Study looks at climate change and farming

PITTSBURGH, April 24 (UPI) -- U.S. scientists studying how climate change affects food production say it is dietary choice that determines a household's food-related climate impacts.

Despite the popular attention paid to the distance food travels from farm to plate -- known as "food miles" -- Carnegie Mellon researcher Christopher Weber and Assistant Professor H. Scott Matthews determined food miles result in only about 11 percent of an average U.S. household's food-related greenhouse gas emissions.

They said fruit, vegetables, meat and milk produced closer to home involve fewer petroleum-based transport miles than foods trucked across country. Yet despite the large distances involved -- up to approximately 5,000 miles for U.S. food transportation -- large non-energy based greenhouse gas emissions associated with producing food make food production matter much more than distance traveled.

Weber and Matthews suggest eating less red meat and dairy products might be a more effective way to lower food-related climate impact. They said shifting to an entirely local diet would reduce the equivalent greenhouse gas emissions as driving 1,000 miles. Shifting entirely to a vegetable diet would reduce the same emissions as 8,000 miles driven per year.

The study is to appear in the journal Environmental Science & Technology.