The solution to the problem of "other countries have laxer pollution regulations than we do" isn't "well fuck the environment let's pollute more", it's "hey let's make those other countries pollute less". Which, surprise surprise, is impossible right now because of the Trump administration's gutting of the State department.
(I suppose you could technically exert some influence over high-polluting countries via trade deals and tariffs and whatnot, but realistically that just means the goods made by high-pollution methods go to other countries.)
Explain how you make China and India, the two world largest population countries, pollute less? I mean, been tried quite a bit. They will agree in word to shit and still do it to gain an edge.
How do you enforce it?
please stop being ignorant on China's environmental policies