When scientists discuss diet in terms of global warming, part of that discussion include fair wages, ethnic discrimination, inequality, land ownership, ethnic heritage and culture, biodiversity and many other similar topics. All those influence how animal agriculture effects climate change. The global consensus is however very weak the further one goes from fossil fuels. Fossil fuels impact on global warming is an established fact in the global scientific community, as well as the requirement to stop burning fossil fuels. Inequality is also a fairly establish contributor to global warming by itself, but the exact solutions does not have a strong consensus.
Have you not heard of the copious amounts of methane and nitrous oxide associated with animal agriculture? Have you not heard of the associated deforestation and other habitat loss that results in more atmospheric carbon?
Modern high-intensity farming practices such as feedlots and cage chickens - where the majority of the feed is grain and harvested hay - are probably where the conflation enters. There is just as much a need to raise healthy, minimally carbon intensive animals as there is to reduce eating meat. There are farming methods to do this, but change is slow.
Staggering amounts of methane and nitrous oxide. Massive deforestation and other habitat loss (read: reduction of carbon sinks).