Bruce Hamilton from Sierra Club has a silly moment in Cowspiracy.
The EPA doesn’t place livestock as the leading cause of GHG.
https://www.epa.gov/ghgemissions/sources-greenhouse-gas-emis...
Livestock are an important source (just not the most important). Documentaries with an obvious angle also purposely edit their footage to cast their villains in an unflattering light.
There’s also a good blog post by the Union of Concerned Scientists about this very claim.
https://blog.ucsusa.org/doug-boucher/cowspiracy-movie-review
Although, environmental destruction and pollution, water use, pretty high. So it was funny to see a major face of Sierra Club being totally oblivious to it.
For me, personally, what also matters is the relative ranking of impacts. I did some research into this and here are the top personal contributors to GHG emissions (presumably for a person living in a developed country).
(All figures in tons CO2 per year)
Have one fewer child: 58.6
Live car free: 2.4
One less transatlantic flight: 1.6
Buy green energy: 1.47
EV to car free: 1.15
Plant-based diet: 0.82
etc...
The interesting thing is that based on this analysis, on average our transportation usage far dominates the plant-based diet aspect.
Popular press (with some interesting follow-on thoughts about how most of the emissions are produced by the wealthy). https://www.vox.com/energy-and-environment/2017/7/14/1596354...
original paper here: https://iopscience.iop.org/article/10.1088/1748-9326/aa7541/...
They say cattle respiration should not be counted because what CO2 comes from cattle respiration would have come from soil respiration.
But it seems to me that the two operate on vastly different timescales : according to wikipedia, "Carbon stored in soil can remain there for up to thousands of years before being washed into rivers by erosion or released into the atmosphere through soil respiration."
So it would seem to make sense to count cattle respiration as added CO2.