It would seem that humanity has taken two giant steps toward environmental degradation, leaving a couple of enormous chemical footprints, one encased in carbon, the other run through by reactive nitrogen. These footprints turn out to be tell-tale clues to the cause of fish kills, species extinctions, ocean dead zones, acid rain and ozone depletion, all of these predictors of diminished human life in years to come.
At the College, James N. Galloway, Associate Dean for the Sciences and Sidman P. Poole Professor of Environmental Sciences, has spent more than three decades measuring chemicals in the environment and observing their effects on flora and fauna, river and ocean, air and atmosphere. While other scientists have famously explained the influence of carbon on nature, Galloway primarily studies nitrogen and its effects on the planet’s delicate ecosystems. In its inert state, nitrogen is a vital element for all living organisms, responsible for forming DNA, enzymes, amino acids and proteins. However, humans have significantly raised the levels of environmentally damaging reactive nitrogen through our use of nitrogen-based fertilizers and our burning of fossil fuels for transportation and heating. “Reactive nitrogen is accumulating in the environment,” Galloway says. “And every year the problem gets much worse.”
A leader in international efforts to raise awareness about reactive nitrogen’s harmful effects, Galloway was the first scientist to articulate and explain the “nitrogen cascade,” a description of the element’s sequential effects. His contributions were recognized when he was honored as a co-winner of the 2008 Tyler Prize for Environmental Achievement, one of the highest awards for work in environmental science, energy and environmental health.
“Jim is a pioneer in looking at the nitrogen cycle of the Earth and how it’s changed,” says Ellis Cowling, a distinguished professor-at-large at North Carolina State University and one of Galloway’s mentors. “[Creating] awareness of nitrogen pollution and its multi-faceted effects in all sorts of ecosystems is his major contribution.”
In a May 2008 article published in Science magazine, Galloway and his colleagues proposed several strategies that might decrease the human impact on the Earth’s nitrogen cycle, including greater control of nitrous oxide emissions from fossil fuel combustion; world-wide improvements in sewage treatments to convert reactive nitrogen back to inert nitrogen; and increasing plant and animal uptake of reactive nitrogen through improved agricultural practices. Additionally, Galloway and others are advocating greater equality in distribution of nitrogen-based fertilizer to regions that can’t grow enough food for their people, including Africa and Latin America.
For his entire academic career, he has been attempting to convey his specialized knowledge to colleagues, students and the general public. It’s a “constant challenge to translate what scientist know into words,” Galloway says, but he’s committed to educate people—from U.Va. students and grade-school kids at summer camp to international policy leaders—about the human impact on the Earth’s nitrogen cycle.
If the teaching has taken on a kind of urgency for Galloway, it may be because the more he understands the process of nitrogen pollution, the more he recognizes the exponential growth of the problem, along with the diminishing amount of time we have left to solve it.
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