Whats the obsession with lettuce? There are thousands of veggies, grains and pulses that can be grown with minimal environmental impact in comparrison to meat. I suspect lettuce one of the few plants that supports the argument.
Also, comparing lettuce to bacon is comparing the least impactful meat to most impactful veg. Rather unfair, no?A beef to broccoli comparrison wouldnt support the pro-meat argument all.
I get the impression you are enjoying a wee giggle at playing devils advocate here EGB, but the fact is, meat and dairy farming is proven to be damaging to the environment and consuming less of both would help. If lettuce is as bad (or worse), then maybe we should get behind eating more spinach instead. Id support that.
As for "cowicide". In my opinion, if less animals are bred, then their cramped conditions should improve and less land needs to be ruined to look after them. A win win in my mind.