A new study highlights the threat to food production posed by climate change. And scientists say regions that already face food security issues are among the most vulnerable.
The researchers averaged different climate change projections and calculated how farm production in regions where food supplies are marginal would be affected by higher temperatures and less rainfall. David Lobell, who led the study, said significant impacts could be felt in just a couple of decades.
LOBELL: "It's a combination of factors. One is that they have a large population of hungry people. Another is that the climate in those regions [is] particularly likely to become drier and hotter. And the other is that the crops that they rely on are particularly sensitive to drying and warming."
Lobell and his team from Stanford University's Program on Food Security and the Environment focused on 12 areas in Latin America, Asia and Africa, where many of the world's hungriest people live. They found different crops would be affected in different areas.
LOBELL: "In southern Africa we're talking about maize or corn. Wheat, also. A little bit of sorghum. In South Asia, like India, Pakistan, we're talking rice and wheat, crops like rapeseed, crops like peanuts, which are very important locally there for the hungry populations. And then in other parts of the world, cassava in central Africa or sorghum in the Sahel."
Some areas will do well, Lobell projects, at least in the medium term. Colder areas such as Canada, Russia and China might be able to expand farming as temperatures go up. But overall, and certainly over the longer term, the net impact would be less food to feed people who may barely have enough to eat today.
Experts say you don't have to project into the future to see the impact of global warming on food production. At a Congressional hearing this week, the head of the United Nations' Intergovernmental Panel on Climate Change, Dr. R.K. Pachauri, said the impact on agriculture from even modest temperature increases is already being observed.
PACHAURI: "There is evidence from my own country, India, where agricultural scientists are now finding that several crops are actually experiencing declines in yields. Wheat in particular. Wheat is very, very sensitive to temperature increases. If those temperature increases are anywhere between 1.5 to 2 degrees Celsius, they have a major impact, and we have growing evidence of that in India."
With food production threatened within a generation, Stanford's David Lobell says it's not too soon to start planning for these changes.
LOBELL: "The type of investments that are most needed for adaptation are in breeding varieties of crops that are especially tolerant of heat or drought, and improving infrastructure of rural areas, for example improving irrigation systems or installing them where they didn't exist. And also trying to diversify, perhaps, the crops that the farmers are growing from the ones that are most vulnerable to climate change to those that are least."
David Lobell and his colleagues published their paper on climate change and food security in the February 1 edition of the journal Science.