Submitted to: Issues in Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/2/2011
Publication Date: 1/18/2012
Publication URL: http://www.esa.org/science_resources/issues/FileEnglish/issuesinecology15.pdf
Citation: Davidson, E.A., David, M.B., Galloway, J.N., Goodale, C., Haeuber, R., Harrison, J., Howarth, R.W., Jaynes, D.B., Lowrance, R.R., Nolan, T., Peel, J.L., Pinder, R.W., Porter, E., Snyder, C.S., Townsend, A.R., Ward, M.H. 2012. Excess nitrogen in the U.S. environment: Trends, risks, and solutions. Issues in Ecology. Available: http://www.esa.org/science_resources/issues/FileEnglish/issuesinecology15.pdf. Interpretive Summary: Society faces profound challenges to meet demands for food, fiber, feed, and fuel while minimizing unintended environmental and human health impacts. We need to science for developing effective management policies that reduce climate change, improve water quality, and protect human and environmental health. In this paper, we describe the various sources of reactive nitrogen in the environment, illustrate their impacts to ecosystems, human health, and the climate, and offer mitigation options for reducing these impacts. This research will be of interest to lay people, scientists, and state and federal action agencies concerned about the health and environmental impacts of nitrogen pollution and its regulation.
Technical Abstract: It is not surprising that humans have profoundly altered the global nitrogen (N) cycle in an effort to feed nearly 7 billion people, because N is an essential plant and animal nutrient. Food and energy production from agriculture, combined with industrial and energy sources, have more than doubled the amount of reactive N circulating annually on land. Humanity has disrupted the N cycle even more than the carbon cycle. We present new research results showing widespread effects on coastal ecosystems, biodiversity, human health, and climate, suggesting that in spite of decades of research quantifying the negative consequences of too much available nitrogen in the biosphere, the problem is far from solved. On the other hand, there have been important successes in reducing N emissions to the atmosphere and this has improved air quality. Effective solutions for reducing N losses from agriculture have also been identified, although political and economic impediments to their adoption remain. Society faces profound challenges to meet demands for food, fiber, and fuel while minimizing unintended environmental and human health impacts. While our ability to quantify transfers of N across land, water, and air has improved since the first publication of this series, an even bigger challenge remains: using the science for effective management policies that reduce climate change, improve water quality, and protect human and environmental health.