It isn't the large scale harm we are looking after. If we know such harm exists then it would be too late to step in. Here is a documentary of what happen to t

It isn't the large scale harm we are looking after. If we know such harm exists then it would be too late to step in. Here is a documentary of what happen to the millions or even trillions of plastic flooding around the ocean. https://www.youtube.com/watch?v=ulkY7mOkdqs https://www.youtube.com/watch?v=ulkY7mOkdqs Is this a small harm or big harm? What if an entire population on some distant island gets wiped out because of that? How would we know? Even for a small number of death, we are responsible to help clean up the ocean as much as possible, just as we are responsible for cleaning up all the space debris. Is it right that we just blow up a satellite and not worry about the orbital debris? If it's not right, we don't do it, regardless of how small the harm is. If we overfishing, we ought to mark certain part of the ocean free from fishing.