Tired of hearing about your carbon footprint? Well, you might be hearing more about nitrogen footprints, as the EPA’s Science Advisory Board offers analysis and recommendations in a report titled “Reactive Nitrogen in the United States: An Analysis of Inputs, Flows, Consequences, and Management Options.”

The report focuses on “reactive nitrogen,”(Nr) which the authors define as biologically active, chemically reactive, and radiatively active nitrogen compounds in the atmosphere and biosphere of the earth, in contrast to non-reactive gaseous N2, which makes up about 78 percent of the air we breathe.