I agree with most of your second paragraph. The baseline requirements for immigration are the same almost everywhere. A side effect of that is that there are people today who practically live without immigration restrictions. If you are born into the right nationality, and have the right combination of wealth and/or education, you can move pretty much anywhere you want. I'm soon going to finish grad school and recently ranked all countries in the world on how much I'd like to live/work there. There wasn't a single one where I'd consider going but couldn't.
Looping back to your first argument on environmental problems: Those people who could do the most severe environmental damage are probably in that group who can move freely already. And my impression is that they are already doing a fair bit of environmental damage. A trivial example would be the people who travel to the Alps every winter to do winter sports while merrily destroying the ecosystem there.
Good points and examples but my fear with the 1st argument was more along the lines of home based businesses. "Oh, you say I can't run a home based cyanide process metal plating business in my basement, and dump the waste in the (drinking water) river? Well I'm a job creator and I'll just move to someplace I can!" That kind of thing could cause, oh, about a billion times more damage than an occasional short drive to the alps.
From my old chemistry days, there's a dude active in the 40s to 70s named Max Gergel who pioneered advanced organic chemistry in that era, unfortunately safety and environmental concerns were kind of dark ages, just pour stuff out in the backyard type. Google for "Excuse Me Sir, Would You Like to Buy a Kilo of Isopropyl Bromide" and there's pdfs floating around. Its kinda popular, sorta, in comparison analogy to the BOFH legend. Unfortunately in contrast to the BOFH its all true stories if anything somewhat censored down. I'm pretty sure the old factory site is/was a superfund site although I don't remember.
There's another classic chemist book about "questionable" behavior called the green flame of boron or something like that, basically the manufacturing side of John D Clark's "Ignition" book (which I still own a copy of). That's another enviro hair raiser.
I think the TLDR for pretty much any pre-70s era chemical plant (and, maybe to the current date) is you really don't want to live downwind or downriver if at all possible.
One interesting CS/IT/tech lesson is these guys didn't think they were doing anything wrong which is part of the strange otherworldly appeal of reading their books. Its fun to contemplate what contemporary "data hygiene" practices will be looked back on with horror in perhaps as little as a generation. Sharing executable files? DRM? Tracking? Social networking? Who knows, but evidence from other fields is that things we don't blink about doing now might make our kids recoil in horror decades later.
Looping back to your first argument on environmental problems: Those people who could do the most severe environmental damage are probably in that group who can move freely already. And my impression is that they are already doing a fair bit of environmental damage. A trivial example would be the people who travel to the Alps every winter to do winter sports while merrily destroying the ecosystem there.