Climate change will play havoc with farming, and policy makers and researchers aren’t fully aware of the significance on food supply, according to the World Bank.
Earth will warm by 2 degrees Celsius (3.6 degrees Fahrenheit) "in your lifetime," Rachel Kyte, the World Bank’s vice-president for climate change, said at a meeting of agriculture ministers in Berlin over the weekend. That will make farming untenable in some areas, she said.
Extreme weather from China’s coldest winter in at least half a century in 2010 to a July hailstorm in Reutlingen, Germany, already started to affect food prices. In the past three years, orange juice, corn, wheat, soybean meal and sugar were five of the top eight most volatile commodities, according to data compiled by Bloomberg. Natural gas was first.
"Significant damage and destruction is already happening," Kyte said. "It isn’t a benign and slightly warmer world. It will be a volatile warming of the planet, with unpredictable impact."
Adapting agriculture to withstand a world with a changed climate and depleting resources isn’t happening fast enough, according to Achim Steiner, the director general of the UN’s Environment Programme.
The world risks "cataclysmic changes" caused by extreme heat waves, rising sea levels and depleted food stocks, as average temperatures are headed for a 4 degree Celsius jump by 2100, the World Bank reported in November 2012.
"It’s all going to take political leadership," said Gordon Conway, professor of international development at Imperial Colleage London. "We need more ministers of agriculture with self confidence who will stand up and say what they need, who will speak to their president or prime minster."
Long-term climate change may have "potentially catastrophic" effects on food production in the period from 2050 to 2100, the UN’s Food & Agricuture Organization has said.
Crop failures such as in Russia in 2010 are likely to become more common as climate change causes more extreme weather with heat and drought stress, according to a study that year led by the U.K.’s University of Leeds.
"If we look globally at climate science, we see the warming of temperatures and the resulting impact, for example extreme heat zones in sub-Saharan Africa," Kyte said. "The agricultural community has still some way to go in realizing the full significance."
World hunger is expected to worsen as climate change hurts crop production and disrupts incomes, charity Oxfam wrote in September. The number of people at risk of hunger may climb by 10 percent to 20 percent by 2050, with daily per-capita calories available falling across the world, Oxfam said.
While in some areas climate change may mean moving coffee trees "a few hundred meters up the mountain, in some places we’re talking about a wholesale change of what can be grown where, and I don’t think we’ve really started to compute that," Kyte said.
Climate change will likely cause a geographical shift and a reduction in suitable growing ranges for many crops, according to the U.K.’s Royal Botanic Gardens Kew.
A simulation of spring wheat under climate-change scenarios for northeast China indicated that in the worst case, more than 35 percent of harvests may fail through 2099 compared with a baseline rate of about 13 percent, the Leeds study found.
Based on current climate-change models, wheat output in northern India and Pakistan will fall between 17 percent and 38 percent by 2020 because of heat stress to the crop, the International Maize and Wheat Improvement Center estimates. The center is working to develop heat-tolerant wheat for South Asia.
The majority of agricultural research is focused on wheat, corn and rice, all crops which have "profound problems" in a world that’s 3 or 4 degrees Celsius warmer, according to Kyte.
"We need to increase the amount of research that goes into food crops that the poor actually eat," Kyte said.
Climate change reduced wheat yields from 1980 to 2008, with world production of the grain in the period 5.5 percent lower than it would have been without any change in temperatures and rainfall, U.S. researchers wrote in a 2011 study published in the journal Science.
Heat waves and extreme rainfall in the past decade are probably linked to global warming, according to a 2012 study from the Potsdam climate institute.
The past decade included Europe’s hottest summer in at least 500 years in 2003, while 2010 brought western Russia’s hottest summer in centuries and record rain in Pakistan and Australia, according to the Potsdam study published in the journal Nature Climate Change. Japan and some U.S. states registered all-time-high rainfall in 2011, while the Yangtze River basin in China had a record drought.
Weather extremes may cause agricultural production to move away from "extreme specialization," where farmers who can no longer be certain of spring rain for a particular crop may grow four or five different ones instead, according to Hermann Lotze- Campen, a researcher at the Potsdam institute.
Tackling waste may be crucial to feeding a bigger population in a time of climate change. About a third of food is wasted, according to UNEP’s Steiner.
"Some estimates show that if you reduce food waste to zero, we can feed 2 billion people," FAO deputy Director- General Maria Helena Semedo said.
Policy makers have a task in raising public awareness about the environmental impact of waste, according to Steiner, who mentioned the amount of water needed to produce a hamburger.
"One hamburger is six baths of water simply thrown down the drain."