WASHINGTON (AP) -- You may know your carbon footprint, but do you know your nitrogen footprint?
Researchers at the University of Virginia and the University of Maryland have developed an online calculator to figure it out.
MORE: N-Print website
While carbon dioxide is a greenhouse gas blamed for global warming, some nitrogen compounds are so-called nutrients that can spawn oxygen-robbing algae blooms when they reach the Chesapeake Bay and other waterways.
Nitrogen pollution comes not only from excess fertilizer used on lawns and farms, but is also found in automobile and power plant exhaust. The website also has recommendations on how to reduce your nitrogen footprint, including cutting air travel, using renewable energy and eating less meat -- especially beef, because cattle require large amounts of feed.