Listened to Saul Griffith (author of
Break Glass Book) speaking on a podcast recently about how to move to a carbon neutral economy in the US. He was challenging the meat argument, making the points that the figures are often fairly significantly overstated and it's not an option to simply stop eating meat and save those CO2 emissions, you have to eat something so you'll increase your consumption of non-meat foods which require many of the same CO2 generating processes that meat creation does (repurposing land from foresty to fields, fossil fuel use on farms, processing, transport to retails outlets).
The EPA in ‘‘Inventory of United States Greenhouse Gases and Sinks: 1990–2007’’ estimate that the entire argi industry in the US generates 5.8% of human CO2 created emissions. Livestock specifically represented 2.8% of the total. For comparison transportation is 26% of emissions in the US.
In summary his argument was that meat emissions are overstated, even we stopped eating meat altogether we'll start eating veg/grain, so the net gain will not be the full 2.8% by a longshot. He also feels meat eating is so culturally engrained that trying to persuade people to stop eating meat is likely to turn them off climate change action altogether.
Food for thought.