7 ms·

Milk is surprisingly intensive in terms of greenhouse emissions. It is somewhere around 1 to 3 kg CO2-equivalent per kg of milk. Milk protein costs around 95 k

Milk is surprisingly intensive in terms of greenhouse emissions. It is somewhere around 1 to 3 kg CO2-equivalent per kg of milk. Milk protein costs around 95 kg of CO2-equivalent emissions per kg of protein, which is apparently what was used in the production of this plastic [1] [0] https://www.sciencedirect.com/science/article/pii/S0022030222005859 https://www.sciencedirect.com/science/article/pii/S002203022... [1] https://ourworldindata.org/grapher/ghg-per-protein-poore https://ourworldindata.org/grapher/ghg-per-protein-poore

ericd 7mo ago
But to put this in context, the average American family’s carbon footprint per year is roughly 50,000 kg, and one flight is usually on the order of >1,000 kg, or ~300kg/700 pounds of milk, assuming that 3kg CO2 per kg milk high end figure. So if you like milk, there are probably other places you can cut first. Does seem like a lot of carbon for a kg of plastic, though, how does that compare to normal plastic’s carbon footprint?
- beAbU 7mo ago
  >... >1,000 kg, or 700 pounds of milk Why do you mix your units like that.
  - ericd 7mo ago
    Because I'm American, so I use metric in scientific contexts, and weird medieval units in everyday ones :-) I'll edit a bit for clarity for you all who live in more consistent places.
    - beAbU 7mo ago
      I'm not above asking the barber to leave an inch on the top, but then I'm not going to ask him to leave 15mm on the sides. At least keep the system consistent within a sentence :)
      - ericd 7mo ago
        lol fair enough.
scythmic_waves 7mo ago
It's possible to use manufacture whey protein without cows: https://en.wikipedia.org/wiki/Whey_protein#Microbial_production https://en.wikipedia.org/wiki/Whey_protein#Microbial_product... It's not theoretical either. You can buy vegan dairy products made from this method today.
- cogman10 7mo ago
  I'd be interested in knowing what the CO2 emissions were from these. You still need to feed the yeast, so you'll have the CO2 emissions involved in growing a crop associated with this. And if you look at the chart in the OP, you'll see that grain production is about half the CO2 emissions of milk. That's likely part of the milk CO2 production accounting. In addition, you'll need more cleaning/sterilization/mixing. I'd guess that it's lower, but I wonder how much lower. And then there's the other products that generally get thrown into the mix to make up for things like missing fats. For example, a vegan cheese based on bacteria will often include coconut oil, probably to get the same fat profile. Whey is an interesting product in general because it's a waste product of cheese making.
  - Retric 7mo ago
    It’s likely to be vastly better. Feed efficiency is critical when doing these calculations as cows inherently need energy to survive not just produce milk. As such even if you use the same crop two different sources of protein can have wildly different levels of CO2 emissions embedded in their creation. https://en.wikipedia.org/wiki/Feed_conversion_ratio https://en.wikipedia.org/wiki/Feed_conversion_ratio
    - cogman10 7mo ago
      I think it is likely more efficient. That said, cows do have the advantage that the food they consume needs little to no processing in order to produce milk. The yeast needs pretty precise processing of the incoming mash both to make sure a wild yeast strain doesn't make it's way in, and to make sure the yeast ultimately produces the right proteins. You can't just throw in grass clippings into a vat and get whey. You can throw grass clippings into a cow to get milk (though, TBF, I dislike grassy milk).
ahhhhnoooo 7mo ago
But we can also produce milk from yeast now. Perfect Day, for example, produces milk without cows. So it's not out of the question we could scale that up to meet plastics demand.
- 5o1ecist 7mo ago
  [flagged]
  - OkayPhysicist 7mo ago
    To be clear, Perfect Day doesn't make "milk" like plant-based milks (think almond "milk", oat "milk", etc). They bioengineered some yeast to grow whey protein directly. The milk they make (made?) probably wouldn't be considered "milk" in the strict sense (they had to get the fat and sugars from plants), but there's really not a good reason to distinguish between "whey protein from cows" and "whey protein from yeast" when it's the same stuff.
  - qff 7mo ago
    The large diary producers are forcing things that everyone understand what is — “Oat milk” and “Almond milk” — to be called “Oat drink” and “Almond drink”. New terms for things that have existed for decades. Really, we should be calling the OG milk “cow milk” and let the good times roll. Big milk have been pushing questionable health research and narratives for cow milk for quite some time. All this coming from someone (me) who drinks 0,5L of cow milk every day. Yes, yeast milk is milk too. Just like coconut milk.
    - throwway120385 7mo ago
      I thought the reason things are called "Oat Drink" versus "Oat Milk" is because non-dairy "milks" have to be fortified with vitamin D and calcium and the stuff that's labeled a "drink" is not fortified.
  - ahhhhnoooo 7mo ago
    You understand that the product I'm talking about is the same proteins as milk, and is essentially whey, right? I'm not talking about grinding up nuts or grains and calling it milk, I'm talking about engineering yeasts to literally produce the proteins that milk has to create a product that isn't just milk-like, but is literally identical proteins.
philwelch 7mo ago
Where are these emissions coming from? For instance, if this is counting the emissions involved in logistics, none of that inherently or necessarily requires greenhouse emissions—you can electrify trains, tanker trucks, and refrigerators. If this is counting the methane emissions of the cow itself, that’s not a fair or complete accounting. The cow produces methane in her digestive system after eating grass, and the grass grows by, among other things, extracting CO2 from the air. Then the cow burps methane, the methane combines with atmospheric oxygen and breaks down to CO2 and water, and you have a closed loop; the cow cannot belch more carbon than she eats, and that carbon came from the air in the first place.
- psjs 7mo ago
  Methane traps far more heat than CO2 before oxidizing back into it.
  - philwelch 7mo ago
    That doesn’t change the fact that you’re selectively counting only one side of a closed loop process. Methane may be a more efficient greenhouse gas than CO2 but if that effect dominated, we would expect to see the global warming trend start with the evolution of ruminants, not the Industrial Revolution (a time when the North American ruminant population actually declined a significant amount!)
wolvesechoes 7mo ago
I am very much sympathetic to nature conservation, decarbonization, degrowth etc. but really, there are more important considerations at this very moment than shaving few kgs of CO2 by ditching milk. And, as much as some powers try to convince us, not everything can be reduced to carbon footprint.
MagicMoonlight 7mo ago
Oh how convenient. We discovered a clean alternative to oil and now suddenly you have a few “concerns” about the environmental impact of… milk. But oil? That’s fine of course. Completely natural stuff.
deleted 7mo ago
[deleted]

ericd 7mo ago

But to put this in context, the average American family’s carbon footprint per year is roughly 50,000 kg, and one flight is usually on the order of >1,000 kg, or ~300kg/700 pounds of milk, assuming that 3kg CO2 per kg milk high end figure. So if you like milk, there are probably other places you can cut first. Does seem like a lot of carbon for a kg of plastic, though, how does that compare to normal plastic’s carbon footprint?

beAbU 7mo ago
>... >1,000 kg, or 700 pounds of milk Why do you mix your units like that.
- ericd 7mo ago
  Because I'm American, so I use metric in scientific contexts, and weird medieval units in everyday ones :-) I'll edit a bit for clarity for you all who live in more consistent places.
  - beAbU 7mo ago
    I'm not above asking the barber to leave an inch on the top, but then I'm not going to ask him to leave 15mm on the sides. At least keep the system consistent within a sentence :)
    - ericd 7mo ago
      lol fair enough.

scythmic_waves 7mo ago

It's possible to use manufacture whey protein without cows: https://en.wikipedia.org/wiki/Whey_protein#Microbial_production https://en.wikipedia.org/wiki/Whey_protein#Microbial_product... It's not theoretical either. You can buy vegan dairy products made from this method today.

cogman10 7mo ago
I'd be interested in knowing what the CO2 emissions were from these. You still need to feed the yeast, so you'll have the CO2 emissions involved in growing a crop associated with this. And if you look at the chart in the OP, you'll see that grain production is about half the CO2 emissions of milk. That's likely part of the milk CO2 production accounting. In addition, you'll need more cleaning/sterilization/mixing. I'd guess that it's lower, but I wonder how much lower. And then there's the other products that generally get thrown into the mix to make up for things like missing fats. For example, a vegan cheese based on bacteria will often include coconut oil, probably to get the same fat profile. Whey is an interesting product in general because it's a waste product of cheese making.
- Retric 7mo ago
  It’s likely to be vastly better. Feed efficiency is critical when doing these calculations as cows inherently need energy to survive not just produce milk. As such even if you use the same crop two different sources of protein can have wildly different levels of CO2 emissions embedded in their creation. https://en.wikipedia.org/wiki/Feed_conversion_ratio https://en.wikipedia.org/wiki/Feed_conversion_ratio
  - cogman10 7mo ago
    I think it is likely more efficient. That said, cows do have the advantage that the food they consume needs little to no processing in order to produce milk. The yeast needs pretty precise processing of the incoming mash both to make sure a wild yeast strain doesn't make it's way in, and to make sure the yeast ultimately produces the right proteins. You can't just throw in grass clippings into a vat and get whey. You can throw grass clippings into a cow to get milk (though, TBF, I dislike grassy milk).

ahhhhnoooo 7mo ago

But we can also produce milk from yeast now. Perfect Day, for example, produces milk without cows. So it's not out of the question we could scale that up to meet plastics demand.

5o1ecist 7mo ago
[flagged]
- OkayPhysicist 7mo ago
  To be clear, Perfect Day doesn't make "milk" like plant-based milks (think almond "milk", oat "milk", etc). They bioengineered some yeast to grow whey protein directly. The milk they make (made?) probably wouldn't be considered "milk" in the strict sense (they had to get the fat and sugars from plants), but there's really not a good reason to distinguish between "whey protein from cows" and "whey protein from yeast" when it's the same stuff.
- qff 7mo ago
  The large diary producers are forcing things that everyone understand what is — “Oat milk” and “Almond milk” — to be called “Oat drink” and “Almond drink”. New terms for things that have existed for decades. Really, we should be calling the OG milk “cow milk” and let the good times roll. Big milk have been pushing questionable health research and narratives for cow milk for quite some time. All this coming from someone (me) who drinks 0,5L of cow milk every day. Yes, yeast milk is milk too. Just like coconut milk.
  - throwway120385 7mo ago
    I thought the reason things are called "Oat Drink" versus "Oat Milk" is because non-dairy "milks" have to be fortified with vitamin D and calcium and the stuff that's labeled a "drink" is not fortified.
- ahhhhnoooo 7mo ago
  You understand that the product I'm talking about is the same proteins as milk, and is essentially whey, right? I'm not talking about grinding up nuts or grains and calling it milk, I'm talking about engineering yeasts to literally produce the proteins that milk has to create a product that isn't just milk-like, but is literally identical proteins.

philwelch 7mo ago

Where are these emissions coming from? For instance, if this is counting the emissions involved in logistics, none of that inherently or necessarily requires greenhouse emissions—you can electrify trains, tanker trucks, and refrigerators. If this is counting the methane emissions of the cow itself, that’s not a fair or complete accounting. The cow produces methane in her digestive system after eating grass, and the grass grows by, among other things, extracting CO2 from the air. Then the cow burps methane, the methane combines with atmospheric oxygen and breaks down to CO2 and water, and you have a closed loop; the cow cannot belch more carbon than she eats, and that carbon came from the air in the first place.

psjs 7mo ago
Methane traps far more heat than CO2 before oxidizing back into it.
- philwelch 7mo ago
  That doesn’t change the fact that you’re selectively counting only one side of a closed loop process. Methane may be a more efficient greenhouse gas than CO2 but if that effect dominated, we would expect to see the global warming trend start with the evolution of ruminants, not the Industrial Revolution (a time when the North American ruminant population actually declined a significant amount!)

wolvesechoes 7mo ago

I am very much sympathetic to nature conservation, decarbonization, degrowth etc. but really, there are more important considerations at this very moment than shaving few kgs of CO2 by ditching milk. And, as much as some powers try to convince us, not everything can be reduced to carbon footprint.

MagicMoonlight 7mo ago

Oh how convenient. We discovered a clean alternative to oil and now suddenly you have a few “concerns” about the environmental impact of… milk. But oil? That’s fine of course. Completely natural stuff.

deleted 7mo ago

[deleted]