Impacts of Regional Nuclear War on Food Supply

Lili Xia1, Alan Robock1, Peter Lawrence2, Danica Lombardozzi2 and Joshua Elliott3

1Department of Environmental Sciences, Rutgers University, New Brunswick, New Jersey, USA

2Climate and Global Dynamics Laboratory, National Center for Atmospheric Research, Boulder, Colorado, USA

3The University of Chicago/Argonne National Laboratory, Chicago, Illinois, USA

Climate changes due to a regional nuclear war that would impact agriculture

• Temperature Reduction

• Precipitation Pattern Change

• Total Solar Radiation Reduction

• Enhancement of Diffuse Radiation

• Enhancement of Ultraviolet Light

• Surface Ozone Concentration Change

Impact of regional nuclear war on agriculture

Country China U.S.

Crop Rice Maize Wheat Maize Soybeans

Previous work -26%1,2 -15%1 -35%1 -15%3 -10%3

1Xia, L., et al. (2015), Decadal reduction of Chinese agriculture after a regional nuclear war, Earth’s Future, 3: 37-48, doi:10.1002/2014EF000283.

2Xia, L., and A. Robock (2013), Impacts of a nuclear war in South Asia on rice production in Mainland China, Climatic Change, 116: 357-372, doi:10.1007/s10584-012-047-8.

3Özdoğan, M., et al. (2013), Impacts of a nuclear war in South Asia on soybean and maize production in the Midwest United States, Climatic Change, 116: 373-387, doi:10.1007/s10584-012-0518-1.

1,2DSSAT (Decision Support System for Agrotechnology Transfer)

3Agro-IBIS (Agro-Integrated Biosphere Simulator)

Average yield change for 5 years after a regional nuclear war:

Main Program

Weather Management Soil Plant

Soil-Plant-Atmosphere

Planting

Harvesting

Irrigation

Fertilizer

Residue

Tillage

Daily Tmax

Daily Tmin

Daily Precip.

Daily solar radiation

Water

N

P

Organic matter

Physical Properties

Maize

Wheat

Rice

Soybean

Other crops

CO2

[Xia et al., 2015]

Chinese crop production change after a regional nuclear war

[Xia et al., 2015]

Chinese crop production change after a regional nuclear war

Maize Soybean

U.S. crop yield change after a regional nuclear war

[Özdoğan et al., 2013]

Global agriculture impact from a regional nuclear war

New Model Simulations

• Model: Off-line post4.5CLM-crop

• Resolution: 2 degree

• Crops: Maize, Rice, Soybean, Cotton, Sugarcane

pSIMS – The Parallel System for Integrating Impacts Models and Sectors

• Model: pSIMS-gDSSAT

• Resolution: 0.5 degree

• Crops: Maize, Rice, Soybean, Wheat

[Elliott et al., 2014]

[Levis et al., 2012; Levis et al., 2014]

Maize yield change (%) in the second year after a regional nuclear war (CLM-crop)

Maize yield change (%) in the second year after a regional nuclear war (pSIMS)

Maize yield change (%) pSIMS CLM-crop

Maize

Rice

Global Crop Production Change

Country China U.S.

Crop Rice Maize Wheat Maize Soybean

Previous work

-26%1 -15%1 -35%1 -15%2 -10%2

CLM-crop -28% -10% -14% -26%

pSIMS -4% -1% -20% -13% 2%

Average yield change for 5 years after a regional nuclear war:

1Xia, L., et al. (2015), Decadal reduction of Chinese agriculture after a regional nuclear war, Earth’s Future, 3: 37-48, doi:10.1002/2014EF000283.

2Özdoğan, M., et al. (2013), Impacts of a nuclear war in South Asia on soybean and maize production in the Midwest United States, Climatic Change, 116: 373-387, doi:10.1007/s10584-012-0518-1.

• The spatial patterns of crop yield change due to a regional nuclear war are similar for maize and soybeans.

• Even a very small nuclear war could produce a global food emergency for a decade.

From two global crop models:

www.agmip.org/ag-grid/ggcmi