Those who've taken my class may remember talking a bit about the impacts of meat on the environment. Cutting down meat consumption even a little can have a big impact, as described in this article. They advocate the "mixed burger," a hamburger that's not 100% meat but is mostly meat mixed with mushrooms. That sounds pretty tasty as well as more eco-conscious than the pure stuff!
Update June 2019: Science magazine is chiming in, arguing that eating less meat is a great step toward decreasing our footprint: "Most strikingly, impacts of the lowest-impact animal products typically exceed those of vegetable substitutes, providing new evidence for the importance of dietary change."
