Oh, they will certainly evolve to eat plastic by themselves at some point. Some already do.

During carboniferous, microbes couldn't eat lignin from wood. Now we have fungi and all sorts of bacteria (including those termites host) that can make use of it.

Every time I rake leaves or clean up after my plants, I think of the sheer amount of trash that plants create, from discarded leaves to flower petals. We’re fine with it of course because something figured out how to eat the trash.

I think that's a key point: you need to leave enough trash that it's evolutionary interesting to make use of that resource. It needs to provide a competitive advantage. Not sure we're here yet, though some environments like dumps could cross that threshold.

Oh, and time. Life is more diverse now than it was during carboniferous, but it still took millions of years for bacteria to learn how to digest lignin/wood.

carboniferous, that period didn't have CRISPR. We could give that evolutionary path a little push along if we like.

I'd rather we didn't mess with that stuff. You can't uncreate a microorganism, we have no realistic way of controlling them (see under MRSA) and our world is made of plastic. I'd rather not have it fall apart because some lab assistant made an oopsie.

Sure, that's something to consider before releasing stuff like this in the wild, especially if it can mutate and start attacking something else.

My point was: whether we use GMO or not, such a thing might happen naturally.

There is also a chance that such a mutation does not offer much competitive advantage if other nutrients are easy to find, and the mutation disappears. I wouldn't bet on it though, given the number of ecological niches that exist.

I'm sure microbes will learn to eat plastic eventually. But if we don't mess with it, they have plenty to eat already, so the pressure to specialize on plastics is low, and we have plenty of time to live our happy lives before that becomes a real problem. But now we have tools to accelerate these processes greatly. And there's a real potential for us to screw ourselves up - and we are way not advanced enough to un-screw-up ourselves if that happens. We're like a person living in a paper city who discovered fire, but doesn't know yet how to make anything fire retardant. It's not a good place to try stuff just to see what'd happen.

Instead of the grey goo apocalypse everyone worried about with nanites, we'll have a green apocalypse.

Why is this not a problem with wood? We have learned how to protect wood from microbes. We will learn the same thing for plastic as well.

It took a long time for fungi to evolve to consume wood (bacteria too). It took 60 million years for this evolution to take place. Sounds like plastic might be on a faster track according to this article.

Basically wood cells are hard to penetrate, don't provide a food source if they've been air dried, and even in cases where fresh cut wood isn't dried quickly, organisms don't cause enough damage to affect wood's strength. Pretty fascinating stuff.

> Deterioration Without Decomposition. When fresh-cut lumber or veneer is properly air-seasoned, the stored food materials in the sapwood are soon depleted by the respiratory processes of the wood parenchyma cells themselves. If drying is delayed, however, the fresh-cut wood can be invaded by so-called sap-stain fungi and algae, or by bacteria and molds that develop over the surface or penetrate deep into the sapwood by growing through the ray cells from one wood storage cell to another. These organisms use the contents of the wood storage cells as food and thus do not affect the strength of wood seriously; they primarily discolor the wood or alter its permeability. When fresh-cut wood is kiln-dried immediately, the living cells of the sapwood are killed by the heat and the reserve foods are retained in the wood storage cells. If kiln-dried wood becomes wet again, these stored foods can again become substrates for growth of discoloring fungi and bacteria.

Source: https://www.fpl.fs.fed.us/documnts/pdf1984/kirk84a.pdf

"These organisms use the contents of the wood storage cells as food and thus do not affect the strength of wood seriously; they primarily discolor the wood or alter its permeability."

Discoloration only? But then what is rot?

The linked text is titled "Biological Decomposition of Solid Wood". It's pretty fascinating, and also covers destructive decomposition mechanisms.

FWIW, we avoid this problem with wood by pressure treating the wood with poisonous chemicals, so mold and other organisms can eat it.

Another common method is to protect the wood with a layer of plastic (polyurethane, paint, etc). That's evidently out the window...

I thought the way we prevent wood rot is keeping moisture away, painting it is one way to prevent moisture away

That is a common technique I mentioned. Most paints and finishes we use on wood are in the plastics family. So if microbes can eat plastics, that line of defense becomes a lot weaker.

The other way we protect wood is to acknowledge that it will get damp, and pressure treat it with poison so that mold can't grow on it.

I don't think we'll have a huge problem in general but things will become less convenient. Water based paints any consumer can buy at any point and use without worrying too much and get decent results in any color you name are great.

We might have a harder time with traditional limewash. It is rather caustic and takes a long time to prepare. And while you can achieve different colors with it, it's not the uniform easy perfectness modern paints have. It also has to be re-applied periodically, so it's not as hands off.

It's a bit like gyp rock. You can buy these sheets that go up quickly and easily even for the lay person (I've built a wall). Lathe and plaster existed before that and worked well enough. It's a lot more work though.