Yes, but there is zero shot at doing this versus energy and transportation.

The major limiter of veganism is cultural. People love eating meat. It’s a major source of protein and calories, especially in developing countries. Americans are not going vegan, so it’s kind of silly, in my opinion, to focus on it as a solution.

Compare to building nuclear energy or solar / wind + batteries. China, the US, Europe, and India are all well-positioned to do this. The limitation is political will, which is more difficult than it should be, but definitely easier than convincing a critical mass of Americans to go vegan.

> It’s one piece of many

It is one of the last pieces to focus effort on.

If I stopped eating all meat and dairy it would reduce the world's annual emissions by 0.0000000026%, assuming we can ignore animal quantization and market effects which could easily actually reduce the reduction to 0.

It only makes a difference if a whole lot of other people do that. If I decide individually to do it for the climate even though I will be less happy on a vegan diet and it is not also done by a whole lot of other people I've made myself worse off for no benefit.

To get enough people to do it will require government incentives. It's hard to see how incentives specifically for this could be designed to be both effective and not so unpopular as to get the government replaced at the next election.

If it ever comes about it is far more likely to be as the result of something more general such as a revenue neutral carbon tax. That might raise the input costs for meat production shifting some people to non-meat diets. (They will still mostly prefer meat, but this way they might not blame the government as much).

Compare to other things individuals can do, like switch to EVs. For the vast majority of people with good home charging an EV will generally be as good as or better than an ICE car except that it is several thousand dollars more expensive than a similar ICE car.

That's something governments can incentivize. Subsidize the cost difference and subsidize home charging equipment purchase and installation, and you will get people switching. Not because they want to help the climate and are sacrificing something for that, but because it is an improvement to their current driving setup and it helps the climate.

The biggest wins though are in the things individuals don't directly deal with. Replace fossil fuel power plants with renewables backed with storage that just use gas occasionally for example, and to the user it is all just electricity. You don't have to convince individual they need to change their lifestyle to so this kind of change.

The straw man is claiming that "strict vegan diets" are necessary. People bring up "strict vegan diets" to sabotage climate action. It's a hindrance to achieving the very possible change we need.

how fast do you expect vegan diets to be distributed through society? What is the relation between the expectation of how fast they can be distributed through society and the requirement for speed of distribution to have the desired effect?

Obviously the requirement would have to be significantly quicker than current spread of veganism which would, as you noted, lead to a big dent in the agriculture sector.

How are your calculations taking into account the need to kill off, en masse, cattle and other animals as veganism spreads because they no longer can be considered economically sustaining for the farmer to support them?

I ask because I've never seen any calculation about this! Everybody always seems to think that veganism spreads and the cattle fairy will blink them out of existence.

When I was working for Greenpeace all the holier than thou vegans were all talking about how immoral it was to kill animals for food, not taking into account that once you no longer user those animals for food you need to kill off a lot of them. This taking into account of things always caused me to have a sneaking suspicion that they wanted the animals not to be killed, as if the farmers would be oh well we can't sell you for meat so let's just keep you on in retirement and feed you, but not have you breed, until you die of old age.

Given the influx of sudden and wide spread veganism and the collapse of the meat as food industry, what are the plans for getting rid of the bodies of lots of dead cows? I know what the plans are now with meat as food, cows are butchered, cut up, refrigerated and transported all over the world, but without meet as food none of that will happen because there would not be profit at the end to support it, so please, what is your plan?

Frankly, the whole wide-spread veganism is part of the solution seems to have the weakness of having many problematic moving pieces that are not at all planned for in any meaningful way - that I have ever seen that is.

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.

> Human society existed before money.

Society doesn't require money, but it does seem to require mechanisms for coordinating resources and obligations. Money is one particularly powerful solution to that problem, especially once societies become large enough that most economic interactions occur between people who don't personally know one another.

> And nobody said that a vegan diet would have stopped climates change, they said strict vegan diets, ground based mass transit, dense development & re-wilding, energy transition.

That just makes it less possible.

Consuming and producing less is just not going to happen because there are at least four billion people who don't live the western lifestyle, but want to and there's not much that can stop them.

> Human society existed before money.

That is a very broad claim that can be challenged easily.

Maybe it would make more sense to say: "Money is not everything, and pockets of altruism exist"?

That's simply not true. Politicians have always known how to convince young men to go to war and die for them. Nothing is more selfless. So politicians could also convince people to change their lifestyles for the worse to prevent catastrophe.

The person I'm responding to is the one who brought it up.

I live in a very leftist place, and there were always those at climate events demanding "strict vegan diets" however I didn't see these people out in the general world outside of my little leftist bubble, trying to actually get their idea out there.

I agree with Michael Mann that what most of the public only encounters this idea of "strict vegan diets is a required climate solutions" by hearing it from climate denialists poisoning the well of climate action. But I also see this idea online, and in meat space in very isolated areas.

So the idea of "strict vegan diets" is a real idea on the fringe, but its overall effect on climate action has been to turn people against climate action in the US.

Religious and too poor to eat meat.

Not exactly selling the idea of “strict vegan diet” to a bunch of people with enough cash for meat and incisors in their jaws.

You got any examples of cultures en mass with “strict vegan diets” because lentils taste delicious?

That is not true, most people in India don’t eat meat because they are too poor to afford it and hence malnourishment.

> in India where the vast majority of people either eat no meat or only chicken/fish

That is such a misleading comment. ~80% of people in India consume meat. That "or" is doing some incredibly amounts of borderline lying.

https://www.dataforindia.com/meat-consumption/

https://www.irena.org/News/pressreleases/2025/Jul/91-Percent...

https://www.climaterealityproject.org/blog/why-clean-energy-...

https://www.lazard.com/news-announcements/lazard-releases-20...

My supposed "personal belief" is not normative it is descriptive.

Misconstruing this as normative, and attributing it to a political belief, is your cognitive dissonance trying to reconcile where actual climate action is coming from.

We must understand the world as it is, if we are to effectively change it to a better state.

> Back to reality, west Europe is firmly a social democracy where states impose behavior through law, regulation, and policy, which is topped by a federal system that coordinates policies.

And yet, air travel continues to grow (after a small hiatus due to COVID) and state and EU money will be dumped into a new airport near me, to support more than doubling current capacity, much further away from the city (adding tens of millions of car trips to and from the airport).

I'm simply the looney for not taking the kids on low cost European city escapes.

It starts from the “bottom”: people will talk about it, but will pretty much continue to do whatever the fuck they can afford to do. And Europeans, like Americans, can simply afford to much, while harping about what will happen to the world once the BRICS can afford the same.

Much of Western Europe has increasingly adopted neoliberal policies over the years, I would not call it “firmly” social democratic anymore.

> This personal belief is grounded on an assumption that all mankind follows a neoliberal or even libertarian economic model.

This personal belief is usually coupled to people who have become wealthy following this belief. So it tracks that they would declare any solution that doesn't allow them to continue their plundering impossible.

Jancovici said a lot of stupid things also, although it seems that he recently acknowledged that renewables could make an impact (and not just "l'épaisseur du trait" as he always said). I'm not sure what you mean by "degrowth, relocalisation, lower consumption are all solutions that would work better than technology". People in general do no want to consume less, or buy more expensive stuff created locally, so I think it's easier to create new technologies than to change people mindset, although we probably should try to do both (which we are).

> You're assuming that we keep the same system and that no sacrificing can be made.

No. I am not.

I'm saying that unless the incentive system is aligned with our goals, then it's not actually climate action.

Technologists succeeded at doing that.

People who decided to use non-policy driven political action failed utterly at this. The degrowthers are particularly bad at this, but then all their thinking was muddled and riddled with errors about the reality of the science.

Technology makes the system non-constant. Technology is one of the biggest sources of social change.

I find almost nothing to agree with here.

Renewable energy will power places like Bangladesh towards far greater wealth and prosperity. Aside from the distastefulness of using the term "leftovers" on any group of people, I think its clear that India will become massively more powerful due to their education system, once its further enabled by cheap clean energy and AI.

The US is falling into civil war over stupid culture issues as India is rising. The US is dismantling its education system, its research system, to spend it on wasted defense spending (just in the past few days huge amounts of research money from the National Institutes of Health have been funneled over to DoD. Or DoW, whatever).

Additionally the US's terrible culture war is resulting in slow adoption of cheap energy, which will further lower the US's global position.

There will always be limited resources. If not one, the other. But cheap renewable energy is a great leveler and the US will be leveled far more for its refusal to lead the way with it. India will be hugely ascendant as a massive nation with coordinated, highly educated human resources. Even in the era of AI, perhaps more so, human resources are the ultimate limit on human happiness.

> most of these people will literally be leftovers with nothing left to contribute to the world

A lot of people from bangladesh and india are working in Russia. China and Russia are also investing, and building factories there.

The reality of the situation is if you don’t embrace degrowth principles, the planet will probably do it for you. Think mega-wildfores that cause so much devastation that hundreds of thousands of people die from air pollution, or collapse of entire crops and food supply chains due to drought, or mega-heatwaves that wipe out millions.

Degrowth is coming. And you don’t have a say in the matter.

It's also completely self defeating. Children tend to end up adopting the values of their parents over time. If climate people just remove themselves from the gene pool, their impact on the climate is going to be negligibly small, but there being that many fewer voices of similar values in the future, will have a much more significant impact.

Imagine you're a hyper-partisan and you learn that 'the other side' is spreading messaging amongst themselves encouraging each other to not have children. You're going to be doing backflips, because it's just the collective suicide of an ideology.

Reducing population is a perfectly valid (partial) solution, and it also doesn't mean extinction.

Telling people not to have kids may not be realistic, but... it's also happening already.

A) I’m not a millennial. B) I have kids. C) I used that as one of several sacrifices that can be made to reduce carbon footprint. I would say it is more valid than “being vegan” since that alone may or may not help. Everyone is very ready to wag their finger about the sacrifices they are willing to make but excuse or ignore the ones they are not.

I think your own values are coming through pretty clearly. Understandably, telling a parent they shouldnt have had kids is bound to strike a nerve. Having kids is great. Having kids is also the worst single thing you can do for the environment. Both can be true, and having kids definitely doesn't make someone bad.

However putting kids on a pedestal is silly. If we push our civilization above earths sustainable carrying capacity, we are fucked. In isolation having them is beautiful, in the aggregate it can be bad.

There is much lower-hanging fruit than demanding people alter their diets.

https://www.theguardian.com/environment/2026/aug/31/turkmeni...

> There is no global overpopulation problem over the next century

Sure there is. If the mere act of eating a staple food item causes so many carbon emissions it contributes to planetary-scale climate change, you have an overpopulation problem.

The only time I can think of that democratic populations have made large and sweeping sacrifices have been when they’re actively engaged in total war. And even then, it usually has to be mandated and enforced pretty ruthlessly by the government.

We simply did not evolve as a species to make large personal individual sacrifices today in order to benefit billions of strangers decades in the future. Never going to happen.

The options here are technology saving us, or eco-totalitarian governments controlling a huge portion of the world’s population. Nothing else will work.

This sacrifice involves putting millions back in poverty. I don't think you understand what I'm saying.

It's not ignoring that at all, but I challenge you to go back to the person in China or India that suddenly has amenities and tell him they all have to go away, and everything they worked for over 20 years is gone for "the greater good." You're probably only viewing this from a Western view (already wealthy.)

I never said I believed it was going to save us.

I think it really depends by what you mean when you say vegan.

If you’re eating vegan cheeses and whatnot you’re probably not doing so hot. Or impossible burgers. Or any other manner of “invented” food that is not essentially basic agrarian or hunter-gatherer.

Conversely, wildlife play important ecological purposes and can be hunted sustainably.

Wild life can also be useful in processing things we cannot eat and grows in abundance (grass) into things we can eat (cows).

Everything in moderation…

But we aren’t talking about that individual energy needs. We are talking about everyone’s energy needs at scale.

The economies of scale work differently for billions of mouths vs one mouth.

Let's cut out the middleman of grass here and just directly eat dirt and sunlight.

I never seen vegan who would eat cheap cattle fodder. Usually it is very expensive produce, avocados imported by air etc...

Wildlife hunting has zero emmisions! Even lower emmisions than agricultural products! If you are serious about lowering emmisions, lets push that!!!