Anyone who avoids (factory farmed) meat has likely spent a fair amount of time researching alternative protein sources and their environmental impact respectively. Lucky for us, the Environmental Working Group has put together a list (and handy pocket guide) of the best and worst protein sources. Here they are:
Five Worst Protein Choices for the Environment:
5.) Farmed Salmon
The carbon footprint from lamb and beef cattle comes mostly from the methane produced through digestion, manure, the crops grown to feed them and the shipping during different stages of production. With pigs, the biggest environmental impact is in their poop and processing. The electricity, feed supplement and air shipping for farmed salmon landed it on the list. Cheese landed on the list due to 'bang for your buck.' Too much environmental impact for too little of a serving for the protein benefit.
Five Best Protein Sources for the Environment:
The good protein choices are a bit more complicated. Tofu still has a big footprint because of the carbon footprint from growing soy beans and processing it into tofu, but it is one-third that of beef. Eggs are still carrying the environmental impact of poultry farms but they offer a lot of protein per serving. Milk, if it is local, is great and beans (and lentils too) are a pretty guilt-free protein source. As far as chicken is concerned, let's just say it is better than beef.
Find more detailed lists and explanations here and here. And as always, the Environmental Working Group website is an incredible resource for this kind of stuff.