Here is a news story that claims that: “If Everyone Ate Beans Instead of Beef … the U.S. could almost meet greenhouse-gas emission goals.”
Recently [Helen] Harwatt and a team of scientists from Oregon State University, Bard College, and Loma Linda University calculated just what would happen if every American made one dietary change: substituting beans for beef. They found that if everyone were willing and able to do that—hypothetically—the U.S. could still come close to meeting its 2020 greenhouse-gas emission goals, pledged by President Barack Obama in 2009.
Note that Loma Linda is a well-respected medical school run by Seventh Day Adventists, a vegetarian fundamentalist religion. (I have many friends who are or were raised in the SDA religion, and I very much respect them and their opinions.)
Many years ago, there was a book, “Diet for a Small Planet,” that made similar claims for the health and environmental benefits of vegetarianism.
This article does not recommend vegetarianism but simply eliminating beef.