"Left's war on meat"??

I guess I'm on the left (at least relative to many people I interact with), and I'm a heavy carnivore. I hate vegetables, and regard them as medicine/pills I need to take even if I don't like it. Vegetarians and vegans are not a significant political force (left or right).

As for the methane associated with meat, it is relatively trivial. "Agricultural" accounts for about 40% of methane, but that includes cultivation (especially rice). You identified a much more dangerous source (melting tundra). Also, I read an article a year or so ago regarding significant methane leaks in production facilities. As I recall, they did some imaging on a facility in L.A. that was leaking like a sieve. And then there are "burps" from the ocean resulting from methane clathrates (among other things).

Meat production can result in a lot of pollution, especially with lax enforcement. Humans produce more methane than ungulates. Not per capita, but the entire population. And our other activities (including decomposition of various wastes from humans and civilization).

Ironically, I produce more methane if I eat vegetables than if I eat meat. :-)