Atmosphere Ocean Science Colloquium

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Nuclear Famine: The Threat to Humanity from Nuclear Weapons

Speaker: Alan Robock, Rutgers University

Location: Warren Weaver Hall 1302

Date: Wednesday, October 7, 2015, 3:30 p.m.

Synopsis:

A nuclear war between any two nations, with each county using 50 Hiroshima-sized atom bombs as airbursts on urban areas, would inject so much smoke from the resulting fires into the stratosphere that the resulting climate change would be unprecedented in recorded human history. Climate model simulations find that the smoke would absorb sunlight, making it dark, cold, and dry at Earth's surface and produce global-scale ozone depletion, with enhanced ultraviolet (UV) radiation reaching the surface. The erythemal dose from the enhanced UV radiation would greatly increase, in spite of enhanced absorption by the remaining smoke, with the UV index more than 3 units higher in the summer midlatitudes, even after a decade.

Scenarios of changes in temperature, precipitation, and downward shortwave radiation from the GISS ModelE, Swiss SOCOL, and NCAR WACCM climate model simulations, applied to the Decision Support system for Agrotechnology Transfer and Community Land Model crop models show that these perturbations would reduce global agricultural production of the major food crops by 10-40% for a decade. The impact the nuclear war simulated here, using much less than 1% of the global nuclear arsenal, could sentence a billion people now living marginal existences to starvation.

The greatest nuclear threat still comes from the United States and Russia. Even the reduced arsenals that will remain in 2017 after the New START treaty threaten the world with nuclear winter. The world as we know it could end any day as a result of an accidental nuclear war between the United States and Russia. With temperatures plunging below freezing, crops will die and massive starvation could kill most of humanity. The environmental and humanitarian impacts of the use of even a small number of nuclear weapons must be considered in nuclear policy deliberations.