CNN advertised last night's GOP presidential primary debate as an event where "sparks will fly." Like many TV reality shows, candidates already at odds on issues that aren't all that important—like Donald Trump's opinion of Carly Fiorina's face—were pitted against each other at the start.

Eventually, the night settled into more serious topics like foreign and domestic policy. There were personal attacks, a few good zingers, but by the second hour it felt a lot more like a sideshow than a substantive presidential debate. There were simply too many candidates sharing the stage and moderator Jake Tapper struggled to keep things moving forward, giving some GOP hopefuls far more time to speak than others. However, there was one notable difference between this debate and what we've seen in prior elections, which reflects a larger shift in the conversation across parties.

What's changed? Climate. After two and a half hours, Tapper posed this question:

We received a lot of questions from social media about climate change. Senator Rubio, Ronald Reagan's secretary of state George Schultz reminds us that when Reagan was president he faced a similar situation to the one we're facing now, there were dire warnings from the mass consensus of the scientific community about the ozone layer shrinking. Schultz says Ronald Reagan urged skeptics in industry to come up with a plan. He said, do it as an insurance policy in case the scientists are right. The scientists were right. Reagan and his approach worked. Secretary Schultz asks, why not take out an insurance policy approach climate change the Reagan way?

Sen. Marco Rubio (R-FL) argued that the Environmental Protection Agency’s (EPA) regulation of carbon dioxide emissions from coal-fired power plants “will do absolutely nothing to change our climate," pointing out, “America is not a planet.” New Jersey Gov. Chris Christie and Wisconsin Gov. Scott Walker agreed.

I've seen a lot written this morning picking apart each of the statements and their respective responses. Still, there's something else going on—something hopeful—which we should be discussing.

At a nationally televised live presidential debate, these Republican candidates acknowledged climate change is real. That's a dramatic shift.

Back in 2008, we didn’t even hear the words “climate change” or “global warming” mentioned in interviews with candidates. When we launched ScienceDebate, the nonpartisan nonprofit where I serve as executive director, only six of 2,975 questions posed to top candidates in 171 interviews even mentioned either term.

In the 2012 presidential election the situation was much the same. Following one the debates between Barack Obama and Mitt Romney, moderator Candy Crowley of CNN explained her decision to skip a question about climate change thusly:

Now, in 2015, climate change comes up in a GOP primary debate, still early in the campaign season. Meanwhile, Democratic frontrunner Hillary Clinton announced that climate change would be a central issue in her campaign on day one, and she's certainly not the only Democrat talking about the problem.

Over the next year, there will be a lot of debates, forums, speeches, and interviews coming our way. What I'm counting on is a lot more focus on climate change as a serious policy issue than we've ever seen before. And that's a good thing.