A recent study by Physicians for Social Responsibility (PSR) has stated that an India-Pakistan nuclear war may see the use of about 100 Hiroshima-size bombs – about half of India and Pakistan’s nuclear arsenals.

A new study says that a nuclear exchange on such a scale would “probably cause the end (of) modern industrial civilisation as we know it” by subjecting about two billion people to the risk of starvation, and causing massive economic and social disruptions far away from the theatre of war. Among the consequences of a nuclear exchange: Chinese winter wheat production could decline by 50 per cent during the first year and by more than 30 per cent over ten years; there would be a 21 per cent decline in Chinese middle-season rice production during the first four years and an average 10 per cent decline in the following six years; corn and soybean production in the United States would decline by 10 per cent on average for ten years.

The 2012 study by PSR predicted that an India-Pakistan nuclear war could put more than one billion people at risk of starvation. The more recent study, released last month, adjusts this figure and calculates that an India-Pakistan nuclear war would put more than two billion people at risk. The updated analysis includes a study that shows that Chinese winter wheat production could decline by 50 per cent during the first year and by more than 30 per cent over ten years. Increasing crop prices due to a reduction of supply would worsen food shortages.

“Significant, sustained agricultural shortfalls over an extended period would almost certainly lead to panic and hoarding on an international scale as food exporting nations suspended exports in order to assure adequate food supplies for their own populations,” the report says. “This turmoil in the agricultural markets would further reduce accessible food.”

The chain of events which would lead to the catastrophe described in the report begins with firestorms caused by nuclear detonations. These detonations would send more than six million tonnes of soot into the atmosphere, shutting out sunlight and creating a global cooling effect scientists call “nuclear winter.”