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Methane may not warm the Earth quite as much as previously thought

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Re: Methane may not warm the Earth quite as much as previously thought

#281

Post by least »

Moldoteck wrote: post #241
least wrote: post #188

Earlier quoted context omitted.

> this just isn't a rational argument. Taurine, Creatine, Carnosine, and B12 are not found in significant amounts in plants. Heme Iron is much more bioavailable than Plant Iron or Iron supplements. Plant-based diets can also inhibit the absorption of many more nutrients, including Iron and B12. You cannot get the right type of omega-3 fatty acids through a normal plant-based diet, either, you must supplement it with…

Can't you have omega 3 with rapeseed? Also, you make a lot of statements without scientific backup. Afaik balanced pland based diet is healthy

Rapeseed oil has alpha-linolenic acid (ALA) which can be converted into eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), but the process to convert ALA to EPA/DHA is an inefficient one where only about 5-10% of what goes in gets converted. Much of the benefits of omega 3 are found in EPA/DHA and not in ALA, though ALA may also be beneficial.

So, kind of? but not really?

> Also, you make a lot of statements without scientific backup.

This isn't hard to look up nor is it particularly controversial.

> Afaik balanced plant based diet is healthy

It can be. It's just way harder to get the nutrients in the right amounts when compared to someone who is eating meat. Meat obviously has its own issues, but it's undeniable that it's an incredible source of protein that has the right composition of amino acids and has higher bioavailability in the nutrients your body needs. No one is going to accidentally eat a healthy and balanced vegan diet, you will almost certainly become deficient in B12 and potentially a lot of other essential vitamins and minerals. You'll also have issues with amino acids. Meats have a more complete profile that is easily used and absorbed by the body. Individual plant proteins may lack specific ones and the amount and quality of them is lower. Plants also can contain many different antinutrients that make it more difficult for your body to absorb nutrients. This is why plant-based protein powders are a higher quality protein source for vegans than just eating plants.

Re: Methane may not warm the Earth quite as much as previously thought

#282

Post by least »

varjag wrote: post #268
least wrote: post #190

Earlier quoted context omitted.

> Nutritional yeast is tasty and naturally has b12, and most cereals/grains are fortified with it. Taurine, Carnosine, Creatine, and B12 don't exist in significant quantities outside of meat. Nutritional yeast is often supplemented with B12 but the bioavailability of it compared to animal protein is low. You will need to take an actual supplement to get the right amount of B12 your body needs to function optimally. Y…

B12 absolutely exists in many species of fish, it larger concentrations than in meat.

Fish is meat. But even if it weren't, it's still an animal so it doesn't matter when the discussion is about a vegan who won't eat them, either.

Re: Methane may not warm the Earth quite as much as previously thought

#283

Post by codethief »

mattashii wrote: post #274
chalst wrote: post #269

Earlier quoted context omitted.

> Methane degrades to C02 in 1-1 proportion Source? I understood that the long-term radiative forcing of methane was lower than CO2, which is incompatible with this claim.

Presumably, each molecule of atmospheric methane (CH4) primarily degrades through oxidation to 1 CO2 and 2x H2O - this is basic chemestry. Although atmospheric losses to space and capture into oceans and subsequent precipitation into hydrates cannot be excluded as potential atmospheric methane sinks, I expect those to be only marginal at the grand scheme of things.

> Although atmospheric losses to space […], I expect those to be only marginal at the grand scheme of things.

Indeed: https://en.m.wikipedia.org/wiki/Atmospheric_escape#Earth

Re: Methane may not warm the Earth quite as much as previously thought

#284

Post by the_why_of_y »

flavius29663 wrote: post #219
dmurray wrote: post #88

Earlier quoted context omitted.

> the wild population is larger than our own herds. It is not. Domesticated cows make up approximately 35% of the world's mammal biomass. That's the same as humans. All wild land animals combined - all the ones you mentioned and many more - make up around 2%. One source: https://ourworldindata.org/wild-mammals-birds-biomass

before modern man, there were 30-60 mil buffaloes in the US, now there are 30 mil cows. It's kinda a net zero

The "Cattle Inventory: United States" chart here claims there are 95 million, down from a peak of 130 million in 1970s.

https://cairncrestfarm.com/blog/how-many-cows-are-there-in-t...

Re: Methane may not warm the Earth quite as much as previously thought

#285

Post by dotancohen »

adammarples wrote: post #275
chalst wrote: post #269

Earlier quoted context omitted.

> Methane degrades to C02 in 1-1 proportion Source? I understood that the long-term radiative forcing of methane was lower than CO2, which is incompatible with this claim.

The source there would be that they both contain only one carbon atom...

The four hydrogen atoms then... oxidize to form water?

Re: Methane may not warm the Earth quite as much as previously thought

#287

Post by cesnja »

himinlomax wrote: post #262
dataflow wrote: post #234

Earlier quoted context omitted.

> Methane naturally turns into CO2 in the atmosphere After how long? A half-life of a decade , as I understand it? Not exactly the order of magnitude of luxury time we have to spare. > Even if it did increase warming more than CO2 "Even if it did" is strange wording for an established fact. Do you write "even if the sky was blue"? > once methane emissions reach a steady level, reducing methane emissions won't change…

> After how long? A half-life of a decade, as I understand it? Not exactly the order of magnitude of luxury time we have to spare Doesn't matter, if we keep the number of heads of cattle constant, the methane from them in the atmosphere will be constant. If we keep using the same number of ICE cars otoh, the CO2 from them in the atmosphere will keep increasing. We would have to drop the number of ICE cars to 0 to sto…

If the amount of methane in the atmosphere is constant, the CO2 from that in the atmosphere will keep increasing.

Re: Methane may not warm the Earth quite as much as previously thought

#288

Post by tremon »

hkt wrote: post #145
mlyle wrote: post #72

Earlier quoted context omitted.

If you release the same amount of methane per year for a couple dozen years, the methane reaches a steady state where it has a constant value, but CO2 continues to rise. This is because the methane is being converted to CO2 at a relatively quick clip. The timescale for CO2 is larger-- centuries.

Methane - CH4 - degrades to carbon dioxide in the atmosphere. A quick clip, however, it is not: it can take 20 years, during which that single carbon atom yields 20x the global warming potential as part of a methane molecule than it does as part of a carbon dioxide molecule.

it can take 20 years, during which that single carbon atom yields 20x the global warming potential

Actually, it's more than that. The 20x global warming potential of CH4 is based on a 100-year average, which is the yardstick unit of measurement in the scientific literature. But as you say, methane degrades in 20 years so its average-20x contribution happens within those 20 years:

> The IPCC reports that the global warming potential (GWP) for methane is about 84 in terms of its impact over a 20-year timeframe [..] and 105 times the effect when accounting for aerosol interactions

-- from https://en.wikipedia.org/wiki/Atmospheric_methane?useskin=ti...

Re: Methane may not warm the Earth quite as much as previously thought

#289

Post by least »

bigfudge wrote: post #246
cfn wrote: post #242

Earlier quoted context omitted.

So, basically, to avoid eating meat which is what we have been doing for thousands of years, we have to eat all kinds of pharmaceutical products to compensate the deficiencies of a plant based diet. Are we accounting the costs of the production of these products in the comparison, and do we have conclusive, long term studies that suplements are as good as eating natural products? Apparently, the first suplements only…

No. Just eat less meat. We eat far more than is needed even according to the (disputed) literature suggesting meat is necessary for a balanced diet. This doesn’t have to be a binary decision.

Alternatively, we eat as much meat and figure out how to reduce emissions in other ways. Meat production is part of the equation but its focus in these discussions seems largely agenda-based than anything else. It's a convenient scapegoat.

> according to the (disputed) literature suggesting meat is necessary for a balanced diet.

Meat being necessary hinges on veganism being a legitimate replacement. Is veganism legitimate as a full-on replacement? No, it's not. At least not yet. If or when it does become that, then yeah, meat won't be necessary. Right now it's mostly a viable option for relatively healthy adults with a lot of money to spend.

Re: Methane may not warm the Earth quite as much as previously thought

#290

Post by ant6n »

cesnja wrote: post #287
himinlomax wrote: post #262

Earlier quoted context omitted.

> After how long? A half-life of a decade, as I understand it? Not exactly the order of magnitude of luxury time we have to spare Doesn't matter, if we keep the number of heads of cattle constant, the methane from them in the atmosphere will be constant. If we keep using the same number of ICE cars otoh, the CO2 from them in the atmosphere will keep increasing. We would have to drop the number of ICE cars to 0 to sto…

If the amount of methane in the atmosphere is constant, the CO2 from that in the atmosphere will keep increasing.

Well unless there‘s a closed loop co2 - soy - animal - co2/methane - co2. Meat production will involve fossil fuels tho.
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