Trump is dead serious about taking Greenland and wanting Canada to become the 51st state. They are gearing up for a world impacted by climate change and embracing imperialism. Canada is a breadbasket and will be relatively insulated from the worst of climate change. Greenland is needed due to melting caps opening up new channels of navigation and accessibility to minerals/raw materials. They want the American public to be in the dark about the severity of climate change but their foreign policy decisions acknowledges its implications.
With that said they're going about this whole thing foolishly. The US annexing Canada and Greenland will make us a pariah state and make us no better than Russia. The US should be strengthening relationships with allies in preparing for whats to come. Instead we're going fully rogue and turning the world into a far more unsafe place where military might makes right.