Expected Changes in Global Food Security and Nutrition due to Climate Change and Increased Demand for Biofuel

Climate change is steadily decreasing the reliability of food security in the 21st century. As scientists search for alternatives to fossil fuels, new research has focused on the advancement of biofuels as alternatives for petroleum. Emergent reliance on biofuel energy has spiked the prices of crops such as corn, with negative implications for people living in countries which are already suffering from hunger and high food prices. Tirado et al. (2010) discuss the several implications of food insecurity due to climate change and a growing economy for biofuel production which may result in severe malnourishment, hunger, and social unrest in the future of developing countries Bailey Hedequist
Tirado, M.C., Cohen, M.J., Aberman, N., Meerman, J., Thompson, B., 2010. Addressing the challenges of climate change and biofuel production for food and nutrition security. Food Research International 43 1729–1744.

M.C. Tirado and colleagues at the University of California, Los Angeles conducted a cumulative study of the effects of climate change on food security. Several factors play into the increasing uncertainty of crop availability due to climate change, including elevated prices for food, amplified focus on biofuel technology and production, and changes in crop yield due to climatic factors and elevated atmospheric CO2. The authors discuss the many interconnected and complex issues surrounding the effects of climate change on food security, which will be amplified in developing countries whose economies depend on agribusiness. Populations are expected to suffer from health problems such as stunting, malnourishment, water contamination from crop run-off, and social unrest due to the direct and indirect effects of climate change on global agricultural economy.
The authors used the World Food and Agriculture Organization’s (FAO’s) four-dimensional food security framework to determine the effects of climate change on food security. The framework includes the following definitions of food and nutrition security as defined by the FAO: food availability, stability of food supply, access to adequate quantities and varieties of safe, good quality food, and food safety and nutrition. The study approached food insecurity from a human rights standpoint based on international human rights principles, and including womens’ rights related to food insecurity. Terminology of food insecurity (malnutrition, undernourishment, stunting, etc.) used to describe public health was also gathered through the FAO. Poor health conditions are expected to escalate as drought, natural disasters, and temperatures become more frequent with climate change.
Ecosystem changes will significantly impact access to healthy food and water, especially in poor countries. Sea-level rise will result in frequent flooding, most likely to result in the contamination of food and water from chemical contaminants such as Persistent Organic Pollutants (POP’s) and dioxins. Global temperature rise has different effects on crops depending on region, and studies have shown that changes in atmospheric CO2 may benefit crop yield in certain areas. However, warming as high as 3°C has negative effects on crop yield in all regions, namely in dry and tropical environments. Decreased access to healthy foods due to climate change is expected to result in several different health conditions including malnourishment, stunting, low birth weight (LBW) babies, and increased infectious diseases such as HIV/AIDS. Additionally, biofuel production increases the chances of risk for health problems related to food security. Demand for ethanol and biodiesel has resulted in the spike of food prices and further decreased availability of foods used in the production of biofuels. Poor communities are expected to face greater challenges accessing crops which are used for biofuels, resulting in substitutes which are higher in starch and are more likely to be processed. Consequences include low amounts of caloric intake, subsequently effecting weight loss, nutrition, cognitive development in children, and adequate nutrient levels. An expanding market for biofuels is also projected to decrease the availability of safe drinking water due to irrigation demands during droughts and chemical run-off related to crops. 

Agricultural Water Use in China shows Correlation with Climate Change

China’s main use of water is used for agricultural production. In 2005, 64% of water use in China was dedicated to agriculture. Wu et al. (2010) researched the effects of climate change on agricultural water use in China using the Palmer Drought Severity Index (PDSI) and China’s Gross Irrigation Quota (GIQ) to find the relationship between climate change and agricultural water use in the country. The study found that advancements in irrigation technology will be necessary in order to support the growing demand for agricultural water use in China in the face of climate change. Bailey Hedequist
Wu, P., Jin, J., Zhao, X., 2010. Impact of climate change and irrigation technology advancement on agricultural water use in China. Climatic Change 100 797–805.
Pute Wu and colleagues at the National Engineering Research Centre for Water Saving Irrigation at Yangling, People’s Republic of China examined the negative effects of climate change on agricultural water use in China. The study used the Palmer Drought Severity Index (PDSI) to simulate climate change. Data for China’s total irrigated area and quantity of agricultural water used were obtained from the China Compendium of Statistics and the China Water Resources Bulletin 2006 during the period between 1949 and 2004. The Gross Irrigation Quota (GIQ) measures the quantity of agricultural water use in effective irrigation areas. The GIQ allows researchers to know how much water is used annually for irrigation in terms of water quantity per square hectometer (m3/hm2). Finally, PDSI and GIQ data are combined using a statistical regression method to find the relationship between climate change and irrigation.
The study found that during the period between 1949 and 1990, national irrigation supply showed an upward trend. Based on China’s poor advancement in irrigation technology during that period, Wu et al. concluded the increase of agricultural water availability during that period can be attributed to the downward PDSI trend during the same period. Since 1991, irrigation conservation technology has significantly improved in China, which decreases the GIQ. Using a statistical regression method, the GIQ and PDSI data are compared to determine climate change and its effects on irrigation since 1991. The data indicate that there is a significant correlation between climate and irrigation quantity. Without technological advancement to improve irrigation, climate change could have a drastic negative effect on water availability in China.
With a population of 1.3 billion, future dramatic changes in agriculture related to irrigation insufficiency could be extremely problematic for the people of China. As technology continues to advance, future intensity of water consumption could be reduced. Global warming would increase water intensity use by 100% without technological aid. China could face a major water crisis induced by climate change.
Assessment and Future Improvement of Predicting Food Security in the Midst of Climate Change
Climate change models are used by researchers to predict the effects of changes on precipitation and temperature on crop yield around the globe. However, climate change simulations have not fully developed to include other factors such as topographic impacts, natural disasters, pests, weeds, diseases, and general unpredictability of natural processes when assessing the impact of climate change on the world’s food supply. Soussana et al.(2010) evaluated several models and discussed how simulations can be improved to accurately predict future changes in global food security as atmospheric CO2 and global temperatures continue to increase. Bailey Hedequist
Soussanna, J.F, Graux, A.I., Tubiello, F.N., 2010. Improving the use of modeling for projections of climate change impacts on crops and pastures. Journal of Experimental Botany, 1–12.

Jean-Francois Soussana and colleagues at Grassland Ecosystem Research, France reviewed multiple global climate models (GCM’s) and suggested how they could be improved by including variables which will result from changes in precipitation, temperature, soil water stress, abiotic factors, and alterations in microbial interactions. While giving accurate predictions based on weather, temperature, and precipitation, GCM’s may be advanced to include other negative circumstances resulting from climate change, such as weeds and pests, which could significantly transform the globe’s agricultural market. Potential improvements are necessary in order to develop agricultural technology for countries whose main economic resource is agricultural production or those already suffering from hunger and malnourishment.
Included in the study were process-based, generic, global and regional climate change models, and downscaling methods. The authors discuss the importance of the atmosphere-ocean general circulation model (AOGCM) as being the best determiner of greenhouse gas (GHG) predictions. However, this useful type of model is limited in its accuracy regarding topography, random events, and scale resolution. The AOGCM serves as a perfect example of why models need to be improved as the same models are often re-used in different studies. Furthermore, high temperatures, drought, and elevated CO2 complicate projected climate change. Abiotic interactions with CO2 (water, temperature, nutrients, photosynthesis, and the ozone layer) vary from region to region and therefore create a more complex challenge for improving GCMs. Plant species will also have different effects from elevated CO2 exposure based on genotype, management, and environmental shifts. Pests, weeds, and diseases are also expected to increase under climate change but are nevertheless excluded in GCM’s, although their potential impact is great.
The criteria for a good climate change model are not simple, but GCMs need development in several areas in order to predict future changes in food supply with reliable accuracy. The given factors are certainly difficult to determine with complete confidence, but improved implementation of models will greatly further our understanding of the world’s food security in the next century. 

Streamflow Changes in the Nile River could have Negative Effects on Agricultural Water Use and Hydropower Production

The Nile River is the longest international river system in the world, and significantly impacts agriculture, energy, and local and regional economies. Beyene et al (2009). studied the effects of climate change on the streamflow of the Nile River using eleven General Circulation Models (GCM’s) and two IPCC climate change scenarios. The study concluded that the Nile would experience an increase in streamflow early in the century, but mid- and late century predictions expect declines. The data implicate declines in availability of agricultural water resources by the second half of the century, as well as uncertainty toward energy production at the High Aswan Dam (HAD). Bailey Hedequist
Beyene, T., Lettenmaier, D.P., Kabat, P., 2009. Hydrologic impacts of climate change on the Nile River Basin: implications of the 2007 IPCC scenarios. Climatic Change 100: 433–461. Ferrara, M.R., Trevisol, P., Acutis, M., Rana, G., Richter, G.M., Baggaley, N.. 2009. Topographic impacts on wheat yields under climate change: two contrasted case studies in Europe. Theoretical and Applied Climatology 99, 53–65.

Tazebe Beyene and colleagues at the Department of Civil and Environmental Engineering at the University of Washington conducted a study to predict how streamflow on the Nile River will be affected by climate change in the next century. The data were collected by using 11 General Circulation Models and two climate change scenarios taken from the 2007 IPCC Fourth Assessment Report. Global emissions scenarios were chosen for this study based on their popularity within climate change studies. These scenarios were the IPCC A2 and B1 scenarios; A2 represents a world with high population growth, and slow economic development while B1 represents a world which uses green technology, has slow population growth, and rapid economic growth. In the A2 scenario, global CO2 emissions are predicted to reach 850 ppm by 2100, while the B1 scenario predicts increases of CO2 levels to stabilize at 550 ppm by 2100. Results from the 11 GCM’s and the two climate scenarios were then used in the Variable Infiltration Capacity (VIC) hydrology model, a model which produces streamflow predictions when matched with climate predictions and data collected at the HAD. The VIC creates a scenario for the Lake Nasser reservoir, created by the HAD and a major source for irrigation supply. Simulating future changes at Lake Nasser creates a clearer picture of potential impacts on agriculture and hydropower production.

The results showed that, on average, it is expected that the Nile will experience increases in flow at the beginning of the century, but by mid-century river flow will decrease due to expected changes in precipitation and an increase in evaporation. Predictions for hydropower production fluctuate, increasing at the beginning of the century and declining mid-century onward under the A2 scenario. Irrigation supply is predicted to dramatically decrease in Egypt by the end of the 21st century. The study concluded that as much as 457,000 ha of irrigable land may be lost to Egypt by the end of the 21st century, and that irrigation will be more highly affected than hydropower. Population growth within Egypt suggests that loss of water supply for the region could cause a future crisis in the country. 

Temperature and Precipitation Changes and the Effects on Crop Yield in Hilled Terrain

Ferrara et al. (2009) compared the effects of climate changes using two European case studies in England and Italy to determine how climate change will affect the yield of wheat in the due to shorter growing seasons, increased drought, and altered amounts of rainfall. Two crops were used: rainfed winter wheat in Englad and rainfed durum wheat in Italy. The results of the study showed that projected effects of climate change on crop yield reflected prior speculations. Under the study’s climate change model, crop yield in both locations decreased dramatically.—Bailey Hedequist
Ferrara, M.R., Trevisol, P., Acutis, M., Rana, G., Richter, G.M., Baggaley, N.. 2009. Topographic impacts on wheat yields under climate change: two contrasted case studies in Europe. Theoretical and Applied Climatology 99, 53–65.

            R. M. Ferrara and colleagues at the Agricultural Research Council in Bari, Italy studied the effects of temperature and precipitation changes on crop yields in sloped areas. Higher temperatures will most likely result in shorter growing seasons and frequent droughts, especially in the Mediterranean. Terrain also becomes a factor, especially in hilly areas that respond dramatically to differences in the environment. Italy’s agricultural land is located largely on arid and sloped areas, and environmental changes will most likely negatively impact the crop yield in these areas.
            Two areas in Europe were studied: the Old Warden area in the UK and the Apulia region in Italy. The climates are a humid temperate climate and semi-arid climate for the UK and Italy, respectively. Using the STAMINA (Stability and Mitigation of Arable Systems in Hilly Landscapes) model, Ferrara et. al predicted the effects of climate change on agricultural yield in hilly areas using a catchment system composed of square cells which use topographic data of the given sloped areas. This model includes land features, soil quality, and meteorological data in simulating future temperature changes and its influence on agriculture. The model contains three interrelated sub-models which use micro-meteorological soil-water relationships and simulated CO2 effects on crops as factors to retrieve future crop yield estimates.

Based upon the STAMINA system, crop yield in the UK and Italy showed different results but were nonetheless both affected by climate change. Production in hilly areas in the UK showed potential increase due to precipitation changes and less chance of drought, while arid areas of Italy showed a potential decrease of –80% in sloped areas. However, results predicted that droughts are likely to become more frequent and growing seasons will shorten in the UK, having a negative effect on crop yield. The semi-arid Apulia region showed significant decreases in crop yield due to projected increases in drought and rises in temperature.  The conclusions reached from this study show the complications of obtaining robust evidence for the effects of climate change on hilly areas, but the STAMINA model also presents interesting results which will be helpful in future studies to determine effects of temperature and precipitation in sloped areas. 

The effects of climate change on rainfed crops in the Jordan basin

Al Bakri et al. conducted a study to examine the negative effects of climate change on crop yield in the Jordan Basin, using a crop simulation model to project the impact of temperature and precipitation changes on two crops, barley and wheat. Barley and wheat are both important crops for farmers in Jordan. Although both crops benefit from CO2 during their photosynthetic life cycle, the abundance of CO2 in the atmosphere no longer cancels out the harm of temperature increase and changes in precipitation related to greenhouse gasses. Under a climate change model the study found that precipitation changes in the future will negatively affect the crop yield of both wheat and barley in the Jordan basin, with barley being more negatively impacted.—Bailey Hedequist
Al-Bakri, J., Sulieman, A., Abdulla, F., Ayad, J., 2010. Potential impact of climate change on rainfed agriculture of a semi-arid basin in Jordan. Phys.Chem. Earth, 1–10.

            J. Al–Bakri and colleagues from the University of Jordan were the first to use the DSSAT climate change model to study climate change effects on crop yield in Jordan. The Yarmouk River basin, where a significant amount of rainfed wheat and barley in the country are produced, was used as the region of analysis for the study.  Irrigation is minimally practiced in this area, but rainfeeding remains as the main source of water for crops in the basin. Forty-nine percent of the land is rainfed, 7% of the land is irrigated, and the rest of the land is unfarmed. The rain season lasts from November through May, and the land presents a diverse array of soil types which is also a factor in crop production.
            The Jordan Department of Statistics (DOS) provided data on 8,000 crop yield for 8,000 holdings of 50 ha, during the years 1996–2006. The data were then matched with weather records obtained from the meteorological department of Jordan between the years of 1970–2005, with soil data from national records. The variables were then applied to a climate simulation model called DSSAT, commonly used for its simplicity and reliability. DSSAT considers country weather data, temperature, and precipitation levels as well as soil conditions, crop characteristics, and agricultural practices to determine approximate changes in crop yield due to climate change.
            Prior to running the DSSAT simulation on the data, tests were performed in order to find inconsistency in weather data and prevent error. After combining weather data with equations which calculated the effects of solar radiation on maximum and minimum temperatures, a high r2 value confirmed the reliability of the weather data. Another model was run on the varieties of wheat grown within the area, which increased the accuracy of determining climate change effects. Before a climate change simulation was run, weather and crop yield data under baseline conditions were calculated for a period of 27 years. The DSSAT model was then run, using 20 different climate scenarios to project changes in yield by the year 2050. Four temperature changes were used: +1 °C, +2 °C, +3 °C, and +4 °C. Changes in precipitation were also taken into consideration. Precipitation scenarios of 0%, +20%, –10%, and –20% were combined with temperature increase. The climate change scenarios were then matched with three different climate change models used in separate studies. The DSSAT model was then implemented using the accumulated data to conclude the effects of climate change on wheat and barley.
            Results from the DSSAT model showed an accurate projection for crop yield prior to climate change in relation to the records of actual yield, confirming accuracy. Wheat tended to be less affected by climate change, while barley showed great susceptibility to climate change. Results for both crops showed a decrease in yield as a result of negative precipitation changes. Different climate scenarios had a variation of positive and negative effects on wheat, but barley consistently decreased in yield.  

Negative effects of temperature increase on agricultural production in Sub-Saharan Africa

As global temperature continues to increase as a result of fossil fuel burning, so do the risks of hunger in Sub-Saharan Africa (SSA), an area whose population is already suffering from malnourishment and unstable economics. Climate change will affect this area intensely because much of the population relies on agriculture as its means of sustenance. Many have speculated that rises in temperature in SSA will be catastrophic to agricultural production, and this study was conducted with the purpose of determining how miniscule or great the effects will be on an already delicate food system. While speculations have been as drastic as a 50% projected decrease in agricultural yield by 2050, more exact predictions should be made in order to determine how Sub-Saharan countries will need to respond to climate change, and therefore, improve technology to support positive food production. Using a climate model which includes average country yields, average country temperatures, and projected temperature changes, this study presents convincing evidence that rising temperatures could, in fact, be detrimental to the food source of Sub-Saharan Africa. \—Bailey Hedequist
Schlenker, W., and Lobell, D.B., 2009. Robust negative impacts of climate change on African agriculture . Environmental Research Letters 5, 1–8.

W. Schlenker et. al of the Department of Economics and School of International Public Affairs at Columbia University, New York conducted a study to determine the effects of climate change in SSA on agricultural production between the years of 2046–2065. Five crops were used as variables: maize, sorghum, millet, groundnuts and cassava. Inhabitants of SSA gain vital nutrients from these five crops, and decrease in yield could be greatly damaging to people’s source of life-sustaining nourishment. Dependent variables were (i) the current country-level yields of the five staple crops per Sub-Saharan African countries (ii) the current temperature averages between the years 1961–2000 that were matched with country-level yields, retrieved from the NCC database (iii) and the projected temperature and precipitation changes for SSA that were matched with the previous variables to determine impacts of climate change on crop yield. The weather model which determined the actual current effects of temperature on crop yield was run with an additional four models: (i) average weather (ii) quadratic in average weather (iii) degree days and (iv) degree day categories which ranged from 10°C to 35°C with 5°C intervals.
            Based on the weather model, current temperature changes did not significantly affect crop yields. However, when the weather variable was changed to include predicted rises in temperature between the years of 2046–2065, the results showed negative production yield for all crops excluding cassava. Cassava served as a poor model due to the fact that it is a root crop and therefore harvested differently. The test showed that the mean negative impacts of crop yields would be as follows: –22 for maize, –17 for sorghum and millet, –18 for groundnut, and
–8% for cassava. A test was also run to determine the effects of temperature increase and precipitation. The bootstrapping method was used to repeat the test 1,000 times using 16 different models to add variability; therefore the test was run 16,000 times. Results showed that precipitation would have little to no effect on crop yield, however, temperature increase continued to show negative impacts on all crops excluding cassava. A third test was run to determine the effects based upon uncertainty of future crop yield and temperature change. Still, the results were similar to the previous tests which showed a drastic negative change in crop yield.
            Determining the exact effects of climate change on crop yield is difficult because we cannot accurately predict changes in technology, fertilizer use, and developmental use of genetically modified foods which could greatly improve the potential for positive crop yield. However, this study shows us that measures will have to be taken in order for agricultural yield to be in a positive percentile over the coming years as global temperatures continue to rise. Without the help of outside factors, Sub-Saharan African agricultural production could drastically decrease, affecting all those reliant upon it. 

Climate change may improve crop yield in Eastern Washington

             Climate change increases the likelihood for drought, disease, and pests to affect agriculture. Stöckle et al. studied the effects of climate change on agricultural production in Eastern Washington, an area which produces 11% of the country’s economy and ranks first in production of 11 commodities in the United States (Stöckle et al., 2009). Three staple crops were used in the study based on their importance to Washington’s economy; apples, potatoes, and wheat. While carbon dioxide emissions were found to in some ways assist the photosynthetic process of these crops, other factors based on climate change such as shortened rain seasons, drought, and prolonged periods of pests and disease will have negative effects on crop yield. The study concluded that in the short term, climate change will not drastically effect crop yield. However, by the end of the century yield loss is predicted to reach 25% for some crops. –Bailey Hedequist
Stöckle, Claudio O., Nelson, R.L., Higgins, S., Brunner, J., Grove, G. Boydston, R., Whiting, M., Kruger, C., 2009. Assessment of climate change impact on Eastern Washington agriculture. Climate Change, 102: 77-102.

Claudio O. Stöckle and colleagues at Washington State University, Pullman, WA studied the effects of increased atmospheric CO2 and projected climate change on agricultural production in Eastern Washington. A simulation model, CropSyst, was used to determine climate changes on the crops. The model assumes that water and nutrients are sufficient and weeds, pests, and diseases are all adequately controlled under this model. The simulation was run on selected crops and their specific locations of production: Winter wheat (Pullman, Saint John, Lind, and Odessa), spring wheat (Pullman and Saint John), potatoes (Othello), and apples (Sunnyside). The model assumes growth conditions are adequate, so other simulations were run to determine the effects of pests and disease on crop yield based on climate change.
Each crop responded differently to the CropSyst model. Winter wheat responded positively to climate change and atmospheric CO2 increase. Spring wheat showed a decrease in yield with increase in time with responses to climate change and atmostpheric CO2 increase. Potatoes showed significant declines with climate change, mostly due to shorter growing seasons. Apples showed a slight decrease with climate change but when CO2 was added as a factor, the crop showed significant increase by the end of the century. Other factors such as disease, pests, and weeds were considered in the study using separate models. Powdery mildews are diseases that affect specific crops in Eastern Washington, including grapes and cherries. Although these two crops were not analyzed under the CropSyst model, a separate simulation was run to determine the effects of powdery mildews on grapes and cherries under climate change. The results showed that powdery mildews would not greatly increase under climate change, and that they would be easy to maintain with precipitation changes. Another model was created to determine the impacts of the codling moth (cydia pomonella), one of the most problematic pests for apples in Washington State. The model was based on a system of degree days for the moth’s hatching season. Future winters will be warmer, therefore lengthening the time for moths to hatch and possibly increasing the damage of codling moths on crops. Few models which determine the future impact of weeds are uncommon, but the study predicted that increase in atmospheric CO2 will be beneficial to growth of C3 weeds, making them more able to compete with C4 crops. More suitable conditions for weed growth will economically impact farmers and increase the likelihood of herbicide use.
Although this study shows that climate change and greenhouse gasses may improve crop yield in the short term, long term environmental effects could be costly for farmers. As precipitation changes, so will the demand for irrigation for some crops. Additionally, pest and weed control will include using chemicals which may affect the health of farmers, farming communities, and consumers. Technology will eventually have to compensate for negative climate change effects. Eventually with the help of technological advances, higher atmospheric CO2 levels could enhance crop yield.