How to Fight Global Warming at Dinner

Substituting chicken, fish or vegetables for red meat can help combat climate change, a new study suggests.

In fact, putting these foods on the dinner table does more to reduce carbon emissions than eating locally grown food, researchers report in the May 15 issue of the journal Environmental Science & Technology.

Environmental advocates and retailers urge customers to purchase goods from local sources to minimize environmental impacts. The idea is that food grown locally requires less fuel for shipping to the store. The new study does not argue that point. Yet few studies have compared greenhouse gas emissions from food production to those of transportation. 

The production phase is responsible for 83 percent of the average U.S. household's greenhouse-gas burden with regard to food, while transportation accounts for only 11 percent, the new study found. The production of red meat, the researchers conclude, is almost 150 percent more greenhouse-gas-intensive than chicken or fish.

The study, by Christopher L. Weber and H. Scott Matthews of at Carnegie Mellon University, was funded by the Environmental Protection Agency and the National Science Foundation.

"We suggest that dietary shift can be a more effective means of lowering an average household's food-related climate footprint than 'buying local,'" the researchers write. “Shifting less than one day per week's worth of calories from red meat and dairy products to chicken, fish, eggs, or a vegetable-based diet achieves more greenhouse-gas reduction than buying all locally sourced food."

Weber and Matthews acknowledge that consumers choose food based on many other criteria, including taste, freshness and a desire to support local farming.

• Top 10 Craziest Environmental Ideas
• Quiz: What's Your Environmental Footprint?
• 10 Ways to Green Your Home