As Democratic presidential candidates made their way to Miami this week for the first primary debate of the 2020 election, the city hit its highest temperature ever recorded and a wildfire burned through more than 17,000 acres of the Everglades. Communities across the Midwest are still recovering from an onslaught of floods and tornadoes in recent months. More Americans than ever before are worried about climate change, realizing it will soon directly harm them and their neighbors, if it hasn’t already.

Which is why you'd think it's a no-brainer for Democrats to spend one of their presidential primary debates having a national conversation about the climate crisis. After all, every major Democrat vying for the presidential nomination — including frontrunner Joe Biden — thinks we should have a debate focused on climate change. So do an overwhelming majority of Democratic primary voters, according to new data, as do the country's leading environmental and activist groups, like the Sunrise Movement, Greenpeace USA, Credo Action, Friends of the Earth, and 350.org.

Miami, the host city for the first debate, is staring down the barrel of 3 feet of sea level rise resulting from global warming. Yet our political and media establishment has failed spectacularly to give the climate crisis its due airtime: Only 1.5% of questions asked during the 2016 presidential primary debates were about climate change. The United Nations has told us, in no uncertain terms, that we have 10 years left to act to prevent worldwide ecological collapse, so a televised conversation among those vying to lead our country on the topic seems worthy of at least as much airtime as the birth of the royal baby.

It’s a conversation worth having, because there are real differences among Democrats on how to approach the issue. Sure, nearly every candidate says they support the Green New Deal, but what that support actually means differs wildly from one candidate to the next. And big questions remain, like how quickly each wants to move the economy off fossil fuels, what role each envisions for nuclear energy in the decades to come, and how heavily we should lean on mythical tech magic like ‘carbon capture’ to pull emissions out of the air.

My favorite unanswered question comes courtesy of my brilliant friend Kate Aronoff: Would you, as president, consider nationalizing and taking over the fossil fuel industry, given the unprecedented harm their business model is inflicting on the world?

On top of unasked questions, there are also dark spots in each candidate’s record that merit a moderator’s cross-examination. Joe Biden once spoke in favor of the myth of "clean coal," so how much should we read into the fact that his campaign website cribbed language from the coal industry? Why did Sen. Amy Klobuchar defend “safe domestic oil and gas drilling,” a stance at odds with the rapid energy transition scientists say is necessary? Why did Rep. Beto O’Rourke vote to lift the oil export ban as a member of Congress? And why hasn’t South Bend Mayor Pete Buttigieg spelled out a specific proposal to confront the crisis at all?

A climate debate could force candidates to go beyond talking points, and ask each how they’ll overcome fossil fuel industry opposition, ramp down emissions, and scale up renewable energy. It would also have a practical effect, requiring all two dozen Democratic candidates to study the issue thoroughly — a process that could deliver new, creative solutions.

The case for this is obvious, which makes it mystifying to watch the Democratic National Committee and its leader, Tom Perez, offer shifting, unsatisfactory responses to shut down something most of the party wants to do. In a blog post responding to the growing momentum, Perez explained that the DNC’s refusal to host a climate debate wasn’t an expression of bias, but a result of principled unwillingness to put its “thumb on the scale.”

"We learned a valuable lesson in 2016 ... the DNC must remain neutral in both practice and perception," he wrote.

That instinct is admirable, and the DNC should guarantee open, competitive primaries — a courtesy that New York gubernatorial candidate Cynthia Nixon was denied last year when Perez endorsed incumbent governor Andrew Cuomo in the midst of a competitive primary. But what’s missing, in the case of the 2020 cycle, is that activists, voters, and candidates want to see a climate debate not to help any one candidate, but because our political and media establishment routinely ignores the issue. Holding a climate-focused event is something the DNC can do to help fix that, in the face of global catastrophe.

The leading presidential candidates, passionate activists, and a clear majority of voters from the political party that Tom Perez nominally leads all think there needs to be a debate focused on climate change. His job is not the chief of a top-down bureaucracy like the federal agency he led during the Obama administration; his power comes from rank-and-file Democrats continuing to have some measure of confidence in his ability to steer the party. That won’t last if he does not engage with the sense of urgency young people across the country are bringing to the fight for their futures.

The failure of the political establishment to lead on this issue has brought our planet to the brink of collapse. The Democratic Party and its leaders are part of that establishment, and they must grapple seriously with the fact that we have 10 years left to solve this crisis. What will they do to help fix it?