Turns out sea levels may be on track to rise by more than double the unsettling figure climate scientists previously projected, and all within a century. A new study, released Monday, predicts a rise of 6.6 feet by 2100, if global temps warm by 9 degrees Fahrenheit. In that "worst-case scenario," according to CNN, hundreds of millions of people—including residents of New York City—would find themselves displaced as their homes sink underwater.

That's a substantial change from 2013, when the Intergovernmental Panel on Climate Change (IPCC) concluded that, if humanity does not drastically reduce carbon emissions and instead just keeps doing what we're doing, we'll be facing a sea level rise of between about 1.7 and 3.2 feet. But that assessment, according to the BBC, excluded all but the most likely possibilities, meaning it presented a limited picture of our potential for destruction. Instead of looking just at the 17 to 83 percent possibility range, the new expert judgment study (which solicited opinions from 22 ice sheet experts) looked at 5 to 95 percent of the possible outcomes if temperatures increase beyond 2 degrees Celsius (3.6 degrees Fahrenheit).

At that lower level, Greenland's melting ice sheet would be the primary issue, but if atmospheric warming rose to that 5 degree Celsius mark, then you would see East and West Antarctica contributing to the overflow. In that scenario, the sea swallows about 1.79 million square kilometers, or 691,120 sq miles, of land—"an area more than three times the size of California," according to CNN. As a result, some 187 million people would find themselves in an extremely vulnerable position, as islands became uninhabitable, and farmland near water sources became swamped. Coastal cities could just forget it.

The report's lead author, Jonathan Bamber, professor of physical geography at the University of Bristol, emphasized to the BBC that the odds of achieving the 5-degree warming disaster model are about 5 percent, and certainly avoidable if we take aggressive steps to scale back emissions...yesterday? years, decades ago? right freakin' NOW? All the above, probably, so regardless, 5 percent odds should alarm you.

"If I said to you that there was a one in 20 chance that if you crossed the road you would be squashed you wouldn't go near it," Bamber told the BBC. "Even a 1 percent probability means that a one in a hundred year flood is something that could happen in your lifetime. I think that a 5 pecent probability, crikey—I think that's a serious risk."

And I would tend to agree, because remember that 1,600-page climate report the Trump administration maaaaybe attempted to bury in a post-Thanksgiving news dump last year? It put us on a path to achieve that 2 degrees Celsius (3.6 degrees Fahrenheit) of warming by 2040, and also noted that if we fail to take drastic measures to cut down on greenhouse gas emissions—or if, you know, America re-elects a man seemingly bent on doing the opposite of every recommendation handed him by climate scientists—that we could hit 9 degrees Celsius by 2100.

Although climate change is not theoretical, the 9-degree mark currently is. With that in mind, here's a list of 2020 presidential candidates who co-sponsored the Green New Deal, an ambitious climate justice plan for the transition to renewable energy by 2030. To be clear, the GND offers a lofty and probably implausible template, but it's worth knowing where priorities lie.

Senators Elizabeth Warren (D-Massachusetts), Bernie Sanders (D-Vermont), Kamala Harris (D-California), Amy Klobuchar (D-Minnesota), Cory Booker (D-New Jersey), Kristin Gillibrand (D-New York) all co-sponsored the GND, while Mayors Bill de Blasio—who recently championed NYC's own Green New Deal at a Trump Tower rally—and Pete Buttigieg, of South Bend, Indiana, have voiced their support for the spirit of the legislation. Former San Antonio mayor Julián Castro has said: "As President, my first executive order will recommit the United States to the Paris climate accord. We're gonna say no to subsidizing big oil and say yes to passing a Green New Deal." Former tech executive Andrew Yang has said he is "aligned and onboard" with the GND, according to Axios. U.S. Representative Seth Moulton (D-Massachusetts) has also endorsed the GND, and Representative Eric Swallwell (D-California) signed on as a House co-sponsor.

Believers in climate change who have not signed on to the GND, but are either crafting their own plans or believe in the necessity of proactive climate policy include: Beto O'Rourke; U.S. Representative Tulsi Gabbard (D-Hawaii); former Vice President Joe Biden; Governor Steve Bullock (D-Montana); Governor Jay Inslee (D-Washington); Senator Michael Bennett (D-Colorado); Governor John Hickenlooper (D-Colorado); Representative Tim Ryan (D-Ohio); and Representative John Delaney (D-Maryland). And while former Massachusetts Governor and current Republican challenger William Weld has not thrown his weight behind the GND, he has scolded his party and president for deliberately ignoring climate change, a real thing.

Inslee, for whom environmental issues constitute a major part (if not the major part) of the campaign platform, has proposed the Democratic National Committee hold a climate change debate. Another petition has called for all the approximately 1,000 candidates vying for the Oval Office in 2020 take part in a climate change debate. No word yet on whether or not any of that will happen, but considering the circumstances, it certainly seems warranted.