Nuclear War Investigation Related to a Limited Nuclear Battle with Emphasis on Agricultural Impacts in the United States

Abstract

A limited battle involving the nuclear arsenals of India and Pakistan would have significant climatic impacts upon agricultural crop production in the United States; corn, soybeans, and winter wheat yields would be significantly reduced in the Corn Belt region of the US. The most severe impacts would occur during the second year after the modeled nuclear battle.

Introduction

The Natural Resources Defense Council (NRDC 2002) has suggested that both India and Pakistan have nuclear weapons and have been threatening each other over the Kashmir Region and other issues. Investigations by Robock and Toon (2010) have demonstrated that even a limited nuclear battle involving the nuclear arsenals of India and Pakistan would have significant climatic impacts throughout the world. They estimated that mean global temperatures would decline an average of 1.25 °C with greater declines occurring in the interior regions of North America and Eurasia (Robock and Toon 2010). In addition, significant declines in precipitation were projected globally.

Estimates are that these climatic changes could cause significant declines in global food production and could trigger increased famines on top of the current world malnutrition problem—currently >66 % of the world population is malnourished (WHO 2000; FAO 2009). Of the >4700 million malnourished humans, 2000 million are iron malnourished (WHO 2000) and 1020  million are protein/calorie malnourished (FAO 2009). Specifically in India, 48 % children under the age of 5 are reported to be chronically malnourished (Arnold et al. 2009).

Globally, grains make up >80 % of the world food supply (Pimentel and Pimentel 2008). Although much of the world croplands are occupied by grains and other crops, malnutrition is still a growing problem globally (WHO 2000; FAO 2009). Furthermore >99.7 % of human food comes from soils of the terrestrial environment, while <0.3 % comes from the oceans and other aquatic ecosystems (FAOSTAT 2011). Worldwide, of the total of 13 000  million hectares of land area on earth the percentages according to use are: cropland 11 %, pasture land 27 %, forest land 32 %, urban development 9 %, and other 21 %. Most of the remaining “other” land area (21 %) is unsuitable for crops, pastures, and/or forests because the soil is too infertile or shallow to support plant growth or the climate and region are too harsh, cold, dry, steep, stony, or wet (FAOSTAT 2011). Most of the suitable cropland is already in use growing crops.

In 1960, when the world population numbered only 3000  million, ~0.5 ha was available per person for the production of a diverse, nutritious diet of plant and animal products (Giampietro and Pimentel 1994). It is widely agreed that 0.5 ha of cropland is essential for a healthy diet. As the human population has continued to increase, an expansion of diverse human activities has dramatically reduced cropland and pasture land. Much vital cropland and pasture land has been covered by transportation systems and urbanization. In the US, about 0.4 ha (1 acre) of land per person is covered with urban developments and highways (USBC 2009). In 1950, only 20 % of the world population was malnourished (Grigg 1993). However, today the percentage of people that are malnourished is >66 % (WHO 2000; FAO 2009). Thus, the impact of a limited nuclear war simulated in this study has great significance.

US Corn Belt

The US Corn Belt is the most important food producing area in the United States, accounting for about 70 % of US grain (Iowa, Illinois, Nebraska, Minnesota, Indiana, and Wisconsin) (USDA 2010a). This area is ideal for grain production because of the productive soils (available nutrients), favorable temperatures and rainfall (Troeh et al. 2004; Average Weather in Des Moines 2011). The soils are rich with organic matter (4–5 %), essential for high crop productivity. The growing season temperatures are also ideal for crop production. Especially vital is seasonally well-distributed rainfall that ranges from about 80 to 89 cm of precipitation as rainfall per year (Average Weather in Des Moines 2011; Neild and Newman 2011).

The two dominant crops in the Corn Belt are corn and soybeans along with some wheat. Corn and soybeans are frequently grown in rotation with one another. This rotation facilitates both the insect and the disease control. In addition, when corn is grown after soybeans, the corn crop benefits from about 40 kg/ha of nitrogen remaining after the soybean crop is harvested (O’Leary et al. 2008).

Climatic Data for the Corn Belt Region During the Simulated Nuclear Winter Study

Alan Robock, Rutgers University developed two models to project the effects on world climate as a consequence of a limited nuclear war between India and Pakistan (pers. comm.). The Corn Belt region was selected because >70 % of US grains are produced in this region of the United States (USDA 2010a). The changes modeled in the Corn Belt were developed by Robock and his staff for an area centered on 42°N, 95°W in the United States, about 2.6 km WSW of Halbur and Carroll, Iowa (Degree Confluence Project 2012).

The simulated climatic data for this investigation (Table 1) were provided by Robock. Before reporting more on how we made these climate impact assessments, we should report that Texas and the Southwestern region of the US has had little or no rain for the past year which makes planting any corn, soybeans, or winter wheat impossible. In addition, the Corn Belt is presently (May 2011) flooded and the farmers in this region will be unable to plant as usual in early May and will be lucky to plant by early June. Thus, yields of corn, soybeans, and winter wheat will be severely reduced (50 % or more). This provides a little background of how difficult it is to estimate the impacts of the limited nuclear war on the production of corn, soybeans, and winter wheat as suggested by the simulated temperature, precipitation, sunlight, and frost impacts.

Table 1.

Simulated climatic data for the US Corn Belt as a result of a limited nuclear war between India and Pakistan

Month	Temperature anomalies (°C)	Precipitation anomalies (mm/day)	Short wave anomalies (W/m2)	Frost-free anomalies (days)
Simulated year ONE
January	0.42	−0.34	0	12 More than average
February	1.81	−0.26	0
March	0.51	0.39	0
April	0	0.06	0
May	−1.97	0.44	−10.6
June	−1.58	0.64	−30.6
July	−1.50	−0.93	−24.4
August	−0.98	−1.16	−20.7
September	−1.68	−0.79	−15.2
October	−2.05	−0.70	−14.2
November	−3.16	−1.08	−15.0
December	2.46	−0.06	−13.3
Simulated year TWO
January	−0.25	−0.01	−15.0	23 Less days than average
February	0.23	−0.23	−15.6
March	−4.20	−0.57	−21.8
April	−3.65	−2.24	−20.4
May	−4.06	−0.62	−23.0
June	−2.21	−0.48	−18.0
July	−0.92	−0.81	−20.6
August	0.51	−0.50	−19.3
September	−0.57	−1.29	−15.1
October	−2.67	−0.07	−14.8
November	−3.75	−0.49	−11.2
December	−1.36	−0.40	−10.6
Simulated year THREE
January	−0.53	−0.02	−11.4	9 Less days than average
February	0.98	−0.21	−14.3
March	−0.64	−0.15	−15.0
April	−2.68	−1.03	−21.8
May	−2.15	−0.36	−16.5
June	−0.81	−0.62	−20.4
July	0.12	−0.27	−17.8
August	0.62	0.49	−16.2
September	0.40	0.69	−12.7
October	−2.86	−0.11	−13.7
November	−2.29	−1.05	−11.2
December	−0.10	−0.49	−9.6

Grid Box centered on 42°N latitude, 95°W longitude—Des Moines, Iowa, USA

Source Dr. Alan Robock, Department of Environmental Sciences, Rutgers University, Personal Communication, Jan 24, 2011

After examining all the information on temperature impacts on corn and soybeans (Iowa State University Extension 2001; Nielsen and Christmas 2002; Lobell and Asner 2003; Elmore et al. 2006; Food Inc. 2008; Kucharik and Serbin 2008; Schlenker and Roberts 2009; USDA 2010a; Climatetemp.info/usa/des-moines-iowa.html 2011), we finally settled on 0.07 impact times each °C temperature decline that corn and soybeans were exposed to. For example, a 2 °C decline in temperature resulted in a 14 % decline in corn or soybean yield. Schlenker and Roberts (2009) used the aforementioned approach for each temperature increase related to global temperature change. After examining all the literature, we concluded that this was the best approach to be used in the assessment for each 1 °C decline. Winter wheat—because of when it is planted, grows, and is harvested—did not appear to be affected by cool temperatures (USDA 2010a).

The impacts of reduced rainfall were the most difficult to deal with because of the variability in impacts on corn, soybeans, and winter wheat (see Tables 2, 3, 4). We finally decided that the best approach would to calculate the mean rainfall for the particular growing season for corn and soybeans and for winter wheat using rainfall data for Des Moines, Iowa and assumed that this would result in an expected yield of about 9000 kg/ha for corn and 3000 kg/ha for winter wheat and soybeans. Then, we examined the simulated rainfall data reported for the growing season and what the experimental impacts were for the crops in the Corn Belt. Then the yields of corn, soybeans, or winter wheat were reduced an equivalent percentage based on the percentage reduction in rainfall reported in the simulation. These crop yield data reductions based on rainfall reductions for the simulations for the three crops did not appear to be unreasonable based on the data for corn, soybeans, and winter wheat yields (Satorre and Slafer 1999; Changnon and Hollinger 2003; Lobell and Asner 2003; Wilhite 2006; Andersen 2007; Integrated Pest Management Resources 2008; Environmental Working Group 2009; Swoboda 2010; Climatetemp.info/usa/des-moines-iowa.html 2011).

Table 2.

Crop production in Corn Belt region (kg/ha) (see weather data in Table 1)

Year 2010	Temperature (Table 1)	Rainfall (Table 1)	Mean total yield
0	9000	9000	9000
1	7770	8550	8145
2	4410	530	2470
3	7605	7308	7457

Table 3.

Soybean production in Corn Belt region (kg/ha) (see weather data in Table 1)

Year 2010	Temperature (Table 1)	Rainfall (Table 1)	Mean total yield
0	3000	3000	3000
1	1950	1440	1695
2	1590	0	0
3	2534	2250	2392

Table 4.

Winter wheat in Corn Belt region (kg/ha) rainfall (see weather data in Table 1)

Year 2010	Temperature (Table 1)	Rainfall (Table 1)	Mean total yield
0	3000	3000	3000
1	3000	2880	2940
2	3000	2580	2790
3	3000	2850	2925

Crop Yield Data for the Simulated Nuclear Conflict Study

For the model year ZERO corn yields are assumed to average 9000 kg/ha (USDA 2010a) (Table 2). The model year ONE corn yield is 90.5 % of year ZERO or 8145 kg/ha. The most severe temperature and moisture reductions were projected to occur during year TWO. Thus, the total corn yield for year TWO was calculated to be reduced significantly by 72.5 % or to an average mean yield of 2470 kg/ha (Table 2). Variations in frost and solar radiation were not assumed to have an impact on corn yields for this experimental period.

Soybeans would suffer more severe impacts on yields from global climatic effects than corn (Table 3). The average soybean yield for model year ZERO with pre-war temperature and rainfall is assumed to average 3000 kg/ha (USDA 2010a). Based on the reduced mean temperature and rainfall for model year ONE, it is calculated that soybean yield might be reduced a total of 1410 kg/ha (47%) from temperature reduction (Table 3) to a mean average yield of 1695 kg/ha. For model year TWO, based on the reduced temperature and rainfall estimates the total soybean yield is calculated to be reduced by 100 %—a total loss. Variations in frost and solar radiation were not assumed to have an impact on soybean yields for any of the growing seasons during the experimental period.

Winter wheat would also suffer significant impacts from global climatic effects due to the climatic impacts of global climate change due to simulated nuclear war (Table 4) but less than either corn or soybeans. For the model year ZERO winter wheat yields were assumed to average 3000 kg/ha (USDA 2010a). Based on the reduced mean temperature and respective model years and the range of climatic conditions conducive to wheat, winter wheat yield would not be affected by temperature reductions predicted. Reduced rainfall is calculated to reduce winter wheat yields 120 kg/ha (4 %) for year ONE (Table 4). Reduced rainfall during model year TWO would be expected to reduce winter wheat yields 420 kg/ha (14 %) (Table 4). Thus, the reduction in winter wheat yield for model year TWO is significant. Variations in frost and solar radiation are not assumed to have an impact on winter wheat yields for this experimental period.

Discussion: Impacts on of a Limited Nuclear War on the US Food System

Total US corn grains produced are estimated to be about 355 million metric tons per year, plus about 90 million metric tons of soybeans produced per year (USDA 2010a). US grains are consumed directly as bread, cereals, drinks, and other products, and about 150 million tons of the grains are fed to livestock to produce milk, eggs, and meat (World Resources Institute 2007). Thus, reducing grain production in the Corn Belt by >65 % would have a major impact on the US food system and diet of individual Americans. In addition, the US exports about 55 million metric tons grain per year and any production decline will draw down the supply of grain for consumption or export (USDA 2010a). One approach to conserve our grain might be for the US to reduce exports of grain (USDA 2010a). Such a change could increase the malnutrition problem (Pimentel and Satkiewicz 2012).

An additional 105 million tons or 30 % of corn grain is converted into ethanol (Pimentel and Patzek 2008; Weise 2011). This provides 45 000 million liters of ethanol but 1.5 l of liquid fossil fuel are required to produce each liter of ethanol (Pimentel et al. 2012). Thus, there is a net loss of 70 000 million liters of liquid fossil fuel and the nation is importing oil and natural gas to produce the ethanol (Pimentel 2012). Subsidies (paid by US taxpayers) of >$12 000 million per year are the only reason that the US is producing corn ethanol (Koplow and Steenblik 2008). Simply discontinuing the federal government subsidies would likely cause most of the corn ethanol production to cease and free up corn grain for other uses.

Note the many uses of corn leaves only 45 million metric tons available for human consumption in the United States (USDA 2010b) which is the reason that corn grain and food prices have increased by 20 % since 2005; food costs have increased about $9000 million annually (US Congressional Budget Office 2007).

Limited Nuclear War and Potential Famine

In calculating the potential climate impacts of a limited nuclear war on corn grain production, wheat production and soybean production in the US Corn Belt, the greatest climatic impact was estimated to be during year TWO because it would take some time for the climate impacts to reach the United States Corn Belt. The production of corn, wheat, and soybeans are projected to suffer approximately a 65 % reduction in crop yields during the year TWO of the modeled nuclear war (see the year ONE impacts on corn grain, soybeans, and winter wheat). Thus, instead of 445 million metric tons of grain (including soybeans) for the US grain sector, only 242.5 metric million tons of grains are potentially available. This quantity of grain (including soybeans) is totally inadequate for the population of 310 million people in the US. Some potential changes could be made in the food system to lessen this impact. These changes might include reducing livestock products like meat, milk, and eggs by one half which could be achieved by moving to a grass-fed livestock system in the US, and producing only animal products like milk and beef from livestock that can subsist on grass (Pimentel et al. 1980). This would free up about 150 million metric tons of grain, including soybeans. Also, assume that the export of 55 million metric tons of grain would totally cease. The result would be about 392.5 million metric tons of grain (including soybeans) available for the American people as food. This shift, a response to reduced grain production due to a limited nuclear war, away from grain exports would create severe grain shortages worldwide and increase world malnutrition (USBC 2009; USDA 2010a).

Summary of Nuclear War Impacts on Food Supply in the US

The potential impacts of climate changes in the United States from a limited nuclear war between India and Pakistan and the impacts on agriculture and food supply in the US have been assessed. Based on the simulated climatic data for the US Corn Belt in Table 1, specifically changes in temperature and rainfall, the sharpest decline in yield for all three crops considered is for model year TWO with a 72.5 % yield decline for corn, a 100 % yield decline for soybeans, and a 7 % decline for winter wheat. For year THREE the corn yield recovers to 7457 kg/ha, 83 % of the year ZERO yield while soybean recovers to 2392 kg/ha, 80 % of the year ZERO yield and winter wheat recovers to 2920 kg/ha, 97 % of the year ZERO yield.

Facing production declines in soybeans and corn predicted in year TWO after the modeled limited nuclear war would likely force the US to end grain exports to make up some of the grain deficit. If no grain from the Corn Belt is exported and if livestock production is changed to a grass-fed system and corn ethanol production is eliminated by discontinuing government subsidies, there would be minimally sufficient grain and soybeans for the American people. Of course, if US grains exports ceased, this might increase malnourishment in Japan, Mexico, Egypt, Yemen, Nigeria, China and some Asian countries (USBC 2009).

Biographies

David Pimentel

is a professor of ecology and agricultural sciences at Cornell University. Ph.D. from Cornell University; postdoctoral study at Oxford University. His research spans the fields of energy, biotechnology, invasive species, population, land and water conservation, and environmental policy. Pimentel has published more than 700 scientific papers and 37 books. He has served on many national and government committees including the National Academy of Sciences; President’s Science Advisory Council; US Department of Energy; US Department of Agriculture; US Department of Health, Education and Welfare; Office of Technology Assessment; and the US State Department.

Michael Burgess

is graduated with a B.S. from Rutgers—The State University of New Jersey. Attended graduate school at Cornell University for 3 years and has worked as a technical assistant for many years.