I ask the question and share the facts because I am a scientist; I take a stand because I am a parent and grandparent

I know that climate change is a hot-button issue (pun intended). But sometimes you have to speak out.

My research is on the modern carbon cycle and climate dynamics. It’s a path I’ve been on since graduate school more than 30 years ago. Truth be told, when I chose these topics to work on, I figured that our leaders would have done something about greenhouse gases and climate change 20 years ago, and I could be off doing something else.

I’ve always subscribed to the approach that taking on new challenges in work is both healthy and invigorating. But in my research life, I’m still doing now what I started doing in the late 1980s.

Today, atmospheric CO2 is over 400 parts per million, levels not seen in millions of years on our planet. And physics tells us that we now have enough greenhouse gases in the atmosphere for a much warmer planet with very much higher sea levels.

And while we are beings who deeply value free will, we simply cannot change the laws of physics. Current climate change is like a chugging freight train that is gaining speed all the time. We don’t know how it is going to stop, but we know we have to try and stop it.

This is a threshold moment in our relationship with the planet: Are we going to push the climate system so far out of balance that we threaten to radically change coastlines, create hundreds of millions of refugees and the political turmoil that follows, and leave our children and grandchildren to clean up the mess we created?

These are questions I pose when I speak publicly about climate change, as I did in the new HBO documentary Ice on Fire, which premiered this month.

Why do I speak out? Certainly not to annoy our alumni. Yes, I am a college dean, but I am also a scientist. Scientists have an obligation to communicate their findings, and that obligation is more pressing when the stakes are, as with climate change, existential. And I am also a parent and a grandparent who cares deeply about future generations and their well-being. When I think about them, I just have to speak out.

James W.C. White is interim dean of the College of Arts and Sciences. White, a professor of geological sciences is among a handfull of CU Boulder scientists who have been designated "highly cited researchers" by Clarivate Analytics, which recognizes researchers whose work ranks in the top 1% of citations for their field.