linger in the upper atmosphere.

“Nine countries have nuclear weapons, but Pakistan and India are the only ones rapidly increasing their arsenals,” Robock said.

He added that the continuing unrest between the two nuclear-armed countries, particularly over Kashmir, made it important to understand the consequences of a nuclear war.

According to the researchers, the nuclear weapons in the year 2025 could range from 15 kilotonnes in explosive power — the same size as the bomb dropped on Hiroshima by the US in 1945 — to a few hundred kilotonnes.

In the scenario, the researchers estimated that 50 to 125 million people could die from the direct effects, with additional deaths from mass starvation also possible worldwide. “Nuclear weapons cannot be used in any rational scenario but could be used by accident or as a result of hacking, panic or deranged world leaders,” Robock said. According to Robock, the only way to prevent accidental usage of nuclear weapons was to eliminate them.