Global Famine after a Regional Nuclear War

Tuesday, 16 December 2014: 8:00 AM
Alan Robock, Rutgers University, New Brunswick, NJ, United States, Lili Xia, Rutgers Univ, New Brunswick, NJ, United States, Michael J Mills, National Center for Atmospheric Research, Boulder, CO, United States, Andrea Stenke, ETH Swiss Federal Institute of Technology Zurich, Zurich, Switzerland and Ira Helfand, International Physicians for the Prevention of Nuclear War, Somerville, MA, United States
A regional nuclear war between India and Pakistan, using 100 15-kt atomic bombs, could inject 5 Tg of soot into the upper troposphere from fires started in urban and industrial areas. Simulations by three different general circulation models, GISS ModelE, WACCM, and SOCOL, all agree that global surface temperature would decrease by 1 to 2°C for 5 to 10 years, and have major impacts on precipitation and solar radiation reaching Earth’s surface. Local summer climate changes over land would be larger. Using the DSSAT crop simulation model forced by these three global climate model simulations, we investigate the impacts on agricultural production in China, the largest grain producer in the world. In the first year after the regional nuclear war, a cooler, drier, and darker environment would reduce annual rice production by 23 Mt (24%), maize production by 41 Mt (23%), and wheat production by 23 Mt (50%). This reduction of food availability would continue, with gradually decreasing amplitude, for more than a decade. Results from simulations in other major grain producing regions produce similar results. Thus a nuclear war using much less than 1% of the current global arsenal could produce a global food crisis and put a billion people at risk of famine.