If you mean the claim that the beef, pork, poultry, eggs and milk represents a huge emissions footprint, then no. That's not in dispute and it isn't particularly hard to prove that by looking at how much of the agricultural output goes into producing these protein sources.

And that's _before_ you consider the emissions from raising cattle, swine or poultry.

It is also useful to consider the scale of these industries. In terms of biomass, livestock represents more than 30 times the biomass of land based wildlife. In terms of creatures living on land, our food completely dominates the planet.

And if you wonder: I eat meat (in moderation) and I plan to continue doing so as part of a healthy, balanced diet. But that doesn't mean I'm unaware of the environmental cost of what I eat. If we're going to keep eating animal proteins we can't ignore this as the global population grows, and even more importantly, as more and more of the global population is moving up the wealth ladder (see Hans Rosling's talks and how the global population is moving out of the lower income categories).