Katharine Hayhoe is an atmospheric scientist and associate professor of political science at Texas Tech University, where she is director of the Climate Science Center. Here is her letter to president-elect Donald Trump, commissioned by The Sunday Edition.

Dear Mr. president-elect:

I think I speak for many in the U.S., in Canada, and around the world, when I say that you've surprised us, you've shocked us, and you've even scared us. Why? Because your words and your actions will affect us all. Your neighbours here in Canada. Policy makers in Europe. Clean energy investors in China. Refugees in Syria.

And climate negotiators who gathered in Marrakesh just this week, to put legs on the hope that was, and still is, offered by the Paris Agreement.

You've given a voice to the fear and anger, the anxiety and frustration of millions of U.S. citizens. That surprises us, shocks us, and even scares us too. But to heal a suppurating boil, we can't just slap some cover-up on it. It has to be lanced. And my hope, from the bottom of my heart, is that by doing so, you will start the healing process.

I'm a climate scientist. Thanks to decades and even centuries of careful research, we know climate is changing, we're responsible, and the impacts are serious. I've helped write U.S. national climate assessments that document how climate change is affecting the country's water, its energy, ecosystems, infrastructure, and even people's health.

This thing is not a hoax; it's real.

But what I've learned, in over a decade spent talking with and listening to thousands of people who disagree with me on climate, is that far more connects us than divides us.

That's what I've learned.

I care, because there are huge and real economic risks of inaction. I care, because it affects national security. The US military calls climate change a threat multiplier. I care, because two thirds of the world's biggest cities lie within just a meter or so of sea level, and we literally cannot pick them up and move them somewhere safer.

And I care because, most of all, climate change isn't fair. It disproportionately affects the poor and the weak, the vulnerable and the disadvantaged, the very people who contributed least to the problem but bear the brunt of its impacts.

I know that in the past, people could simply say, "What's the point, when China isn't doing anything?" But for two years running, now, China has cut its coal use. They're shutting half-built coal plants and they currently lead the world in wind and solar energy. There are solutions and, regardless of what we think about climate, those solutions can grow the economy, clean up our air and water, and ensure our energy future.

But these solutions require two big things: one, that we listen to each other, instead of talking over each other, and two, that we work together instead of tearing each other apart.

Yours in hope,

Katharine Hayhoe