U.S. Environmental Protection Agency
EPA Science Advisory Board
Background Information

Document NameReactive nitrogen and the world: two hundred years of change
Document AuthorGalloway, J.N.
Cowling, E.B.
Short DescriptionAmbio, 31, 64-71.
CategorySubgroup 3: Scientific Basis for Goals and Management Options
Publication Year2002

Abstract: This paper examines the impact of food and energy production on the global N cycle by contrasting N flows in the late-19(th) century with those of the late-20(th) century. We have a good understanding of the amounts of reactive N created by humans, and the primary points of loss to the environment. However, we have a poor understanding of nitrogen's rate of accumulation in environmental reservoirs, which is problematic because of the cascading effects of accumulated N in the environment. The substantial regional variability in reactive nitrogen creation, its degree of distribution, and the likelihood of increased rates of reactive-N formation (especially in Asia) in the future creates a situation that calls for the development of a Total Reactive Nitrogen Approach that will optimize food and energy production and protect environmental systems.