Beef: Meat Industry's Worst Eco-Offender

Think drive-thru cheeseburgers are cheap? Think again. What may be light on the wallet is heavy on the planet, according to a new study on the environmental costs per calorie of beef, pork, poultry, dairy, and eggs—which, combined, make up 96% of the calories Americans get via animal sources. But, as LiveScience reports, the worst offender is beef: Not only does it require about 10 times the resources as pork and poultry (including 28 times the land), but when compared to calories gotten from plants, beef uses 160 times more land, 19 times more fertilizer, 11 times more greenhouse-gas emissions, and 8 times more irrigation water.

While this isn't the first study to pinpoint the resources used to raise cattle, the authors say it is one of the largest ever conducted to investigate the full extent of environmental costs across different types of livestock in the US, thereby allowing for direct comparisons. Not ready to drop meat from your diet altogether? "Eliminating beef, and replacing it with relatively efficient animal-based alternatives such as eggs, can achieve an environmental improvement comparable to switching to plant food source," one researcher tells the BBC. Other researchers say the conclusions can likely be extended to Europe. (Check out what is predicted to happen if the whole world suddenly goes vegetarian.)