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Biofuels & climate change — Challenges to world food security in the 21st century
New IIASA research shows that biofuels produced from food crops may have a greater impact on food security up to 2050 than climate change. While the impacts of climate change on the global food harvest are modest at first, global warming becomes a high risk by the middle of the century and beyond, as it starts to seriously harm arable land and water resources. However, at the same time, advances in technology will mean that biofuels can be grown on non-arable land, reducing competition with food production.

By 2050 the world will need to feed about 50 percent more people than in 2000. At the same time the world population will, on the whole, be wealthier and therefore demand—and be able to afford—more agricultural products, particularly more meat. The key to ensuring sufficient food in 2050 is to deliver a 70 percent increase in food production by sustainably intensifying agriculture through yield increases and multiple uses of the land. Increased investment and research to sustain such productivity growth is clearly essential. However, until recently it has not been clear what impact climate change might have on food production in the coming decades and whether climate change impacts would place an unbearable burden on food production or be relatively benign.

Global warming has the potential to boost food production in some parts of the world (e.g., Canada, Russia) and limit it in others (e.g., southern Africa). To understand how climate change can alter food production also requires an understanding of how the changing agriculture sector affects socioeconomic conditions, from food prices to consumption patterns, and how these in turn affect food production. Thorough systems analysis that examines all potential factors can provide such an understanding.

With this in mind, the United Nations Food and Agriculture Organization (FAO) turned to IIASA’s Land Use Change and Agriculture Program to investigate the extent to which climate change and the expansion of biofuel production might alter the long-term outlook for food, agriculture, and resource availability. The findings have been used to inform international discussions at the highest level, culminating in the World Food Summit at FAO, held in Rome, Italy, 16–19 November 2009.

Impact of climate change

At the global level, the research showed that the overall impact of climate change on food production would be relatively small in the period up to 2050, provided that the carbon dioxide (CO2) “fertilization effect” materializes in farmers’ fields—a beneficial effect expected to occur as concentrations of CO2 in the atmosphere increase. For example, IIASA’s work shows that if the CO2 fertilization effect works and farmers are able to switch crops and select the most suitable for local climatic conditions, then the global production potential of rain-fed cereals on current cultivated land will actually increase somewhat, by about 3 percent by 2050. Without the fertilization effect and crop adaptation, the production potential is estimated to fall by 5 percent (lower chart, page 19).

However, this relatively benign picture on the global scale masks dramatic changes to the production potential of some world regions and food crops. For example, by using climate change spatial patterns of the UK Hadley Centre’s general circulation model, the research shows that southern Africa will lose production of rain-fed wheat, rain-fed maize, and rain-fed cereals by 44, 43, and 28 percent, respectively, by 2050. Central America, North Africa, and West Africa will also be hit hard by losses of cereal production. The world’s production potential of wheat is likely to fall by some 5 percent by 2050; in some regions, such as sub-Saharan Africa and Central America, the production potential of wheat—a preferred ingredient in hundreds of food items from bread to beer to pizza—may fall by over 50 percent. In contrast, other crops such as maize or sorghum are likely to do well from climate change, which suggests not only that farmers must adapt their crops to climate change, but that people may have to adapt their diets as well.

The broadly balanced global picture of climate change impacts on food production until 2050 assumes agronomic adaptation by farmers and does not account for changed climate variability, which is expected to increase over the coming decades and may be an important destabilizing factor in the short-to-medium term. It also hides a far more worrying outlook beyond 2050. After mid-century, negative impacts of warming dominate, damaging the productive capacity of arable land, affecting water and biodiversity resources, and causing a rapid decrease in the crop production potential in most regions and in the global aggregate. The research estimates that cereal prices will increase by 20–40 percent by 2080, cereal production will fall by 4–7 percent in the developing world, and the number of people at risk of hunger will likely increase considerably, solely because of climate change.

Impact of biofuel production

CLIMATE CHANGE AND REGIONAL FOOD PRODUCTION Results of climate change impacts on rain-fed cereal production are shown for two general circulation models (Hadley Centre and CSIRO). Each bar depicts a range of outcomes from a low-impact scenario (full agronomic adaptation, including CO2 fertilization) to a high-impact scenario (limited agronomic adaptation, excluding CO2 fertilization). Until 2050 the impact of climate change on global cereal production is relatively small, especially if farmers are able to adapt cropping patterns to the changing climate and benefit from CO2 fertilization (lower chart). However, this benign picture hides major regional differences, with some regions losing considerable cereal production and others making large gains (upper chart). After 2050 the negative impacts of global warming on food production dominate.

In the nearer future, especially until 2030, the expansion of biofuel production poses a more serious challenge for the world food system. The impact will be particularly strong if the expansion continues to rely mainly on agricultural crops and reaches the levels and follows the rapid pace implied by the mandates and targets set in many countries.

First-generation biofuels—in other words, fuels produced from conventional agricultural crops (maize, sugar cane, cassava, oilseeds, palm oil, etc.)—accounted for approximately 80–85 million tons of cereals (4 percent of global cereal production) and 10 million tons of vegetable oil (7.5 percent of global vegetable oil production) in 2008. It may be appealing to justify biofuel targets in terms of enhancing fuel energy security and contributing to climate change mitigation and rural agricultural development; however, the reality is much more complex. Setting domestic biofuel targets at the national level has local, national, regional, and global impacts across interlinked social, environmental, and economic domains.

IIASA’s simulations show that meeting ambitious biofuel targets with the production of first-generation biofuels may lead to substantially higher food prices: it reduces food consumption in developing countries, resulting in an increased number of people at risk of hunger—an estimated extra 40–130 million by 2020.

Second-generation biofuels, produced from woody or herbaceous non-food plant materials, have attracted great attention. However, the wide deployment of commercial plants of second-generation biofuels is unlikely to begin before 2020 because of the need to overcome substantial technological, logistical, and economic barriers. But once achieved, the research suggests that, even for ambitious biofuel targets requiring some 100 million hectares by 2050, land is available without having to compete with cultivated land or land needed for livestock grazing. Land for second-generation biofuel production is mainly available in sub-Saharan Africa and Latin America, as well as North America, Eastern Europe, Russia, and Central Asia.

Further information

Fischer G (2009). World food and agriculture to 2030/50: How do climate change and bioenergy alter the long-term outlook for food, agriculture, and resource availability? Paper presented at the FAO Expert Meeting on How to feed the world in 2050, 24–26 June 2009, Rome, Italy.

Günther Fischer and Harrij van Veltuizen are Senior Scientists in IIASA’s Land Use Change and Agriculture Program. Mahendra Shah is Advisor to the Director.

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Last updated: 08 Jul 2010