Nitrogen management and the future of food: Lessons from the management ofenergy and carbon

The food system dominates anthropogenic disruption of the nitrogen cycle by generating excess fixed nitrogen. Excess fixed nitrogen, in various guises , augments the greenhouse effect, diminishes stratospheric ozone, promotes smog, contaminates drinking water, acidifies rain, eutrophies bays and estu aries, and stresses ecosystems. Yet, to date, regulatory efforts to limit t hese disruptions largely ignore the food system. There are many parallels b etween food and energy. Food is to nitrogen as energy is to carbon. Nitroge n fertilizer is analogous to fossil fuel. Organic agriculture and agricultu ral biotechnology play roles analogous to renewable energy and nuclear powe r in political discourse. Nutrition research resembles energy end-use analy sis. Meat is the electricity of food. As the agriculture and food system ev olves to contain its impacts on the nitrogen cycle, several lessons can be extracted from energy and carbon: (i) set the goal of ecosystem stabilizati on; (ii) search the entire production and consumption system (grain, livest ock, food distribution, and diet) for opportunities to improve efficiency; (iii) implement cap and-trade systems for fixed nitrogen; (iv) expand resea rch at the intersection of agriculture and ecology, and (v) focus on the fo od choices of the prosperous. There are important nitrogen-carbon links. Th e global increase in fixed nitrogen may be fertilizing the Earth, transferr ing significant amounts of carbon from the atmosphere to the biosphere, and mitigating global warming. A modern biofuels industry someday may produce biofuels from crop residues or dedicated energy crops, reducing the rate of fossil fuel use, while losses of nitrogen and other nutrients are minimize d.