Here's a taste at least[1]. You have both a former VP and the US military warning of climate influenced political instability. These ideas are definitely out there and circulating as part of the decision making process on things like homeland security. Books are written[2] and think tanks produce analyses[3]. Not everyone in our governments have goldfish attention spans and their information sources go beyond news-entertainment. I would never claim this is the only factor, but the ideas are out there and taken seriously.

[1]https://www.independent.co.uk/environment/brexit-climate-cha...

[2]https://www.amazon.com/Storming-Wall-Migration-Homeland-Secu...

[3]http://www.ourenergypolicy.org/wp-content/uploads/2018/01/Is...