You may know your carbon footprint, but do you know your nitrogen footprint?
The researchers have taken the concept of the carbon footprint -- the measure of greenhouse gases produced by an individual's daily activities and expressed in the equivalent amount of carbon dioxide -- and have developed a similar tool for nitrogen.
While carbon dioxide is one the greenhouse gases blamed for global warming, some nitrogen compounds are nutrients that can spawn oxygen-robbing algae blooms when they reach the Chesapeake Bay. Nitrogen runoff in the Midwest is also blamed for algae blooms that have led to dead zones in the Gulf of Mexico.
"By calculating our individual impact, and taking small steps to reduce it, we can all play a part," said lead researcher Allison Leach, of the University of Virginia.
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.
The calculator asks users how many times a week they eat beef, pork, chicken, dairy and other items, as well as how many hours they spend in flight each year, how far they drive, and the size of their home, among other questions. Users are given a score in pounds or kilograms of nitrogen, as well as how it compares to the average for their country.
The researchers said they are also creating a calculator for farmers and other nitrogen users, and a tool for policymakers to show how much nitrogen can be released regionally without major negative environmental impact.
In addition to work by the researchers at the two universities, the project is supported by the U.S. Environmental Protection Agency; the Auguron Institute, a private grant-making organization for biology and chemistry projects; and the Energy Research Center of the Netherlands.