My research focuses on beneficial and detrimental effects of reactive nitrogen as it cascades through the environment.  I approach the topic from two perspectives—biogeochemical and translational.  On the former, the amount of N₂ converted to some form of reactive N increases yearly and is projected to do so in the future.  Key questions are, how much is created and what are the environmental impacts?  From the translational perspective, I and my colleagues have developed a series of nitrogen footprint tools that can be used by individuals, institutions, and communities to determine, and then manage, their contributions to N pollution.

Principal Contributions

Up to the early 2000s, my research focused on the question—how have people altered the biogeochemical cycles of N and S, and what have been the consequences?  After that, I added a new dimension—how can people lessen their contributions to N pollution?  This focus led to the development of the International Nitrogen Initiative, the N-Print and the nitrogen footprint tools.

• 1976: resolved the controversy about source of acidity in acid deposition with publication in Science.
• 1979: started the Shenandoah Watershed Acidification Study to determine the impact of acid deposition on southeastern mountain streams. In 2023, SWAS continues to address questions about impacts of acid deposition and the greenhouse effect on mountainous regions.  SWAS is the longest-running record of stream water composition and discharge in the U.S. national park system.
• 1983: established baseline for precipitation composition in remote global regions for comparison with populated regions.
• 1995: published global assessment of environmental responses to human-induced conversion of N2 to reactive forms of nitrogen.
• 2003: Founding chair of International Nitrogen Initiative (INI) whose mission is to optimize nitrogen use in food and energy production & minimize the consequent harm to humans and the environment. The INI now has regional centers in all continents except Antarctica. 
• 2003: Published the concept of the nitrogen cascade that illustrates the movement of human-produced reactive nitrogen as it cycles through various environmental reservoirs in the atmosphere, terrestrial ecosystems, and aquatic ecosystems of the Earth.  
• 2008: received the Tyler Prize for Environmental Achievement (shared with Harold Mooney) for the quantitative characterization and detailing of biogeochemical cycles, the multiple impacts of human inputs to them, and the consequences for the global environment, particularly as illustrated through the development of the concept of the nitrogen cascade.
• 2009: Using the funds from the Tyler Prize, developed the concept of the nitrogen footprint. 
• 2011: N-Print project (https://n-print.org) was launched at the 2011 AAAS meeting.  Since its beginning, members of my group have developed footprint country-specific tools for individuals, institutions, and communities.  These tools are first used to measure, and then to manage an entities’ nitrogen footprint.

Selected Key Publications (See CV for a complete listing)

Galloway Google Scholar Link

(Web of Science H-Index = 81)

• Galloway JN and EB Cowling. 2021. Reflections on 200 years of Nitrogen, 20 years later. Ambio 50, 745.
• Galloway JN. 2017. Footprints Make an Impression: an editorial. Sustainability: the Journal of Record 10, 7.
• Galloway, JN, AM Leach, JW Erisman and A Bleeker. 2017. Nitrogen: The historical progression from ignorance to knowledge, with a view to future solutions. Soil Research 55, 417
• Galloway, JN, W Winiwarter, A Leip, AM Leach, A Bleeker4 and JW Erisman. 2014, Nitrogen footprints: past, present and future. Environ. Res. Lett. 9, 115003.
• Galloway JN, AR Townsend, JW Erisman, M Bekunda, Z Cai, JR Freney, et al. 2008. Transformation of the nitrogen cycle: recent trends, questions, and potential solutions. Science 320, 889-892.
• Galloway JN, FJ Dentener, DG Capone, EW Boyer, RW Howarth et al. 2004. Nitrogen cycles: past, present, and future. Biogeochemistry 70, 153.
• Galloway JN, JD Aber, JW Erisman, SP Seitzinger, RW Howarth et al. 2003. The nitrogen cascade Bioscience 53, 341.
• Galloway JN, EB Cowling. 2002. Reactive nitrogen and the world: 200 years of change. Ambio 31, 64.