Richard Haeuber

Nitrogen Emissions, Deposition, and Monitoring in the Western United States

Abstract Nitrogen (N) deposition in the western United States ranges from 1 to 4 kilograms (kg) per hectare (ha) per year over much of the region to as high as 30 to 90 kg per ha per year downwind of major urban and agricultural areas. Primary N emissions sources are transportation, agriculture, and industry. Emissions of N as ammonia are about 50% as great as emissions of N as nitrogen oxides. An unknown amount of N deposition to the West Coast originates from Asia. Nitrogen deposition has increased in the West because of rapid increases in urbanization, population, distance driven, and large concentrated animal feeding operations. Studies of ecological effects suggest that emissions reductions are needed to protect sensitive ecosystem components. Deposition rates are unknown for most areas in the West, although reasonable estimates are available for sites in California, the Colorado Front Range, and central Arizona. National monitoring networks provide long-term wet deposition data and, more recently, estimated dry deposition data at remote sites. However, there is little information for many areas near emissions sources.

Who needs environmental monitoring

Environmental monitoring is often criticized as being unscientific, too expensive, and wasteful. While some monitoring studies do suffer from these problems, there are also many highly successful long-term monitoring programs that have provided important scientific advances and crucial information for environmental policy. Here, we discuss the characteristics of effective monitoring programs, and contend that monitoring should be considered a fundamental component of environmental science and policy. We urge scientists who develop monitoring programs to plan in advance to ensure high data quality, accessibility, and cost-effectiveness, and we urge government agencies and other funding institutions to make greater commitments to increasing the amount and long-term stability of funding for environmental monitoring programs.

Optimizing nitrogen management in food and energy production and environmental protection: summary statement from the Second International Nitrogen Conference.

Human efforts to produce food and energy are changing the nitrogen (N) cycle of the Earth. Many of these changes are highly beneficial for humans, while others are detrimental to people and the environment. These changes transcend scientific disciplines, geographical boundaries, and political structures. They challenge the creative minds of natural and social scientists, economists, engineers, business leaders, and decision makers. The Second International Nitrogen Conference was designed to facilitate communications among all stakeholders in the “nitrogen community” of the world. The Conference participants’ goal in the years and decades ahead is to encourage every country to make optimal choices about N management in food production and consumption, energy production and use, and environmental protection. Scientific findings and recommendations for decision makers that emerged from the Conference are presented.

Critical loads as a policy tool for protecting ecosystems from the effects of air pollutants

Framing the effects of air pollutants on ecosystems in terms of a “critical load” provides a meaningful approach for research scientists to communicate policy-relevant science to air-quality policy makers and natural resource managers. A critical-loads approach has been widely used to shape air-pollutant control policy in Europe since the 1980s, yet has only rarely been applied in the US. Recently, however, interest in applying a critical-loads approach to managing sulfur and nitrogen air pollutants in the US has been growing, as evidenced by several recent conferences, a new critical-loads sub-committee within the National Atmospheric Deposition Program, and nascent efforts by several federal agencies to apply critical loads to land management. Here, we describe the critical-loads concept, including some of its limitations, and indicate how critical loads can better inform future air-pollutant control policy in the US.

Flooding: Natural and Managed Disturbances A special issue of BioScience devoted to flooding as a disturbance

Few events capture the publics attention like large, infrequent natural disturbances. Many people vividly recall the human deaths and suffering, economic losses, and environmental changes associated with the eruption of Mt. Saint Helens (1980), the large-magnitude earthquakes in Northern (1989) and Southern (1994) California, the passages of Hurricane Hugo (1989) and Hurricane Andrew (1992), and the extensive flooding of the Midwestern United States (1993). Floods are among the most common and costly large natural disturbances that affect the United States, according to data compiled by the US Federal Emergency Management Agency: Approximately 9 of every 10 presidential disaster declarations are associated with flooding; total flood damage costs from 1990-1997 reached nearly

MercNet: a national monitoring network to assess responses to changing mercury emissions in the United States

34 billion; and more than 200 lives were lost due to flooding from 1990-1995. This issue of BioScience is devoted to examining natural and managed floods. There are several reasons to focus on the important role of flooding as a disturbance. First, numerous major floods occurred in the 1990s, including recent flooding caused by El Nifio-powered storms that affected the West and East

Nitrogen Deposition, Critical Loads and Biodiversity

A partnership of federal and state agencies, tribes, industry, and scientists from academic research and environmental organizations is establishing a national, policy-relevant mercury monitoring network, called MercNet, to address key questions concerning changes in anthropogenic mercury emissions and deposition, associated linkages to ecosystem effects, and recovery from mercury contamination. This network would quantify mercury in the atmosphere, land, water, and biota in terrestrial, freshwater, and coastal ecosystems to provide a national scientific capability for evaluating the benefits and effectiveness of emission controls. Program development began with two workshops, convened to establish network goals, to select key indicators for monitoring, to propose a geographic network of monitoring sites, and to design a monitoring plan. MercNet relies strongly on multi-institutional partnerships to secure the capabilities and comprehensive data that are needed to develop, calibrate, and refine predictive mercury models and to guide effective management. Ongoing collaborative efforts include the: (1) development of regional multi-media databases on mercury in the Laurentian Great Lakes, northeastern United States, and eastern Canada; (2) syntheses and reporting of these data for the scientific and policy communities; and (3) evaluation of potential monitoring sites. The MercNet approach could be applied to the development of other monitoring programs, such as emerging efforts to monitor and assess global mercury emission controls.

Impact of nitrogen and climate change interactions on ambient air pollution and human health

The Fine Resolution Atmospheric Multi-pollutant Exchange model (FRAME) was applied to model the spatial distribution of air concentration and deposition of nitrogen (N) compounds between 1990 and 2005. Modelled wet deposition of N was found to decrease more slowly than the emissions reductions rate. This is attributed to a number of factors including increases in NOx emissions from international shipping and changing rates of atmospheric oxidation. The modelled deposition of NOy and NHx to the United Kingdom (UK) was estimated to fall by 52 % and 25 % between 1970 and 2020. The percentage of the UK surface area for which critical loads for sensitive ecosystems are exceeded was estimated to fall from 73–49 % for nutrient N deposition. Comparison with model simulations at 1 km and 5 km resolution demonstrated that fine scale simulations are important in order to spatially separate agricultural source regions from sink areas (nature reserves) for ammonia dry deposition.

Progress in Nitrogen Deposition Monitoring and Modelling

Nitrogen oxides (NOx) are important components of ambient and indoor air pollution and are emitted from a range of combustion sources, including on-road mobile sources, electric power generators, and non-road mobile sources. While anthropogenic sources dominate, NOx is also formed by lightning strikes and wildland fires and is also emitted by soil. Reduced nitrogen (e.g., ammonia, NH3) is also emitted by various sources, including fertilizer application and animal waste decomposition. Nitrogen oxides, ozone (O3) and fine particulate matter (PM2.5) pollution related to atmospheric emissions of nitrogen (N) and other pollutants can cause premature death and a variety of serious health effects. Climate change is expected to impact how N-related pollutants affect human health. For example, changes in temperature and precipitation patterns are projected to both lengthen the O3 season and intensify high O3 episodes in some areas. Other climate-related changes may increase the atmospheric release of N compounds through impacts on wildfire regimes, soil emissions, and biogenic emissions from terrestrial ecosystems. This paper examines the potential human health implications of climate change and N cycle interactions related to ambient air pollution.

Nitrogen Deposition, Critical Loads and Biodiversity: Introduction

The chapter reviews progress in monitoring and modelling of atmospheric nitrogen (N) deposition at regional and global scales. The Working Group expressed confidence in the inorganic N wet deposition estimates in U.S., eastern Canada, Europe and parts of East Asia. But, long-term wet or dry N deposition information in large parts of Asia, South America, parts of Africa, Australia/Oceania, and oceans and coastal areas is lacking. Presently, robust estimates are only available for inorganic N as existing monitoring generally does not measure the complete suite of N species, impeding the closing of the atmospheric N budget. The most important species not routinely measured are nitrogen dioxide (NO2), ammonia (NH3), organic N and nitric acid (HNO3). Uncertainty is much higher in dry deposition than in wet deposition estimates. Inferential modelling (combining air concentrations with exchange rates) and direct flux measurements are good tools to estimate dry deposition; however, they are not widely applied. There is a lack of appropriate parameterizations for different land uses and compounds for input into inferential models. There is also a lack of direct dry deposition flux measurements to test inferential models and atmospheric model estimates.