[schrodinger]

It's an externality because the entity that sold it to you doesn't have to pay the consequences of dealing with the trash. OP said "dispose of it properly," which could mean a lot of things, all of which are better than leaving it on a beach.

[loeg]

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.

[lostlogin]

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.