Scientists discussed “Feeding a Hotter, More Crowded Planet” on NPR’s Science Friday. They focused on the interaction of climate change, the availability of water, and their effect on the availability and price of food. Some interesting points provide food for thought:
- While the “Green Revolution” of the 1960s produced higher yields, the current versions of genetically modified crops do not, in general, produce a larger harvest. They either prevent the need for pesticides or allow the use of herbicides.
- Since the Green Revolution, crop yields (bushels per acre) have been flat or even declined slightly in much of the world. There is an upper limit to what fertilizer, irrigation, and pest control can achieve. Only Africa could achieve better yields using currently available methods.
- Regions that fall into drought import grain not only because their crops may be meager, but because the grain is, in essence, a concentrated form of water. Plants use 1000 tons of water to produce one ton of wheat. It is easier and more efficient to import the wheat than the water.
- World supplies of grain are dropping, not growing, in spite of record harvests in some areas. No government is currently supporting holding land out of use.
- Climate change is producing areas of serious drought, requiring the supply of grain – and yields can’t be increased to meet the demands. Along with the cost of fuel, it is likely that food costs will increase, especially for the poorest people in the world.