Those links seem to address the question 'does a vegetarian diet reduce carbon emissions?' which is not quite the question I was asking. The relevant question is 'what is the most cost effective way for me to reduce my carbon emissions?'. A 'yes' answer to question 1 does not necessarily imply an 'eat a vegetarian diet' answer to question 2.
As an alternative example of the same kind of distinction, a 'yes' answer to the question 'does a Prius have lower emissions than my current car?' does not necessarily imply that the answer to the question 'what is the most cost effective way for me to reduce my carbon emissions?' is 'buy a Prius'.
I agree, of course, that we must take costs into accounts. Comments by meh basically explain how to think about that.
You said, in what I consider an unjustified mocking tone, that my dietary choice was "not particularly" effective in reducing my carbon footprint. This is wrong.
For the record, I never claimed, implied, or believed, it was the most efficient thing for every single person concerned about global warming to do. I believe my writing is very clear. I feel you are being an uncharitable discussion partner. At this rate, I will not continue discussing the issue with you.
I have noticed that among philosophers, vegetarianism of one form or another is quite common. In fact, I became a vegetarian (technically a pescetarian) myself partly out of respect for an undergraduate philosophy professor. I am interested in finding out if there is a similar disproportion in the Less Wrong community.
I didn't request that this go into Yvain's survey because I want more information than just what animal products you do or don't eat; I'd also like to see nuances of the reasons behind your diet. There are a lot more shades than carnivore/vegetarian/vegan - if you want to be a vegetarian but are allergic to soy and gluten, that's a compelling reason to diversify protein sources, for instance. I'd also like to hear about if you avoid any plant foods (if you think they're farmed in a way that's environmentally destructive or that hurts people or if you have warm fuzzy feelings for plants, maybe). Here are some questions that come to mind: