Can a Warmer Planet Feed Us?

Before too long, our most direct link to global warming will be the food on our dinner tables. The vast bounty of our neighborhood supermarkets all depends on cycles of rain and air temperatures in far-off parts of the globe. Now, across the world, those cycles are changing and the effects will be profound — for all of us.

As patterns of wind and rain shift, no one knows exactly where the water will end up or when it will arrive. But most of the big computer models predicting Earth's future climate, including those created by NASA's Goddard Institute for Space Studies, foresee declining rainfall in the tropics. Harvests in those regions will decrease too. In India and much of Africa, already struggling with food shortages, food production will drop.

Climate change will produce more extreme weather, such as hurricanes and monsoons that can destroy crops and leave people with no food at all.

Most scientists don't foresee major changes in total food production during the next decade or two, as average temperatures increase by just a few degrees. As food production falls in sub-Saharan Africa and India, food production will actually increase (temporarily) in temperate regions such as North America and Europe. As a result, the world will become increasingly dependent on a handful of major food exporters, such as the United States, Canada, Australia, Brazil and Argentina.

Forty or 50 years from now, as today's children reach middle age, things are projected to get worse. As temperatures continue to rise, along with levels of greenhouse gases in the atmosphere, most models show global food production falling. The areas most affected will be those least able to purchase food from abroad. Foremost among these is Africa. According to some estimates, tens of millions of people could go hungry unless there's a major effort to help these countries adapt.

Agricultural communities can adapt in some ways, but it won't be easy, especially in the poorest parts of the world. The soil in many parts of Africa is highly degraded from overgrazing and overharvesting. There's very little organic matter — decomposed leaves, roots and grass — left in the soil. It isn't replenished because any leftover vegetation is used for fuel. Improving the soil would help Africa prepare for climate change by increasing harvests and also helping the soil store water. Providing alternative fuels for rural households is one way to help improve soil in sub-Saharan Africa.

Anything that increases the wealth of developing nations, especially in the tropics, will help them adapt to coming food shortages.

What can we do? Decrease our own contribution to greenhouse gases, with our driving choices, our food choices, and how we heat and cool our homes. Our new book Going Green: A Wise Consumer's Guide to a Shrinking Planet offers guidelines for these three high-impact consumer categories.

Sally Kneidel

Source: "Will a Warmer World Have Enough Food?" Dan Charles. NPR. November, 2007

Keywords:: greenhouse gases global warming food shortages Africa