Plastic-eating caterpillars: An escape from a shopping bag triggers an idea
economist.com
economist.com
Also, polyethylene is one of the simplest plastics and can be recycled quite effectively; so the real problem is getting people to reuse and recycle, and not disposal. Much of it comes from petroleum sources so a nontrivial amount of energy was already spent in its production too.
Frankly, I wonder why (besides the loud sound of the Sunchip bags[0]) that cellulose and other bioplastics aren't utilized more—at least for common and commonly-dispensed items like beer-can rings, food wrappers, and other short-term packaging.
---
The main problem with biodegradable plastics is that they have an inherent "expiry date", the countdown to which begins basically upon manufacturing. Product which could be stored for an unexpectedly long time may start degrading too early and thus become prematurely unusable. Trying to avoid waste myself, I've had a few times where I reused plastic bags which were biodegradable, without being too aware of it, and had some bad surprises when they functioned exactly as designed and disintegrated at the worst of times.
Personally, I'm not a fan of biodegradables --- they seem to be a way for the manufacturers to keep making things which don't last as long, a sort of forced obolescence, under the guise of being "green". Also, overall it probably takes more energy to produce these materials than recycling existing plastics.
That's a good point I hadn't considered. I was referring more specifically to really temporary storage. For instance, those baby spinach containers are usually made of bioplastics because the contents expire rapidly no matter your intentions. There are often other vegetable or grocery-shelf products that might not have long shelf-lives or delayed uses that could utilize the plastics.
Surely we could divide the products into long-life and short-life? I'm speaking mainly to food products here. I don't see the immediate need to eradicate all plastics from use! I regularly keep my grocery plastic bags and reuse them time and time again. I should have been more specific!
That said, it looks like the costs required to manufacture bioplastics are reducing[0]. The problem with non-bioplastics being that many of the refuse that people don't properly recycle will be here maybe long after you and me, or we can just punt it on down the generational-line, but as we've been witness to more recently that doesn't seem to be a great strategy.
---
[0] https://phys.org/news/2015-07-biodegradable-plastic-cheaper-...
If the product is explicitly marketed not to last I see no problem with it. I prefer buying food without excess preservatives, for example.
That leaves two necessary improvements:
1. Decreasing the loudness and crunchiness of the sound, and
2. Controlling the biodegradability of the material.
> Also, overall it probably takes more energy to produce these materials than recycling existing plastics.
Are you taking into account the future cost of de-plasticking oceans, rivers, streams, and other contaminated sites? That should be included too. Deferred costs are still costs.
For some ideas about how to cut waste. A different approach, with emphasis on recycling:
https://www.youtube.com/watch?v=eym10GGidQU
As much as the internet likes to make fun of people like this, I honestly don't see anything wrong with what they're doing. And they look happy and healthy.
> What the “0” landfill means is that no waste is landfilled without pre-treatment…
In 2014 there was only Germany that claims 0 landfill (subject to the above disclaimer) and there's 6 self reported countries that claim below 10%.
[0]: https://www.zerowasteeurope.eu/2014/04/and-the-best-waste-pe...
Polyethylene can be recycled, but depending on the price of oil it's often cheaper to make new things than try to recycle them. Planet money did an episode a few years back that talked about this:
https://www.npr.org/sections/money/2015/03/27/395815221/epis...
"One day it's profitable to recycle a bottle. The next day, some number in the global economy changes and that bottle suddenly becomes trash."
To give one related example, just dumping your trash in the street is cheaper than paying people to come and haul it away but no one seems to make the argument all about cost in that case.
Particularly in the US, propaganda campaigns against the entire concept of recycling seem to have been very succesful. Often these are pushed by libertarians and you can trace the funding back to the Koch brothers who (entirely coincidentally of course) are invested in companies that supply the virgin feedstock materials to make new plastic bags or whatever.
They've also spend millions on anti-EV and anti-solar campaigns two other rival industries where their product is only "better" if you totally ignore externalities.
"Although the biochemical decomposition has not yet been disproven, the sensational report of plastic eating caterpillars at least appears highly doubtful in the light of these results." [1]
[1] https://www.sciencedaily.com/releases/2017/09/170915144156.h...
Read more at: https://phys.org/news/2017-04-caterpillar-bags-biodegradable...
In the case of the mealworms, the digestion is coming from gut bacteria, but it remains unclear how waxworms are able to do it with polyethylene.
In other words, we don't even know if they _digest_ the plastic, or just eat it. If they don't digest it, there's no utility....
https://phys.org/news/2017-04-caterpillar-bags-biodegradable...
>To confirm it wasn't just the chewing mechanism of the caterpillars degrading the plastic, the team mashed up some of the worms and smeared them on polyethylene bags, with similar results
Scientist 2: well how about we anaestetise the caterpillar and use a microfilament to extract the gut contents, then we can ...
Scientist 1: <splat>
Specialty devices exist, but a standard high-speed desktop centrifuge can also be used, as a mouse will generally fit into a 50 mL centrifuge tube.
Generally best not to think about it too much if you like animals, but also like biochemical sciences. But if you're after a specific enzyme that would not be destroyed by rupture of the cell wall, whole-animal sacrifice by centrifuge is the cheap and easy way to get at it.
1. What happens when we remove the "negative" side of using plastic products? Why use less if the worms can eat it all? I'm guessing production and consumption of single use polyethylene products will increase.
2. What if the worms escape control, (like the possums in New Zealand, the farmed salmon in the pacific etc etc) then what sort of new disaster do we have on our hands?
Wait, since when is plastic the main menace to our planet?
>Another question is the composition of their faeces.
Yeah, it would suck if it produced even more CO2 and methane. Even if we can catch the methane to make energy, that's more CO2 that would have been otherwise sequestered.
Once you have collected it bury it, burn it or recycle.
If anything this will just release CO2? or Methane?