I'm all for better diets and better managing of forests but this is like saying that to put out a fire we really should be concentrating on spitting on it instead of calling the fire department.
[1] - https://www.epa.gov/ghgemissions/sources-greenhouse-gas-emis...
On the same website the EPA global stats show that agriculture and deforestation (largely due to clearing land for cattle grazing) contributes 24% of global greenhouse gas emissions. [1]
I agree that we should be considering all areas of emissions, however diet is something that every individual can decide to take responsibility for immediately without having to lobby huge industries or pass new legislation. Other choices like moving to removable energy and reducing our reliance on transport have a lot more economic and social inertia behind them.
Millions of people are already voluntarily reducing or eliminating their meat intake, and there are plant-based options at virtually all restaurants/chains here in the UK. It's a trend that we should all be encouraging in my opinion, as it demonstrates that society can willingly change its behaviour on a wider scale when presented with reasonable alternatives.
[1] - https://www.epa.gov/ghgemissions/global-greenhouse-gas-emiss...
But the vast majority of government resources (money, attention and political capital) should be expended on reigning in systematic issues, such as outlined by GP: promoting electric vehicles, replacing all coal/oil/gas power plants, carbon neutral shipping and commercial flights etc
The shift of the global economy to sustainability is going to bring down lots of rich people and lots of vested interests, and replace it with other rich people and vested interests. The former are not going to go down without a big fight and only governments (and not individuals) are strong enough to bring them down.
Animal agriculture specifically represents 44 percent of anthropogenic methane emissions, the primary driver of climate change related to livestock, as methane is 34 times more potent than carbon dioxide over 100 years[3]; comprises 44 percent of all anthropogenic nitrous oxide emissions, the most potent GHG[3]; and makes up 75-80 percent of total agricultural emissions.[4]
Looking at emissions by metric tonnes is not just ignorant - it sets the completely wrong precedent of how we should view animal agriculture. Animal agriculture in its current state is dangerous, and should be treated with as much disdain as fossils fuels are.
[0] https://www.sciencedirect.com/science/article/pii/S004896971...
[1]https://www.sciencedirect.com/topics/earth-and-planetary-sci...
[2]http://www.fao.org/3/a0701e/a0701e00.htm (See page 29)
[3]http://www.fao.org/3/i3437e/i3437e03.pdf
[4]http://www.fao.org/climatechange/36143-0fa4483057747f41c0818...
Instead of always shifting the blame to another thing, do what you can within your own means to attack all points at once: eat locally grown food and ideally cut back on meat consumption, particularly beef and fish (fish not for emissions, but due to the absolutely massive environmental damage that fish farming, trawling, and all methods aside from using your own rod do to everything); try to use public transportation, walk, or bike when possible or even try pushing your limits a little bit; don't buy worthless flavor of the month products or needlessly "upgrade" to new items when what you have works fine; and cut back on heating and AC when it's not going to be dangerous or unreasonably uncomfortable.
These are changes people can make in a month. The impact on your wallet with be noticeable fairly immediately, and if enough people actually follow it instead of kicking the can down the road, changes will be seen.
But don't lose track of the engineering constraint here. We not only need to get to zero emissions, we need to get to roughly -20% emissions (relative to today). So the fact that something is "only" 9% of our positive number today in no way shields it from the necessary change that's coming ASAP.
Don't get me wrong, I don't mean that as a justification for behavior policing every little thing at once, but generally anything big enough to register on the gigaton scale we have to have a plan for NOW.
Its too late to do this serially.
If we don't switch to more sustainable diets we risk doing serious harm to the ecosystem and at least massively reducing biodiversity, if not actually placing humans in danger due to our reliance upon said ecosystem.
For me, I don't want to live in a world where wild animals are just a story I tell my kids while we visit a zoo.
That being said, the IPCC never said that transportation, electricity production and industry must be ignored.
Out of all the potential progress that needs to be made, this can come last.
Changing your diet is easier than finding another form of transport anyway?