Food factors in on global warming.

• Position: Nutrition

When we think of the culprits behind global warming, usually what comes to mind are gas-guzzling vehicles and inefficient household appliances, but Eugene Cordero--professor of meteorology at San Jose (Calif.) State University and coauthor of Cool Cuisine: Taking the Bite Out of Global Warming--says there is another under-recognized source: the standard American diet. 'The latest research tells us that our diet is responsible for at least 20% of all the greenhouse gas emissions that lead to global warming," he maintains.

Cordero explains that diet is implicated in many ways, from how food is grown and processed to the amount of waste produced:

* Synthetic nitrogen fertilizers, imported food, livestock-raising practices, and overreliance on processed food are some of the main diet-related sources of climate change.

* So, just how can you measure the impact of food choices on the environment? Well, for instance, two tablespoons of the average, conventionally produced peanut butter emits 118 grams of carbon dioxide, which is equivalent to driving a hybrid vehicle about half a mile. A single conventionally produced cheeseburger emits 10.7 pounds of carbon dioxide.

* Food miles refer to the number of miles a food product has to travel to get to your plate. Food can be shipped via truck, ship, rail, or air. The most energy efficient method is ship and the least is air.

"One complication regarding food miles is that, if reducing emissions is your goal, then an understanding of how the food is produced can be as important as knowing how far it has had to travel."...