Given that President Trump doesn't have any principles or morality, there was part of me that was holding out hope in the weeks following his election that he would end up governing like a non-ideological centrist, doing whatever he thought was popular.

Maybe, since he talked about providing a health care program that would "cover everyone," he would ditch the GOP's preoccupation with repealing Obamacare once he realized that doing so would help nobody and be unpopular. And maybe, since he talked so much about building great things and improving U.S. infrastructure, he could be convinced to get the country building all kinds of stuff that it really needs, like public transportation and renewable energy.

Suffice it to say, those hopes were quickly dashed. While Trump's personal conduct has defied political norms, his policies are predictably reactionary, with not so much as a hint of the years he spent as a Democrat and independent. In the wake of alarming climate news, I'd like to think that the country could unite behind an aggressive agenda to wean ourselves off fossil fuels. Instead, Trump and other Republicans are doubling down on climate change denial.

As tragic as this is, we can't get discouraged. Instead, Democrats need to come up with messaging on climate change that resonates with the American public. They need to couple messaging about the dire consequences of doing nothing about global warming with messaging about the enormous benefits we will reap by aggressively investing in renewable energy.

I think, above all else, Democrats need to reframe the discussion of global warming from an environmental crisis to an economic, public health and national security crisis. Indeed, the military itself has begun planning in anticipation of a crisis that the commander-in-chief refuses to acknowledge. If the crisis is explained in the right way, voters of all political stripes will get behind a major commitment from the government.

Climate change threatens every aspect of the quality of life that we currently enjoy. It's time for the government to step up and make the kinds of big investments in green technology and green infrastructure that we demand they make every year on national security. So I'm glad to see Alexandria Ocasio Cortez and other new leaders in the party make a big stink about this. It's not just the right thing to do. It's good politics.