Rule 6: Beef is by far the most environmentally costly food most people can put on their plate, which is why choosing it over alternatives is such a telling signal. Per gram of protein, beef produces many times the greenhouse gas emissions of chicken, eggs, or legumes, mostly from cattle methane and from the forest cleared for pasture and feed. It also demands far more land and water than almost any other common food. These facts are widely published and easy to find, and cheaper, lower-impact options are available in nearly every grocery store. So when someone keeps choosing beef anyway, they are showing that the environmental cost isn’t a factor in their decision. Nobody has to be perfect, but picking the highest-impact option when better ones are easy to reach is a pretty clear statement of priorities.