It's true about industrialised farming being a massive contributor to climate problems.
I reccomend everyone watches a Farm for the Future
http://www.youtube.com/watch?v=xShCEKL-mQ8
Veganism isn't necessarily the answer as we couldn't sustain a whole nation on vegan diets, as we cannot grow all the necessary proteins, and I'd rather cut down on meat and pay more to eat local, free range animals.
Plus growing of soya, and palm, two huge parts of a vegan diet, are destroying carbon sinks and are a massively unsustainable crop.
Another interesting link for growing in Britain
http://www.permaculture.org.uk/