If cheeseburgers is what you love to gorge on, then you're probably not an eco-friendly person, as they are among the most climate-unfriendly foods imaginable, as is determined in an article in New Scientist.

At a recent meeting of the American Association for the Advancement of Science (AAAS) that Aldhous attended, Helene York of the Bon Appetit Management Company described her efforts to bring low-carbon menus to its network of some 400 cafes on college campuses and in corporations across 29 US states.

But York admits that the cheese target will be missed, because chefs have struggled to find acceptable alternatives. "It will take more time to educate the palates of our customers," she said.

The complexity of calculating total greenhouse gas emissions for foods was revealed by other speakers at the meeting as well.

Even for the same end product, total emissions can vary widely depending on how the food was farmed or caught, transported and processed.

For proving his point, Aldhous take the help of an example."For instance, if I order salmon at a Chicago restaurant this vening, I'll do nearly five times more damage to the climate if it was farmed in Chile and flown in fresh, compared to fish rozen at sea by a seine-net vessel from Alaska," he said.