I find this comment naive in the extreme. There is a strong overlap between areas subject to the worst impacts of climate change, and areas hosting some of the poorest people in the world (or in their countries).
With respect to the "If" statement around countries closing their borders - seriously, where have you been? The sudden and significant rise in popularity of the far-right in Europe almost coincides to the Syrian refugee crisis, and that was roughly one million people. In my country (Australia) we give our Pacific islands neighbours platitudes while still pushing coal on the rest of the world, and then indefinitely detain those seeking asylum for years (including years after they've been assessed as legitimate refugees). Countries are now proposing the Australian approach to "protect" their own borders. To think that this issue (of climate-change forced population movements) will not cause existential threats for those people is plainly wrong.
With respect to the "If" statement around countries closing their borders - seriously, where have you been? The sudden and significant rise in popularity of the far-right in Europe almost coincides to the Syrian refugee crisis, and that was roughly one million people. In my country (Australia) we give our Pacific islands neighbours platitudes while still pushing coal on the rest of the world, and then indefinitely detain those seeking asylum for years (including years after they've been assessed as legitimate refugees). Countries are now proposing the Australian approach to "protect" their own borders. To think that this issue (of climate-change forced population movements) will not cause existential threats for those people is plainly wrong.