Why can't you believe it?
I mean, a lot of the noted vegetarians of the last 50 years have been involved with environmental movements.
Probably can't believe it because, although the livestock indsutry emits significant amount more greenouse gasses than ALL transport, is the major cause of deforestation, is the biggest waste of water.... groups claiming to be fighting for the environment won't go near it..... it's actually sickening to think about it and see.
So isn't it great that some people are making the connection though!