The Guardian writes about the environmental impact of a variety of sources of protein, finding that peas are the least costly option environmentally speaking, while beef- particularly in deforested areas- is the most expensive variety. Note that poultry and fish are remarkably similar in costs, as we discussed a few weeks ago. Also, the article says that cattle eating natural pastures are the low end of the graph here, which is a heck of a lot better than the high end. Still, even the best beef is worse than any pork, poultry, fish, eggs, or plant sources....