I don't think that's necessarily a very good or helpful approximation. It's very cheap to send vaste chemicals into the sea. It's more expensive to capture them

I don't think that's necessarily a very good or helpful approximation. It's very cheap to send vaste chemicals into the sea. It's more expensive to capture them -- and while it might pollute to build a good capture system, it'll _very_ quickly be outweighed by not sending the stuff into the sea.