Good discussion.
Pileus: Perhaps you missed my reference. Vast numbers of people did, in fact, suddenly make drastic and basic changes to dietary habits that go back many thousands of year...it was called the Atkins diet. It is still suppressing bread sales. So your statement that such is impossible seems to be disproved by very recent, well documented history.
When you say:
Pushing an absolutist approach or demands for purity tends to have the opposite effect. It pushes people away. Presenting evidence to people on a range of fronts (nutritional, stewardship to animals, environmental, implications to emissions and climate change, etc) and highlighting how to gradually transition to a plant based diet would likely be more successful.
I wonder who you are talking about. I have not been intending to 'push and absolutist approach' or 'demand purity.' I just applauded another poster for moving lower on the food chain, even though he is far from being a vegetarian, much less vegan. I myself, though mostly vegan, would not throw away a hamburger served to me in error, since my main reason for my veganism is avoiding waste.
And in fact, I have been exactly presenting evidence on pretty much all of the fronts you mention. And I also agree that: "If some or most people reduce animal intake by 50%, or even 20%, that should be considered progress and a win, not some sort of moral failure."
So I guess I am glad we are in agreement on those things, but perhaps you misinterpreted something I said above, or did not take the time to read much of this thread before posting on it to see what the stated positions actually were (something I am all too often guilty of myself)?
Paddy: Nice to hear that hummus is gaining popularity. There are lots of great foods that are cheap, easy to make quickly, nutritious and vegan/vegetarian. Vegan foods are, after all, the backbone of most culture's basic cuisine.
mati: Subsistence farmers, and the poor in general, produce less GHG than anyone else. No one is going out to goat herders in Sudan and trying to get them to be vegan LOL. But note that about 30 - 40% of Indians claim to be vegetarian, the highest rate in the world. Many/most of those are probably not very 'rich,' so it's not just a choice made by elites who 'can afford it.'
https://en.wikipedia.org/wiki/Vegetarianism_by_countrySince the richest 20% or so produce nearly all of the GHGs (and other pollution), it is indeed the 'rich' (=all of us) who need most rapidly to draw down our emissions as quickly as possible. Going vegan, or at least lowering how high you eat on the food chain, is one of the fastest way to do that. (Cutting back on, or giving up, flying and most other long-distance travel is another.)
If you or others have a faster way to do it, go for it.
Also, most 'inhospitable' lands are in fact 'hospitable' to some species. Why don't we leave some of the world for non-humans, and for species not directly serving human culinary desires?
By the way, committed meat eaters should be the most enthusiastic about others going vegan/vegetarian...such moves will make more meat available for them, and probably at a lower price!
Also note that veganism is on the rise world wide:
http://www.huffingtonpost.com/2013/04/02/interest-in-vegan-diets-on-the-rise_n_3003221.htmlAccording to the link below, as many as 41% of Americans ate less meat over the last 12 months (but note that it's a March 2015 article).
http://www.foodnavigator-usa.com/Markets/Vegan-is-going-mainstream-trend-data-suggests