@KNOWITALL It’s not just the cow farts (which is pretty funny). It’s the efficiency of the land use. Potatoes to Beef is something like 17:1 in efficiency with respect to land use. In other words if your 1 acre plot of land could grow 100k calories on it in potatoes, it would take 17 acres of land to grow an equivalent 100k calories of beef. There’s also the significant increase in water use for beef.
Then there’s the opportunity costs of those extra 16 acres. They could be trees extracting CO2 from the atmosphere and providing habitat to wildlife, wind farms or solar panels producing electricity, or wetland buffer zones that prevent fertilizer runoff and algae blooms downriver, etc.
I do agree though that @JLeslie can go first!