This past fall, I traveled to Salina, Kansas, to attend the Prairie Festival, a gathering of more than 800 farmers, seed scientists, and conserva-tionists. The event was hosted by the Land Institute, which promotes sustainable models of agriculture. Of all the risks posed by global warming, one of the most universal, most troubling, and least known concerns our soil. Rising temperatures and more frequent droughts will leach moisture from the soil, rendering it less productive, which in turn will decrease and destabilize the world's food supply. Even conser-vative global warming models predict an astounding 60 percent reduction in soil moisture on U.S. farmland in this century.
The soil in this part of Kansas is fecund and rich, but the farmers I spoke with are well aware of its fragility. While they face some grave threats to their land, they also hold the key to an important solution to global warming: biofuels. The oil we use to power our cars and trucks is the second-largest source of greenhouse gases after power plants. Biofuels could slash transportation-related global warming pollution by almost 80 percent, if combined with a commitment to increased fuel economy.
Biofuels pose some environmental challenges. We have to strike the right balance between growing crops for fuel and growing crops for food. And Kansans I spoke with know firsthand how irresponsible agricultural practices bring erosion and polluted runoff to their fields and waterways. They fear that a national mobilization for ethanol or other biofuels could lead to even more harm. "Couldn't we stop global warming through energy efficiency instead?" some asked.
But there is no one solution to global warming. We have to increase our energy efficiency, improve our fuel economy, use new technolo-gies to capture carbon emissions from coal plants, produce more wind and solar energy -- and grow biofuels. And we have to do these things now, not later.
These solutions can have environmental impacts. Biofuels can damage soil, water, wildlife, and even air quality when the fuel is burned. But with the right rules and incentives, we can minimize the harm. For instance, using native perennial plants such as switchgrass as a source of biofuels can actually improve soil fertility. Biofuels policies now are blunt instruments: If you produce ethanol, the government will pay you a subsidy. We can instead provide incentives to producers who reduce soil erosion, limit fertilizer use, and protect wildlife habitat.
The biofuels industry is in its infancy; we have an opportunity now to shape its future. If we get it right, we can embrace biofuels as a smart, sustainable solution to our oil dependence and to global warming. Then farmers in the heartland can help us grow our food, produce our energy, and protect the land.