The New Oxford American Dictionary's 2006 word of the year is ''carbon neutral.''

The term reflects growing public concern over climate change, which Americans now rank as the country's most pressing environmental problem.

Being carbon neutral means making no net contribution to climate-damaging carbon emissions. It means driving less and more slowly, choosing a fuel-efficient vehicle, turning off lights and setting thermostats lower. Remaining emissions can then be neutralized through ''carbon offsets,'' such as planting trees or investing in ''green'' technologies like solar and wind power.

These are all reasonable suggestions. But if we're serious about becoming carbon neutral, we must also change what we eat.

For the new year, consider these greenhouse gas-lowering dietary guidelines: --Eat locally. The World Watch Institute reports that in the United States, food travels 1,500-2,500 miles from plow to plate, as much as 25 percent farther than two decades ago. Some long-distance transportation of food is unavoidable (think coffee and chocolate). But merely eliminating redundancies would produce significant savings.

The United States is a net importer of beef, for example, but exports nearly 700 million pounds of it each year. How food travels is also important. According to Peter Singer, co-author of ''The Way We Eat,'' transporting food by plane uses almost double the energy per mile as by truck and 20 times more than by ship or rail.

n Eat seasonally.

Eating locally means adopting a seasonally varied diet. In upstate New York, it means feasting on hearty roots, tubers, squashes, bulbs and fruits that maintain goodness during long-term storage. It means rethinking salad -- tender greens move aside for shredded cabbages, grated carrots, celeriac and sprouted seeds. It means eschewing produce from greenhouses, which can surpass per unit energy use and greenhouse gas emissions of imported alternatives. It means relying on preserved surpluses of actual -- not artificial -- summer.

n Buy organic

Widely accepted organic farming principles and U.S. Department of Agriculture certification rules prohibit the use of nearly all synthetic pesticides, including fossil-fuel-based fertilizers, weed killers, insecticides and most fungicides used to control plant diseases. Organic farms emit one-half to two-thirds less carbon dioxide per acre than chemical-based systems.

n Avoid junk food

Highly processed foods with added sugars and fat and stripped of intrinsic fiber and nutrients threaten our health and require substantial energy to produce, process and transport. Consider soda. Each year, Americans consume more calories from soft drinks than any other single food. To supply enough high-fructose corn syrup to sweeten the 38 gallons per capita consumed, we grow 1.4 million acres of corn. It takes 200 million gallons of gasoline to manufacture and mine the fertilizer and pesticides and to power the machinery to till the land, pump irrigation water and harvest, dry and transport the crop. That's a land area nearly twice the size of Rhode Island and enough gas to drive more than 6,000 Priuses from New York City to Los Angeles and back. And for what? Empty calories and unhealthy girth.

n Eat less meat

Choose pasture-raised. If the conditions endured by most factory-farmed animals aren't enough to make us opt for pasture-raised, perhaps our new environmental concern will be. Cattle alone may be responsible for half the world's methane emissions. Fleshing out food livestock raised in confinement is an oil-dependent system: fossil fuel is needed to cultivate, fertilize, harvest and transport feed. In contrast, pasture-based production lets livestock do what they're biologically intended to do -- forage for food. In these systems, animal droppings add fertility to pastures instead of becoming noxious pollutants. By lowering the fossil energy required to feed animals, we reduce the greenhouse gas emissions per ounce of meat or milk in our diets. Now that tastes better.

To address global warming, we need to become smarter about what we do and about what we eat. If we are, we'll all be healthier, and so will our planet.