Maybe meat faming methods contribute CO2 emissions, but that's a reason to stop those farming methods, not stop eating meat.
Similar to people who hate aircon, people who argue that we should stop eating meat simply reveal themselves as regressives (hating advanced human civilisation, wanting a decrease in energy usage of humanity, which necessarily implies regression and mass death).
(Some people argue that beef contribute methane emissions, which is true however methane is a cycle and contributes nothing to the long-term anthropogenic carbon emissions, the entirety of which is coming from fossil fuels; yet still, the correct response is improving agricultural practices, not banning meat.)
Btw I fully support a carbon tax, as long as it's non-discriminatory (i.e. taxes all fossil fuel usage equally, not meat and/or other "sinful" activities more).