Jay Inslee is goading his rivals for the 2020 Democratic presidential nomination to back his bid for a primary debate exclusively focused on climate change.

The Washington state governor, who’s made combating human-caused global warming the entire basis of his presidential campaign, launched a petition last week to urge the Democratic National Committee to host a climate-focused debate.

Now he’s pressing the nearly 20 other Democrats running for the nomination to rally behind his proposal.

“We have barely a decade to defeat climate change,” Inslee wrote in an open letter posted on Medium. “And whether we shrink to this challenge, or rise to it, is the central question of our time — and it deserves a full DNC debate.”

Sen. Kirsten Gillibrand (D-N.Y.) told The Daily Beast last week she supported the idea and said a DNC debate on climate change “would show the world that America intends to lead again on this issue.” Julián Castro, the former housing and urban development secretary, joined the call for a climate debate on Twitter.

The DNC brushed off Inslee’s initial proposal last week. On Monday, spokeswoman Xochitl Hinojosa said the DNC “is currently ironing out the details for all 12 debates and will work with the networks to ensure that Democrats have a platform to discuss these issues directly with the American people.”

Climate change came up for just five minutes and 27 seconds during all the presidential debates in 2016. Before winning the Democratic nomination, Hillary Clinton engaged in at least one fiery exchange with rival Sen. Bernie Sanders (I-Vt.) at a debate in Brooklyn, New York, where the Vermont senator lambasted the former secretary of state’s support for increasing hydraulic fracturing, or fracking, and her ties to the fossil fuel industry.

But the issue, despite its ubiquitous effects and unprecedented threat, faded thereafter.

Since then, the consequences of climate change have become horrifying tangible as wildfires and hurricanes racked up historic death tolls in the United States over the past three years. In October, the United Nations warned that, unless world governments cut emissions in half and start sucking carbon dioxide out of the atmosphere over the next decade, catastrophic global warming of 2.7 degrees Fahrenheit is all but guaranteed. The congressionally-mandated National Climate Assessment, put out by scientists at 13 federal agencies, confirmed the U.N. findings a month later.

Already, the issue is getting more play. Sanders, now a front-runner in his second presidential run, is campaigning aggressively on climate change and became an early backer of the Green New Deal movement for a sweeping national industry plan to zero out emissions. Sen. Elizabeth Warren (D-Mass.) kicked off her campaign with calls to end fossil fuel subsidies. And former Texas Rep. Beto O’Rourke’s progressive super stardom lost its sheen as revelations about his past support for oil and gas legislation came to light since he entered the presidential race.

Inslee, meanwhile, is polling at less than 1%. In its write-up of his CNN town hall earlier this month, the environmental newswire E&E News described the governor as “pleading” for more supporters in an attempt “to save his candidacy.”

It’s early in the campaign, and Inslee has yet to flesh out his policy platform. But he’s shown a willingness to embrace some bold ideas that are sure to attract attention, including a call to end the filibuster, a congressional procedure widely seen as a roadblock to any progressive climate legislation. The climate debate proposal marks his most provocative move yet.

“This is an urgent problem, and we can’t resolve it with soundbites and one-off questions,” Inslee wrote. “We need a full debate on climate change. Climate change is at the heart of every issue that matters to voters, and voters deserve to hear what 2020 presidential candidates plan to do about it.”

This story was updated with a statement from the DNC.