Trash disposal (to regulated landfills, not beaches) is enormously inexpensive and increasing the cost of every item through a laborious return program doesn't improve anything.

Nearly all the plastic humans have made still exists.

The great garbage patch in the Pacific is growing fast. The plastic is ending up in everything. We need to do better.

Make less waste. Use less plastic.

> Nearly all the plastic humans have made still exists.

And it just doesn't matter. It's a tiny amount of mass / volume.

> The great garbage patch in the Pacific is growing fast.

Ocean plastics are almost entirely a consequence of (particularly Indonesian) fishing net waste, not Western consumer products disposed of in managed landfills. The "great garbage patch" is also very much overstating the scale of the problem; it's a slightly higher plastic density region of ocean.

> And it just doesn't matter. It's a tiny amount of mass / volume.

Are you sure? It’s getting into food. We are eating it and drinking it, and it’s getting more prevalent.

It's not getting there from competent landfills, and there are many many competent landfills. An elaborate return program wouldn't do better.

Go on, give us some numbers.

Because 7Bn people multiplied by a few kg/year doesn't seem trivial to me, but sounds like you can prove it.

The main thing about plastic is that it’s made from oil, and oil already exists in the ground. Putting it back into the ground is basically neutral minus the pollution involved in manufacturing.

Right, but there's ground and there's ground.

Geological strata vs shallow landfill sitting above aquifers and subject to near-term erosion.

Disposing of this stuff in deep mines seems like it'd be fine, unfortunately we haven't yet, at a society/economy level, found the discipline to do so. Presumably after a few mya of heat and pressure it'll be indistinguishable from other petrochemicals (which aren't particularly nice to begin with).

I don't think disposing of stuff deep in mines would be a good idea as it would be easy to contaminate the ground water. Modern landfills are generally well engineered and don't contaminate the surroundings too badly.

It doesn't go "back in the ground" though, does it? It gets scattered all over the ecology. When you take something that was buried deep and scatter it all over the surface - especially when that something is oil - that's usually considered an ecological disaster. Deepwater Horizon, the worst oil spill in history, has had catastrophic effects on the local wildlife, and it is still dwarfed in scale by the amount of plastic annually strewn to the four corners of the Earth.

7 billion kg at the density of water would fit in a cube 200 m on each side.

All the plastic ever produced could be stuffed back into one medium size coal mine. There are thousands of such mines and they are already ecologically disruptive.

It's a large amount when you think about the logistics to move it around the world, but a small amount compared to the total amount of stuff we take out of the earth.

We've produced 6-8 billion tons of plastic/plastic waste and its bulk density is much lower than water

https://ourworldindata.org/grapher/global-plastics-productio...