Nuclear Winter Responses to Nuclear War Between the United States and Russia in the Whole Atmosphere Community Climate Model Version 4 and the Goddard Institute for Space Studies ModelE

Abstract

Current nuclear arsenals used in a war between the United States and Russia could inject 150 Tg of soot from fires ignited by nuclear explosions into the upper troposphere and lower stratosphere. We simulate the climate response using the Community Earth System Model-Whole Atmosphere Community Climate Model version 4 (WACCM4), run at 2°horizontal resolution with 66 layers from the surface to 140 km, with full stratospheric chemistry and with aerosols from the Community Aerosol and Radiation Model for Atmospheres allowing for particle growth. We compare the results to an older simulation conducted in 2007 with the Goddard Institute for Space Studies ModelE run at 4°× 5°horizontal resolution with 23 levels up to 80 km and constant specified aerosol properties and ozone. These are the only two comprehensive climate model simulations of this scenario. Despite having different features and capabilities, both models produce similar results. Nuclear winter, with below freezing temperatures over much of the Northern Hemisphere during summer, occurs because of a reduction of surface solar radiation due to smoke lofted into the stratosphere. WACCM4's more sophisticated aerosol representation removes smoke more quickly, but the magnitude of the climate response is not reduced. In fact, the higher-resolution WACCM4 simulates larger temperature and precipitation reductions than ModelE in the first few years following a 150-Tg soot injection. A strengthening of the northern polar vortex occurs during winter in both simulations in the first year, contributing to above normal, but still below freezing, temperatures in the Arctic and northern Eurasia.

Potential of microbial protein from hydrogen for preventing mass starvation in catastrophic scenarios

“…They are selected as a limiting case scenario to assess the feasibility of potential solutions to food shocks because a solution that works in such extreme circumstances could potentially be useful in shocks of any scale. This type of catastrophe could cause below freezing temperatures over much of the Northern Hemisphere during summer ( Coupe et al., 2019 ). There are a number of catastrophes that could obscure the sun, including full-scale nuclear war causing a nuclear winter from soot rising from the burning of cities.…”

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“…The season and geographic location of soot emissions could influence soot production, rainout, and lofting, yet a systematic evaluation is lacking (6,15). The size of the conflict, fuel load, smoke composition, and plume rise introduce additional uncertainties (6,8,15,17,31,47,48). Recently revised estimates of combustible material with today's larger nuclear arsenals render previous assumptions of 5 Tg soot conservative and suggest that soot production may range from 5 to 36 Tg for the India-Pakistan case (13).…”

The Potential Impact of Nuclear Conflict on Ocean Acidification

“…Nuclear warfare could have devastating impacts on millions of people, yet it has been suggested that regional or global nuclear conflict may be possible in the future (Toon et al, ). In addition to the calamitous impacts of nuclear conflict on a local level, research conducted with a range of climate models finds a global cooling in response to various conflict scenarios (Coupe et al, ; Malone et al, ; Mills et al, ; Pausata et al, ; Robock et al, ; Turco et al, ). This global cooling is driven by fires started by the nuclear weapons.…”