Institute For The Future

Meat vs. Miles

Carnegie Mellon University's Christopher Weber and H. Scott Matthews argue in a new report in Environmental Science and Technology that, when it comes to the environmental (especially carbon) impact of food webs, the presence of meat in the diet matters more than the distance the food has traveled.

 

It’s how food is produced, not how far it is transported, that matters most for global warming [...]. In fact, eating less red meat and dairy can be a more effective way to lower an average U.S. household’s food-related climate footprint than buying local food, says lead author Christopher Weber of Carnegie Mellon University.

Weber and colleague Scott Matthews, also of Carnegie Mellon, conducted a life-cycle assessment of greenhouse gases emitted during all stages of growing and transporting food consumed in the U.S. They found that transportation creates only 11% of the 8.1 metric tons (t) of greenhouse gases (in CO2 equivalents) that an average U.S. household generates annually as a result of food consumption. The agricultural and industrial practices that go into growing and harvesting food are responsible for most (83%) of its greenhouse gas emissions. [...]

 

“There is more [total] greenhouse gas impact from methane and nitrous oxide than from all the CO2 in the supply chain,” Weber says. In large part, he adds, this is because N2O and CH4 emission in the production of red meat “blows away CO2?. 

 

This report will come as a surprise to exactly nobody who has listened to my yammering about cheeseburger carbon footprints, but it's still important for a few reasons:

 

• It points to a pathway for a rapid reduction in carbon impact through dietary changes;
• It underlines the complexity of the food web problem (i.e., we don't just solve it by eating locally);
• It is a good step towards developing a comprehensive lifecycle analysis of lifestyle & behavior. 

 

(Via Resilience Science)