If the environmental regulations are strong enough and enforced, the beef supply will be limited and the price will go up, resulting in less consumption.

This is a difficult ask from governments obviously, but consider that the alternative is trying to convince vast numbers of people to willingly stop eating tasty meat. Humans have issues doing that when it's literally killing them and they've been told so by doctors. Expecting them to do it when told to by environmentalists seems a little less likely to me than the governmental regulation option.