https://www.scientificamerican.com/article/trumps-border-wall-highlights-the-climate-migration-connection/

President Trump likely would scoff at any suggestion that his desire for a wall on the U.S.-Mexico border has anything to do with climate change.

But researchers in fields from geography to behavioral science increasingly have drawn a connection between global warming and mass migration—and a related rise in anti-immigrant nationalism in both Europe and the United States.