Sabres are rattling again in Washington towatd Moscow and Beijing. Could nuclear war still happen? The US and Russia possess about 14,000 nuclear warheads, but other countries possess them too, like India, Pakistan, Israel.
According to simulations by Alan Robock of Rutgers University in New Jersey and Michael Mills at the National Center for Atmospheric Research in Boulder, Colorado even a nuclear war between say India and Pakistan could devastate the world. The fires from bombed cities would send about 5 million tonnes of hot black smoke into the stratosphere, where it would spread round the world. This smog would cut solar radiation reaching Earth’s surface by 8 per cent – enough to drop average winter temperatures by a startling 2.5 to 6 °C across North America, Europe and much of Asia, and not just for a few days. It would take around five years for the impacts to peak, and the repercussions would still be felt strongly after a decade.
Near-ice-age temperatures would cause frosts capable of reducing the growing season in the world’s mid-latitude bread baskets by up to 40 days. This, combined with meagre rainfall and blistering UV, would cause crop yields to plummet. Nuclear winter would deliver global famine. The smoke would also heat the normally chilly stratosphere by around 30°C, unleashing nitrogen chemistry that would destroy much of the ozone layer.
Moreover, climate models predict that rainfall would be reduced as weather systems lost energy. The Asian monsoon would collapse... that’s two billion people with as much as 80 per cent less water. The Amazon basin and the already arid Southwestern US and western Australia would scarcely do better. All from a small regional but nuclear war.
Steven Starr of the University of Missouri has calculated that a nuclear exchange between the major nuclear powers, US and Russia (and perhaps China), could throw 150 million tonnes of smoke into the air. That would block 70 per cent of sunlight and cool much of the world by 20°C or more. Unable to grow food, most people would starve to death. Those who hope to hide from the starvation in deep bunkers or whatever will have a long wait for the radioactice fallout from such a massive nuclear exchange to reduce--thousands of years, and it is unlikely anyone could survive. One of the greatest geopolitical achievements of the past 60 years was to avoid a nuclear war. The next 60 look just as gloomy.
(Adapted from Fred Pearce, New Scientist)