Finally, there is the power of the example you set in the White House. If what’s needed is a change of culture in America’s thinking about food, then how America’s first household organizes its eating will set the national tone, focusing the light of public attention on the issue and communicating a simple set of values that can guide Americans toward sun-based foods and away from eating oil.

The choice of White House chef is always closely watched, and you would be wise to appoint a figure who is identified with the food movement and committed to cooking simply from fresh local ingredients. Besides feeding you and your family exceptionally well, such a chef would demonstrate how it is possible even in Washington to eat locally for much of the year, and that good food needn’t be fussy or complicated but does depend on good farming. You should make a point of the fact that every night you’re in town, you join your family for dinner in the Executive Residence  at a table. (Surely you remember the Reagans’ TV trays.) And you should also let it be known that the White House observes one meatless day a week  a step that, if all Americans followed suit, would be the equivalent, in carbon saved, of taking 20 million midsize sedans off the road for a year. Let the White House chef post daily menus on the Web, listing the farmers who supplied the food, as well as recipes.

Since enhancing the prestige of farming as an occupation is critical to developing the sun-based regional agriculture we need, the White House should appoint, in addition to a White House chef, a White House farmer. This new post would be charged with implementing what could turn out to be your most symbolically resonant step in building a new American food culture. And that is this: tear out five prime south-facing acres of the White House lawn and plant in their place an organic fruit and vegetable garden.

When Eleanor Roosevelt did something similar in 1943, she helped start a Victory Garden movement that ended up making a substantial contribution to feeding the nation in wartime. (Less well known is the fact that Roosevelt planted this garden over the objections of the U.S.D.A., which feared home gardening would hurt the American food industry.) By the end of the war, more than 20 million home gardens were supplying 40 percent of the produce consumed in America. The president should throw his support behind a new Victory Garden movement, this one seeking “victory” over three critical challenges we face today: high food prices, poor diets and a sedentary population. Eating from this, the shortest food chain of all, offers anyone with a patch of land a way to reduce their fossil-fuel consumption and help fight climate change. (We should offer grants to cities to build allotment gardens for people without access to land.) Just as important, Victory Gardens offer a way to enlist Americans, in body as well as mind, in the work of feeding themselves and changing the food system  something more ennobling, surely, than merely asking them to shop a little differently.

I don’t need to tell you that ripping out even a section of the White House lawn will be controversial: Americans love their lawns, and the South Lawn is one of the most beautiful in the country. But imagine all the energy, water and petrochemicals it takes to make it that way. (Even for the purposes of this memo, the White House would not disclose its lawn-care regimen.) Yet as deeply as Americans feel about their lawns, the agrarian ideal runs deeper still, and making this particular plot of American land productive, especially if the First Family gets out there and pulls weeds now and again, will provide an image even more stirring than that of a pretty lawn: the image of stewardship of the land, of self-reliance and of making the most of local sunlight to feed one’s family and community. The fact that surplus produce from the South Lawn Victory Garden (and there will be literally tons of it) will be offered to regional food banks will make its own eloquent statement.

You’re probably thinking that growing and eating organic food in the White House carries a certain political risk. It is true you might want to plant iceberg lettuce rather than arugula, at least to start. (Or simply call arugula by its proper American name, as generations of Midwesterners have done: “rocket.”) But it should not be difficult to deflect the charge of elitism sometimes leveled at the sustainable-food movement. Reforming the food system is not inherently a right-or-left issue: for every Whole Foods shopper with roots in the counterculture you can find a family of evangelicals intent on taking control of its family dinner and diet back from the fast-food industry  the culinary equivalent of home schooling. You should support hunting as a particularly sustainable way to eat meat  meat grown without any fossil fuels whatsoever. There is also a strong libertarian component to the sun-food agenda, which seeks to free small producers from the burden of government regulation in order to stoke rural innovation. And what is a higher “family value,” after all, than making time to sit down every night to a shared meal?

Our agenda puts the interests of America’s farmers, families and communities ahead of the fast-food industry’s. For that industry and its apologists to imply that it is somehow more “populist” or egalitarian to hand our food dollars to Burger King or General Mills than to support a struggling local farmer is absurd. Yes, sun food costs more, but the reasons why it does only undercut the charge of elitism: cheap food is only cheap because of government handouts and regulatory indulgence (both of which we will end), not to mention the exploitation of workers, animals and the environment on which its putative “economies” depend. Cheap food is food dishonestly priced  it is in fact unconscionably expensive.

Your sun-food agenda promises to win support across the aisle. It builds on America’s agrarian past, but turns it toward a more sustainable, sophisticated future. It honors the work of American farmers and enlists them in three of the 21st century’s most urgent errands: to move into the post-oil era, to improve the health of the American people and to mitigate climate change. Indeed, it enlists all of us in this great cause by turning food consumers into part-time producers, reconnecting the American people with the American land and demonstrating that we need not choose between the welfare of our families and the health of the environment  that eating less oil and more sunlight will redound to the benefit of both.