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
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.
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.
Does seem like a lot of carbon for a kg of plastic, though, how does that compare to normal plastic’s carbon footprint?
Why do you mix your units like that.
I'll edit a bit for clarity for you all who live in more consistent places.
So it's not out of the question we could scale that up to meet plastics demand.
That was before multi-billion-dollar companies came up with marketing strategies that manipulated people into not understanding what milk was, instead making them believe that milk is whatever they tell people.
Usually, the reaction to this is "Well, language and the meaning of words change." ... Sure, but that argument comes in complete ignorance of the fact that it only happened, because people with too much money and power can manipulate millions into believing whatever these millions of people are supposed to believe.
Thus now anything can be milk, as long as some profit-oriented company decides that people shall call it milk.
This practise has become the norm to a degree that people will not only generally accept it, but also generally defend it. Pure madness.
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.
Part of the problem with waste management is that we don't really put it in the soil. Your household garbage is mostly biodegradable, but if it ends up buried in a lined pit under tons of other garbage, even paper and orange peels will probably sit there for centuries. I'm not sure it makes much of a difference what kinds or quantities of plastic end up buried in the landfill.
I think the solutions here are more on the supply side than the landfill side. The question there is what are we trying to solve.
Energy use? Most alternative packaging materials are energy-intensive too, so it's less about plastic and more about retail and consumer preferences to have everything individually wrapped and packaged in bags or boxes with colorful graphics, nutrition information, and so on.
Environmental pollution? There, the problem is the plastic that doesn't end up in a landfill. Including our "recycling" shipped overseas.
But I generally agree. The big issue here is we as a society have moved away from biodegradable packing and distribution. I get it, plastic prevents waste and mold. That's why we use it. It's also dirt cheap. It's a byproduct of oil refining (literally cheaper than water).
The ultimate solution to the plastic problem is making plastic more expensive, and the way to tackle that is by reducing oil consumption. Fortunately, that's sort of just naturally happening.
That's 60 kg/person/year of plastic, which is a lot. Or about 4800 kg for a person living 70 years. Obviously, there is wide variation in this number across the human population.
Take a look at something people have been using for eons with saltwater aquariums: bio-pellets. These are tiny beads of PLA that are fluidized to allow high turnover of water through the PLA, this encourages bacteria to colonize and digest the PLA, then break off and move into the water column (the bacteria) and be removed by the protein skimmer. Because of the red field ratio, each 106 mols of carbon from PLA removed this way also removes 16 mols of nitrate, which is a major pollutant in aquariums. It also removes 1 mol of phosphate, a major pollutant as well, but that's not significant. Phosphate is best done by fluidized reactors with ferric oxide
/scnr
I know - long lived plastics are bad. We need some kind of middle ground thats as cheap as the current plastics and doesn't last as long.
Well then it's not plastic is it? Plastic's defining characteristic is that it is not decomposable
But then I got out in the real world, and noticed plastics just falling apart all around -- including stuff that is not intended to fail and which is otherwise still within its useful life.
Like: One year, I bought some used pickle buckets from a local burger joint to use as planters. Within 6 months, they were falling apart: It was easy to break them apart in chunks with my bare hands.
Or the plastics used for cars: They often eventually turn brittle and fall apart, whether interior or exterior. Plastic lenses on USDM cars turn foggy and useless; some types of wire insulation disintegrate. (If we want to talk about environmental cost, can we also talk about the the impact of building a new car?)
In some areas, we once used polybutylene water pipes. These tended to fail and damage homes. There was even a billion-dollar lawsuit about it in the 1990s. It was not good.
Meanwhile, a red Solo cup or a plastic drinking straw, once landfilled, will be there a very long time -- but eventually, they will also decompose.
And the UHMW cutting boards I use in my kitchen will probably outlive my grandchildren's grandchildren before they start falling apart on their own accord.
Plastic isn't always forever, even though some people seem fond of saying that it is. Plastic isn't necessarily cheap, either, even though "cheap plastic" is a common expression -- some plastics are very expensive and resoundingly durable (and there's only partial overlap of these two qualities on a Venn diagram).
The truth is somewhere in the middle, but is rather nuanced and variable and difficult to pin down in absolutes.
But plastic (as a noun) does, broadly speaking, have the material property of being plastic (as an adjective).
Behold, a plastic! holds up a rock
Oil based plastics are generally a lot cheaper than the above though, and they are typically not decomposable. Depending on your use this can be good or bad (I don't want my plastic plumbing pipes to decompose, but other plastics are used up and I want them to decompose)
Also, one of the most widely used plastics is PLA, polylactic acid. Which is made from lactic acid from sugarcane, beets, or cassava, and is biodegradable.