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Comment by vivzkestrel | Hacker News Reader

- stupid question

- if everyone on the entire planet went 100% vegan from tomorrow, will carbon emissions really go down by 60%?

No, because most of the estimates are wonky as hell. For one, calories from silage don't exactly translate directly to calories humans can make use of. Second, most estimates are worst case only and ignore the fact most animals are pastured for some/all of the year on marginal land. Some animals can survive entirely on foraging and waste from agriculture (pigs are a great example).

On the other side, not all climates can produce all the plants required for a balanced vegan diet. Here in Canada, nothing grows for 6 months and what does grow is relatively limited.

The lowest energy system would likely include a reduction in animal products but not a complete elimination, while keeping transportation to a minimum.

Also, just like with energy generation, there's the game theory aspect. If you reduce emissions, will everyone cooperate? What if you suffer only to have someone else increase their emissions anyway? We see this here... We limit our fisheries to try preserve ocean fish, only for Chinese vessels to sit on the edge of our borders hoovering up all the aquatic life...

Carbon emissions from food production may go down about that much. However, those emissions are only about 30% of the total CO2 emissions humans are responsible for, if I recall correctly. So, total CO2 reduction would be about 18%.

and likely other un predictable knock on effects would reduce the benefit, like going vegan would mean more food is available overall, and population might rise in response.

Maybe. Due to not just the caloric availability, but due to eating habits that may influence behavior.

Animals or humans don't cause any net emissions, because the same carbon was captured from the atmosphere in the first place. No new carbon is added. Also, the same amount of methane is broken down in the atmosphere as is created. Increasing co2 is only possible by burning fossil fuels.

No new carbon would be added if we were talking about hunting buffalo on the great plains. But we're talking about industrial agriculture and each calorie produced does have associated fossil fuel emissions

Talking in terms of "carbon" is misleading. Methane is much more potent than CO2. I don't know why you think methane is broken down at the same rate as it is added.

- Cattle release methane

- Forests are burnt to make room for crops/grazing

- Fertilizer for crops for cattle produces nitrous oxide

I do not claim this adds up to 60%, but to suggest it is zero is incorrect.

Methane is broken down with a few years delay, but still the same amount is breaking down as is produced. Think of a long pipe which takes a few years to travel through and it's fed at a constant rate. Total methane in the atmosphere stays constant.

But that still means you have a couple of years with a higher concentration of methane, and given the higher impact this is obviously very relevant, no?

Donald Trump has probably done more to halt CO2 production than any other president, by extending the COVID pandemic and closing the Straight of Hormuz.

Most of the emissions are done by the 100 biggest corporations. That's where I'd start fixing things.

Don't corporations just serve their patrons?

"just" is a weasel word there. Decisions are made and policies are enacted based on a number of factors.

And their investors.

No; patrons express demand for the product, but corporations obscure the negative externalities.

If patrons were shown the real price, we'd switch.

But we're being lied to.

That’s basically a different way of measuring the same thing. These corporations don’t just exist in a bubble, many of them are going to be behind the food production either directly or indirectly (e.g. energy companies providing fuel for machinery).

Food is responsible for about a quarter of greenhouse gas emissions[1]. I agree that it’s not realistic to assume this will be solved individually, more pressure needs to be put on these large corporations from governments, but the quickest way you or I can make our own (individually small, collectively large) impact is by cutting out meat from our diet (specifically beef[2]). We are end-consumers of those 100 largest corporations one way or another.

(Not a vegetarian/vegan btw. I’m not trying to shame, I’m certainly not perfect! I just wanted to share the info that it’s not someone else’s problem. We’re all in this together)

[1] https://ourworldindata.org/food-ghg-emissions [2] https://ourworldindata.org/explorers/food-footprints?Commodi...

That factoid always hides the real issue. The biggest reason that that factoid is true is that the 100 biggest companies includes a large amount of the fossil fuel industry, and that that industry produces most emissions in the world. A company like Saudi Aramco produce 4% of global emissions.

We need to reduce our dependency on fossil fuels.

For full clarity, it's also not the 100 biggest corporations that produce most emissions, but the 100 biggest companies. A massive amount of the global emissions are done by state-owned companies.

> We need to reduce our dependency on fossil fuels.

Unfortunately the United States is currently ruled by a death cult that sees any further push to renewables as capitulation to China and is dedicated to burning fossil fuels until they are fully gone.

See, for example:

https://www.youtube.com/shorts/sbvp4ULD6GI

And while this part is less explicitly stated, I'm convinced they aren't ignorant of the devastating results of this policy, they just intend to profit off it rather than mitigate the harms, thus the stated interest in taking Greenland, Canada, etc.

They know things are going to get really bad, but they also know their own wealth will at least in the short term shield them from much personal exposure to the harm that will increasingly immiserate everyone else.

The smaller ones are most likely less efficient (which blocked their growth). So it'd be a game of whack-a-mole where every hit makes everything worse...

maybe, but only because a lot of people would starve... that's a demand change our food supply isn't currently structured to handle

long term with a proper transition, probably not 60% but likely some lower double-digit percentage (maybe closer to 20?)

We grow a lot of human-edible food for the sole purpose to feed it to livestock, who then spend most of those calories on existing and put a small portion into body mass that we eventually eat.

Sure, that stuff isn't of the same quality as food grown for human consumption, but putting livestock on a diet and diverting some of their food to human consumption would more than cover any shortfall from the missing meat

Yes, only the rich should be allowed to eat the basic food group of natural meat.

That's how it worked for most of human history in most agricultural societies. It's a traditional value.

americans eat more meat than most other countries today, and most humans throughout history

we don't have the distribution systems for it, I promise you it could not be reconfigured overnight (which is the specific thought exercise we were given)

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