I push back heartily on anybody bringing up "strict vegan diets" because it is itself a massive straw man, one that mostly promotes inaction and idleness. Michael Mann's 2021 book, and all the interviews around that time, are probably far more effective than I could be at explaining why it's such a bad idea to bring up "strict vegan diets"

Making money is not the only incentive system in society, but it is overwhelmingly the one that controls emissions. Another key one is regulations around housing, which require lots of driving, that's been built deep into our entire land use, and can not be changed on the time scale necessary for climate action.

Moreover, "making money" is the incentive system in all the world's big carbon emitting economies that controls decisions, from China to the US. Sometimes those incentive systems are based on the costs of technology, sometimes they are based on rules that governments make (e.g. China setting the price for energy capacity markets too high, resulting in buliding lots of coal electricity plants that sit mostly idle...)

As somebody who spends almost all of my political effort trying to get ground based mass transit and dense development, I often advocate for them on climate grounds, but only because climate grounds are convincing politically here. They are rounding errors on climate action, in practice, because new development over the course of the next two decades, the crucial two decades of climate cation, will only be a tiny fraction of our built environment.

There's only one true method for climate action: stop extracting fossil fuels to run soceity, and change all industrial processes that emit carbon to neutral methods, and make agriculture carbon neutral or ideally carbon negative. Strict vegan diets helps with deforestation in Brazil, for those that get meat from Brazil, for example. But the plains of the US used to be covered with bison, before they were slaughtered and replaced with cattle. We need to look at the overall ecosystem, where everything is going.

Talking about "strict vegan diets" when they are not needed is merely a recipe for keeping people from adopting far easier, far more effective, and far more necessary action.