Once again, I greet another cabinet appointment by President-elect Obama's with respect. Iowa Governor Tom Vilsack is a strong choice to lead the Department of Agriculture. His guidance will be essential on a host of issues facing the department, from restoring the health of our forests to ensuring the economic vitality of America's farms and rural areas.

But in that long list of challenges, two priorities clearly rise to the top: solving global warming and restoring balance to what we eat and how we produce it.

America's Farmland: the Climate Connection

Global warming has been the focus of my work for the last decade, so you might think I am looking for climate connections in strange places. But the truth is agriculture and global warming are deeply entwined. This was brought home to me two years ago when I traveled to Salina, Kansas to talk to more than 800 farmers, seed scientists, and conservationists. The gathering was hosted by the Land Institute, which promotes farming practices that are gentle on the environment. The institute's 600-acre farm sits on the fertile banks of the Smoky Hill River. The soil in this region is fecund and rich, but the farmers I spoke with know it is fragile.

Of all the ecological and societal risks from global warming, one of the most universal and most troubling -- and one of the least well known -- concerns the soil. Rising temperatures and more frequent droughts will leech moisture from the soil, rendering it less productive and decreasing and destabilizing the world's food supply. For the United States, climate models predict an astounding 60 percent reduction in soil moisture for even mid-range global warming projections.

The farmers I talked to in Kansas want to curb global warming and protect their soil. Fortunately, more and more farmers also recognize that they have a role to play in climate solutions. America's farmland holds great potential for renewable energy sources like wind and sustainable biofuels -- both of which can bring added income to family farms. Under Obama's guidance, Vilsack will have the opportunity to bring the agricultural sector together with the new administration's focus on clean energy, global warming, and economic recovery.

There will be thorny issues for Vilsack to work out, things like how to manage conflicts between food and fuel production and how to protect conversation reserves from being converted to energy crops. And current ethanol policies, which cause ecological harm, will need to be revamped. But I am encouraged by Vilsack's record on renewables, and I am confident he can move America toward a biofuels policy that is sustainable and performance based. Getting the role of Midwestern agriculture right is critical to getting national global warming regulations in the coming year, and I am glad that Vilsack's state is strongly engaged in the Midwest Governors' Greenhouse Gas Accord working and steering groups.

We Are the Food We Eat

This year has brought an explosion of public awareness and in depth reports -- from Michael Pollan to the Pew Commission on Industrial Farm Animal Production -- about the ill health of our nation's food production and supply system

Farmers and consumers need a more sustainable food system.  For example, fostering greater nutrient efficiency on the farm will save on fertilizer costs, reduce global warming nitrous oxide emissions, and help protect waterways from fertilizer runoff.   

Food should sustain and nourish us, not endanger our longevity or the environment. Vilsack should use the powers of his position to address the many issues facing our food, from genetically modified crops to pesticide use. But he should also go a step farther and create a comprehensive policy that puts American on a path toward food production that sustains humans, animals, and the land at the same time.