News / Health

Online Tool Shows How What You Eat Affects Pollution

Reducing animal protein consumption cuts nitrogen pollution.
Reducing animal protein consumption cuts nitrogen pollution.

Multimedia

Audio

Looking to lead a more eco-friendly lifestyle? You could start by cutting back on meat. A new nitrogen footprint calculator shows you the impact your diet has on the environment.  

You may have heard of the concept of a carbon footprint. That's how much of the greenhouse gas carbon dioxide your lifestyle generates. Now researchers have developed a way to measure how our lifestyle - and in particular our diets - impacts another major source of climate-changing pollution: nitrogen.

Everything needs nitrogen, from plants to plankton to people. It's a key element in the proteins that make up our bodies.

Good news, bad news

In the early twentieth century, scientists figured out a way to take nitrogen out of the air and turn it into a form that plants could use. The invention of synthetic nitrogen fertilizer dramatically improved food production.

"That's the good news," says environmental sciences professor Jim Galloway at the University of Virginia. "We're able to feed the world's population because of this wonderful invention."

The bad news, Galloway says, is that many parts of the world use far too much nitrogen fertilizer. Burning fossil fuels also creates nitrogen pollution. Galloway says the excess nitrogen "contributes to smog, acid rain, loss of biodiversity, dead zones along the coast, global warming, stratospheric ozone depletion. The list is quite long."

Visualizing impacts

Galloway and his colleagues developed the nitrogen footprint calculator to show how people's behaviors contribute to that long list of environmental impacts.

The calculator starts with a graph showing the amount of nitrogen pollution produced by the average person. One of the first things you notice is that food is far and away the biggest contributor: 72 percent of the 42 kilograms the average American produces comes from food consumption. Housing, transportation and goods and services make up the rest.

To see exactly how your diet affects your nitrogen footprint, the calculator lets you adjust how many times a week you eat 16 different kinds of foods.

"As you change your consumption, you can see how the graph changes," says co-creator Allison Leach at the University of Virginia. "So as you scale down one bar, you can see your nitrogen footprint shrinking."

Too much protein

Americans eat far more protein on average than the U.S. Department of Agriculture recommends, Leach says. "Reducing your protein to the recommended levels is going to have a huge impact on reducing your nitrogen footprint. [That] reduces it by almost half."

Reducing the amount of animal protein is one of the quickest ways to shrink that footprint. Galloway says that's because feeding plants to animals is an inefficient use of nitrogen.

"For large animals like beef, a very large fraction of the nitrogen that enters the cow's mouth is excreted out the back end," he says.

Beef is less efficient than chicken or pork, while plant sources like legumes are the most efficient, Leach says.

Nitrogen footprints around the world

She and her colleagues also created nitrogen footprint calculators for Germany and the Netherlands. She says their footprints are smaller largely because they tend to eat less meat, not because of major differences in their farming practices.

"Industrialized agriculture production is pretty consistent among developed countries. But it's going to be very different in developing countries."

The next step, Leach says, is a nitrogen footprint calculator for India, a developing country where farming practices are very different from in the industrialized world.

Footprints growing

But even in the developing world, nitrogen footprints are changing. The world's population is not only growing, it's also growing richer. One consequence is that people are eating more animal protein. Galloway says they have looked at what the world might look like in 2050 - and it raises concerns.

"If the entire world had the per capita resource-use habits that people in North America have, then we would be putting three to four to five times more reactive nitrogen into the environment than we are now," he says. "And that's frankly untenable. Our ecosystems can't handle that."

Galloway says that’s why it’s so important that we all do a better job managing the amount of nitrogen we put on our fields, in our mouths, and into our environment.

You May Like

Scotland Vote Raises Questions of International Law

Experts say self-determination, as defined and protected by international law, confined narrowly to independence movements in process of de-colonization More

Video Whaling Summit Votes to Uphold Ban on Japan Whale Hunt

Conservationists hail ruling as a victory, but Tokyo says it will submit revised plans for a whale hunt in 2015 More

Annual Military Exercise Takes on New Meaning for Ukraine Troops

Troops from 15 nations participating in annual event, 'Rapid Trident' in western Ukraine More

This forum has been closed.
Comments
     
There are no comments in this forum. Be first and add one

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
Russian Economy Reeling After New Western Sanctionsi
X
September 18, 2014 2:28 AM
A new wave of Western sanctions is hitting Russia’s economy hard. State-owned energy firms continue to bleed profits and Russia’s national currency plunged to a new low this week after the U.S. and the European Union announced new sanctions to punish Russia's aggressive stance in eastern Ukraine. But as Mil Arcega reports, the sanctions could also prove costly for European and American companies.
Video

Video Russian Economy Reeling After New Western Sanctions

A new wave of Western sanctions is hitting Russia’s economy hard. State-owned energy firms continue to bleed profits and Russia’s national currency plunged to a new low this week after the U.S. and the European Union announced new sanctions to punish Russia's aggressive stance in eastern Ukraine. But as Mil Arcega reports, the sanctions could also prove costly for European and American companies.
Video

Video Belgian Researchers Discover Way to Block Cancer Metastasis

Cancer remains one of the deadliest diseases, despite many new methods to combat it. Modern medicine has treatments to prevent the growth of primary tumor cells. But most cancer deaths are caused by metastasis, the stage when primary tumor cells change and move to other parts of the body. A team of Belgian scientists says it has found a way to prevent that process. Zlatica Hoke has more.
Video

Video Mogadishu's Flood of Foreign Workers Leaves Somalis Out of Work

Unemployment and conflict has forced many young Somalians out of the country in search of a better life. But a newfound stability in the once-lawless nation has created hope — and jobs — which, some say, are too often being filled by foreigners. Abdulaziz Billow reports from Mogadishu.
Video

Video A Dinosaur Fit for Land and Water

Residents and tourists in Washington D.C. can now examine a life-size replica of an unusual dinosaur that lived almost a hundred million years ago in northern Africa. Scientists say studying the behemoth named Spinosaurus helps them better understand how some prehistoric animals adapted to life on land and in water. The Spinosaurus replica is on display at the National Geographic museum. VOA’s George Putic has more.
Video

Video Iraqi Kurdistan Church Helps Christian Children Cope find shelter in churches in the Kurdish capital, Irbil

In the past six weeks, tens of thousands of Iraqi Christians have been forced to flee their homes by Islamic State militants and find shelter in churches in the Kurdish capital, Irbil. Despite U.S. airstrikes in the region, the prospect of people returning home is still very low and concerns are starting to grow over the impact this is having on the displaced youth. Sebastian Meyer reports from Irbil on how one church is coping.
Video

Video NASA Picks Boeing, SpaceX to Carry Astronauts Into Space

The U.S. space agency, NASA, has chosen Boeing and SpaceX companies to build the next generation of spacecraft that will carry U.S. astronauts to the International Space Station by the year 2017. The deal with private industry enables NASA to end its dependence on Russia to send space crews into low Earth orbit and back. Zlatica Hoke has more.
Video

Video Future of Ukrainian Former President's Estate Uncertain

More than six months after Ukraine's former President Viktor Yanukovych fled revolution to Russia, authorities have yet to gain control of his palatial estate. Protesters occupy the grounds and opened it to tourists but they are also refusing to turn it over to the state. VOA's Daniel Schearf reports from Mezhigirya, just north of Kyiv.
Video

Video China Muslims Work to Change Perceptions After Knife Attacks

China says its has sentenced three men to death and one woman to life in prison for a deadly knife attack in March that left more than 30 dead and 140 injured. Beijing says Muslim militants from China's restive western region of Xinjiang carried out the attacks. Now, more than six months after the incident, residents in the city are still coping with the aftermath. VOA's Bill Ide has more from Kunming.


Carnage and mayhem are part of daily life in northern Nigeria, the result of a terror campaign by the Islamist group Boko Haram. Fears are growing that Nigeria’s government may not know how to counter it, and may be making things worse. More

AppleAndroid