Global warming is making both places more important to global shipping and trade. To imagine the kind of future a hotter, dryer climate may bring, and the geopolitical challenges it will create, look no farther than two parts of the world that Donald Trump wants America to control: Greenland and the Panama Canal.

Republican lawmakers are scratching their heads over President-elect Trump’s ambitions to take over Greenland and the Panama Canal, grand plans the incoming commander in chief put back on the table over the Christmas and New Year’s recess.