Cooperative Institute for Research in Environmental Sciences

Distinguished Lecture Series: Dr. Alan Robock

Distinguished Lecture Series: Dr. Alan Robock

Title: "Climatic and Humanitarian Impacts of Nuclear War"

Abstract:  A nuclear war between any two nations, such as India and Pakistan, with each country 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.  Our 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 changes in temperature, precipitation, and sunlight from the climate model simulations, applied to crop models show that these perturbations would reduce global agricultural production of the major food crops by 10-40% for a decade.  The impact of 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 remain in 2018 due to 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 would die and massive starvation could kill most of humanity.

            I will describe a new project being conducted jointly with scientists from the University of Colorado and NCAR, which is examining in detail, with city firestorm and global climate models, various possible scenarios of nuclear war and their impacts on agriculture and the world food supply.

            As a result of international negotiations pushed by civil society led by the International Campaign to Abolish Nuclear Weapons (ICAN), and referencing our work, the United Nations passed a Treaty to Ban Nuclear Weapons on July 7, 2017.  On December 10, 2017, ICAN accepted the Nobel Peace Prize “for its work to draw attention to the catastrophic humanitarian consequences of any use of nuclear weapons and for its ground-breaking efforts to achieve a treaty-based prohibition of such weapons.”  Will humanity now pressure the United States and the other eight nuclear nations to sign this treaty?


Thursday, April 5, 2018


CIRES Auditorium, Room 338


Event Type



Refreshments provided