alt Hacker NewsMilk 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/S002203022...
[1] https://ourworldindata.org/grapher/ghg-per-protein-poore
Replies
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.
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.
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.
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?
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.
It's possible to use manufacture whey protein without cows:
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.