"The burning of fossil fuels for energy and animal agriculture are two of the biggest contributors to global warming, along with deforestation. Globally, fossil fuel-based energy is responsible for about 60% of human greenhouse gas emissions, with deforestation at about 18%, and animal agriculture between 14% and 18% (estimates from the World Resources Institute, UN Food and Agriculture Organization, and Pitesky et al. 2009)."

I feel as though a lot of deforestation from animal agriculture, so I add a few points to those last two numbers.

This second article I will quote from and link talks about the Mass extinction right now, "Finally, assuming that Caribbean reefs have one-twelfth of all reef species, they calculated total reef diversity figures of approximately 1,656,000, 2,163,000, and 2,594,000 species, respectively. If the less conservative estimate of total reef area in the world that Reaka-Kudla ( 1997) used (600,000 km 2) is applied to these calculations, the figure for reefs overall rises to approximately 3.2 million species."(Full Article Here)

I am glad you have a good relationship to the food/animals you eat and I am not telling you to stop either. I would rather have you influence more people to consume meat like yourself. I think this second article puts an interesting perspective on the big picture.

Finally, if you set up a habitat livable for these 200 heritage breeds, would they not be able to survive?