Unexpected land-surface warming following a relatively limited-forcing hypothetical nuclear war
- 1University of Toronto (Toronto, Canada)
Abstract
Nuclear conflicts could ignite intense fires that inject considerable amounts of black carbon (BC) into the upper troposphere and lower stratosphere, with the potential to disrupt global climate. While uncertainties in the BC injection remain large, relatively few modeling studies have explored the climatic response to more limited nuclear exchange between major nuclear powers. Here, we investigate the climate response to a set of relatively limited-forcing scenarios (12 to 24 Tg BC) for nuclear exchanges between the United States and Russia. This corresponds to one-tenth to one-fifth of the forcing strength of typically considered. We use the Canadian Earth System Model version 5, an independent contributor to the worldwide set of Earth System Models that has not been explored previously in this application. Consistent with previous work, decreased downwelling shortwave radiation at the surface drives prolonged surface cooling. Unexpectedly, however, a transient surface warming develops in the first boreal summer following a boreal-winter injection, linked to reduced cooling via net longwave and turbulent fluxes. The transient warming is most pronounced for the lowest forcing cases. Precipitation, which decreases even while the surface warms, is found to be controlled by stabilizing, top-heavy warming. Multi-model assessment of these relatively limited-forcing cases is warranted given their potential impacts.
Versions
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BibTeX
@article{cheung2026unexpected,
title = {{Unexpected land-surface warming following a relatively limited-forcing hypothetical nuclear war}},
author = {Anson Ka Hei Cheung and Paul J. Kushner and Francesco S. R. Pausata and Zhihong Zhuo and Marguerite L. Brown},
journal = {Earth System Dynamics},
year = {2026},
month = oct,
doi = {10.5194/esd-17-1573-2026},
url = {https://esd.copernicus.org/articles/17/1573/2026/},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Unexpected land-surface warming following a relatively limited-forcing hypothetical nuclear war
AU - Anson Ka Hei Cheung
AU - Paul J. Kushner
AU - Francesco S. R. Pausata
AU - Zhihong Zhuo
AU - Marguerite L. Brown
PY - 2026
DA - 2026/10/23
JO - Earth System Dynamics
DO - 10.5194/esd-17-1573-2026
UR - https://esd.copernicus.org/articles/17/1573/2026/
AB - Nuclear conflicts could ignite intense fires that inject considerable amounts of black carbon (BC) into the upper troposphere and lower stratosphere, with the potential to disrupt global climate. While uncertainties in the BC injection remain large, relatively few modeling studies have explored the climatic response to more limited nuclear exchange between major nuclear powers. Here, we investigate the climate response to a set of relatively limited-forcing scenarios (12 to 24 Tg BC) for nuclear exchanges between the United States and Russia. This corresponds to one-tenth to one-fifth of the forcing strength of typically considered. We use the Canadian Earth System Model version 5, an independent contributor to the worldwide set of Earth System Models that has not been explored previously in this application. Consistent with previous work, decreased downwelling shortwave radiation at the surface drives prolonged surface cooling. Unexpectedly, however, a transient surface warming develops in the first boreal summer following a boreal-winter injection, linked to reduced cooling via net longwave and turbulent fluxes. The transient warming is most pronounced for the lowest forcing cases. Precipitation, which decreases even while the surface warms, is found to be controlled by stabilizing, top-heavy warming. Multi-model assessment of these relatively limited-forcing cases is warranted given their potential impacts.
SN - 2190-4987
SN - 2190-4979
ER -