You do if you want it to scale to large numbers of people. Affordable lab-grown meat (when we have it) and intermediate solutions like the one in this article (if it's indeed viable) actually work for everybody. Even if we assume that veganism is an okay choice for one's health, trying to convince people to go vegan won't get you very far.

Look at India. There you have more than a billion people who don't eat cows.

India isn't a great place to be looking if you don't want to see a bunch of cows.

They do drink the milk

How’s their carbon footprint?

More importantly: what is their CO2 efficiency? How much GDP and science do they output per unit of CO2?

India is close to Italy in Scientific output [1]: 1040 units vs 1104 respectively.

India's CO2e output is 2.62 billion tonnes, vs Italy 337 million tonnes.

India's GDP is $2.869trillion vs $2.004 trillion.

India's population is 1,336million vs Italy 60 million.

So, India consumes 7.7x the Earth's CO2 budget, but generates only .94x the scientific output and 1.43x the GDP.

Or put another way: the average Italian consumes 2.86x the CO2 as the average Indian, but generates 23x the scientific output and 15x the GDP.

Its really the 2nd and 3rd world who are flagrant wasters of the Earth's resources, not the developed world. Looking at CO2 on a per-capita basis is basically irrelevant.

The inescapable solution to climate change and resource degradation is population reduction of the 2nd and 3rd world to density and intensity levels seen in the 1st world, or perhaps even lower seeing as housing is typically unaffordable in most 1st world countries.

This would suggest a sustainable population of India of about 650 million - which was the population of the country as recently as 1977 [4].

[1] https://www.natureindex.com/country-outputs/generate/All/glo... [2] https://ourworldindata.org/co2/country/india [3] https://ourworldindata.org/co2/country/italy [4] https://www.populationpyramid.net/india/1977/

What an ignorant comment. It just shows a failure of supposedly "superior" Western education, your citizens are deliberately kept uninformed in a desperate attempt to hold on to the power that was unfairly acquired by exploiting much of the world. Your arrogance just cannot bear equality, can you? The days of Western dominance are numbered, you cannot stop it. World power has been gradually shifting eastwards, rightfully. This is the Asian century.

Literally the only thing that matters is CO2 per capita. India's is way low. The low scientic output is a consequence of low per-capita income, it has been increasing and will keep increasing, will definitely cross Italy's (having lived in South Europe I know how the culture here is). It's only a matter of time. India's population has always been historically very high due to fertile lands. It would have been much lower, but 200 years of British colonialism deliberately kept Indians in poverty, keeping birth rates high. And suggesting population reduction - how exactly will you do that? Genocide? War? Try it and see how that goes.

You should focus on reducing your arrogance, racism, denial of facts, and over-consumption. You are not better than others. Learn some morals. The real solution to climate change is science & technology. Our current consumption level is just not inline with the current renewable tech.

You just want to forcefully keep the rest of the world poor so you can enjoy driving your SUVs and eating steaks, while somehow blaming the rest of the world based on some made-up metrics. Guess what that's not gonna happen. Try it if you can.

It is such an unpopular opinion but this is the answer. Humans are selfish. The earth can't sustain 8B+ people. Maybe 2B max with some technological advances for cleaner cars and other renewables.

It's a very arrogant comment indeed. A human's permitted CO2 output should not depend on how much she/he contributes to science or even the GDP.

Anyway, earth could very well sustain even 20 billion people according to Martin Rees (in "On the Future"). It does require that we really reduce our resource usage, however. Going vegan, using virtual reality instead of travelling etc.

Luckily the trends seem to indicate we won't reach more than 11 billion (which is still way too much at today's resource usage) before the numbers go down.

> Going vegan, using virtual reality instead of travelling etc.

Heck, a trillion or more, if we all agree to be suspended in tanks and fed by tubes!

It is rightfully unpopular, because it's not based on facts. The earth could easily sustain 8B+ people if certain countries do not over-consume as they are currently. But you are right, people are selfish, especially these over-consumers.

I think it's better for 2B billion to enjoy life, than for 20B to live under some miserable constraints.

Pretty stupid thing to say. UN predicts 11B humans at peak. Certain new studies predict 9.7B. Global average birth rate is already close to replacement levels.

The earth population that can enjoy life is not fixed at 2B, that's very myopic thinking. We should fund science & tech so that it's possible for 11B people to enjoy life without damaging the planet, instead of blaming the "others" based on racist anti-science attitudes and deliberately keeping them poor by punishing them economically.

https://www.youtube.com/watch?v=nzBAxcJDSsc

https://www.youtube.com/watch?v=QsBT5EQt348

http://www.overpopulation.world/

https://overpopulationisamyth.com/

https://www.gapminder.org/

According to https://edgar.jrc.ec.europa.eu/overview.php?v=booklet2018&ds...

     1.83 tons of CO2 per capita for India
    15.74 tons of CO2 per capita for the USA

Not much (per capita)

This isn't true unless your substitute is to eat nothing.

There was an interesting TV show on British TV (apologies, my Google foo is not able to find the name at this moment in time) where they invited a number of people to eat dishes at a hypothetical restaurant, after each course the tallied the carbon emissions released in creating the dish.

Now obviously being a TV show they had to show some extreme examples but it was definitely interesting when things like imported asparagus dishes released more than the British beef dish. However, things like the wine were even more challenging, wine imported from Australia in bulk tanks was relatively ok, but wines imported after bottling (from Europe for example) where horrible because of the extra transportation.

Too bad there isn't some sort of free market based mechanism that would inherently account for all of these factors without you needing to think about it.

I'm not sure if this is sarcastic, but there quite literally is not a "free market based mechanism" to do this. If there were, there would not be the market failure that we can observe today.

There are plenty of market-based methods for accounting for these externalities though, such as Pigovian taxes.

The "from cows" technically makes it pretty much true. Regardless, it's not a constructive comment for that reason.

Not all sources of food contribute equally to climate change. That is why this article is about cows, and why I commented about cows. They pollute the most.

What do you substitute this? What do you spend your saved money on?

There was a study (Swedish researches I think) that looked at what purchasing effect have form vegetarians as they typically spend less on food than meat eaters. It found while they do have lower green house gas footprint from food, the additional purchasing power brought this back around 2% overall.

So if you look at this holistically, stopping one thing doesn't end its effect unless there is zero flow on from other behaviours as a result.

But how much does it reduce your total carbon emissions from all food sources? Any food source, animal or plant, can have a big impact if the agricultural practices involved are not sustainable. Destroying rain forests for palm oil plantations is arguably worse than raising cattle on pre-existing grasslands and using beef tallow in place of palm oil.

Reducing total emissions is another question.

Checkout the first graph on this site: https://ourworldindata.org/food-choice-vs-eating-local?fbcli...

It shows how eating animals and animal products is far worse. So even if we don't immediately eliminate all carbon emissions, reducing our consumption of animals can have a huge impact.