After a 2016 presidential race in which the gathering storm of climate change was shockingly ignored, it was hard to say what was more surprising about the recent 7-hour global-warming extravaganza on CNN. That a ratings-driven TV network like CNN would devote so much time to [checks notes] saving the planet? That there was a mention of Pennsylvania’s Marcellus Shale formation in a presidential forum, and that former vice president Joe Biden felt compelled to blurt out, “I know that!”?

Or maybe that the ground underneath the productive but highly controversial oil-and-gas drilling method known as fracking is shifting faster than an Oklahoma earthquake?

“We’re coming to the end of the bridge,” said Julian Castro, who just a decade ago, as then-mayor of San Antonio, Texas, had touted fracking as a way to produce both jobs and energy that was cleaner than coal. Today, Castro says he now supports local communities fighting fracking on environmental grounds, but he stopped short of calling for an all-out ban.

Others did not stop short. Indeed, three of the four candidates who’ve topped the Democratic polling for much of 2019 — Sens. Elizabeth Warren, Bernie Sanders, and Kamala Harris — promised primary voters they would seek to use the power of the presidency to try to completely ban fracking in the United States, as part of a speedier shift toward clean power sources like wind and solar. Warren — seen by many pundits as having the best chance of passing front-runner Biden — has said she’ll end fracking offshore and on federal lands on Day One of her presidency and then “I will ban fracking — everywhere.”

Could “everywhere” really include Pennsylvania, a state that has, for the most part, since the late 2000s hitched its economic wagon to the natural-gas boom and reaped the benefits of those rich deposits underneath the Marcellus Shale? Does a president even have the power to do that? And even before that day comes, would a call for a fracking ban thwart Democratic plans to win in 2020 by winning back white working-class voters in states like Pennsylvania, who went for a very-pro-fossil-fuel Donald Trump in 2016?

“The idea of a fracking ban is problematic,” admits John Quigley, who heads the Center for Environment, Energy & Economy at Harrisburg University — and Quigley definitely knows the problematic politics of oil and gas. He was Gov. Wolf’s first head of Pennsylvania’s Department of Environmental Protection but clashed with pro-fracking lawmakers and was forced out after only 17 months on the job.

One of the issues, Quigley told me, is that fracking isn’t an energy source but a technology to extract it — hydraulic fracturing, or using a mix of water and chemicals to extract pockets of oil or gas that weren’t extractable before the 2000s. And Big Oil can and probably would develop newer conventional drilling methods that would skirt any fracking ban and keep the fossil-fuel spigot open.

That’s not the only issue a President Warren or Sanders would face in seeking to ban fracking in 2021. Ending unconventional drilling on public lands — tried by Barack Obama, blocked by a judge, and reversed by Trump — will surely be tried, as well as other efforts to curb fracking through regulatory rule-making. But federal courts have been unkind to that approach, and the bench has grown much more conservative under Trump and Senate Majority Leader Mitch McConnell. Congress — which essentially green-lighted fracking under the sway of ex-oilman Dick Cheney in 2005 — could take steps to ban the practice, but Republicans and pro-fracking Dems like West Virginia Sen. Joe Manchin would make that hard.

The thing of it is, as the climate crisis gets worse, the public is turning against fracking — even in Pennsylvania, supposed beneficiary of the surge in drilling. By March 2018, 55 percent of state residents told a Franklin & Marshall poll they now believe the environmental risks of fracking outweigh the economic benefits, vs. just 30 percent who felt the other way around. That was a stunning reversal from January 2014, when 40 percent favored economic benefits and just 37 percent feared the environmental consequences. What changed in those four years?

Some of it might be the almost daily barrage of climate-related stories about strengthening storms (like the rains battering South Texas as I write this), raging wildfires, and melting glaciers. But here in Pennsylvania, many have seen the environmental damage caused by fracking first-hand. This spring, for example, the Pittsburgh Post-Gazette published a searing two-part series that raised questions about childhood cancer clusters near fracking rigs that demand answers.

Sam Bernhardt of Food and Water Action, an environmental group that supports the end of fracking in Pennsylvania, said that some of the communities that are flipping against natural-gas drilling in their backyards are exurban and rural areas that also happened to swing toward Trump in 2016, including some far-flung suburbs near Pittsburgh as well as Chester County west of Philadelphia, where public opinion has turned against the Mariner East 2 gas pipeline.

“They’re really seeing the impact of an overzealous industry coming to their community — and the impact on public safety and health,” Bernhardt told me. That experience has come to supplant the traditional arguments in favor of fracking — that natural gas is that “bridge” to less greenhouse-gas pollution by ending coal, and that we desperately need the jobs (tens of thousands here in Pennsylvania, although estimates vary wildly). The problem is that the political conventional wisdom about the environment almost always lags way behind public opinion.

In the Democratic race for president, the candidates who are scrambling to catch up to Biden know where the hearts and minds of their party’s primary voters are, and that is opposition to fracking. But the former vice president, who wouldn’t push for a frack ban and would instead mimic the policies of Obama, whose “all of the above” energy stance make America the world’s leading fossil-fuel producer, still has the best shot at winning the nod to face Trump next fall.

Here in Pennsylvania, the fight remains mostly between Republicans in the back pocket of energy lobbyists and center-left Democrats like Wolf who don’t want to ban fracking — even with scientists warning we need to get off fossil fuels over the next 11 years — but instead generate revenue by taxing it, and who support the massive, polluting plastics monster in Beaver County, Shell Oil’s ethane cracker. No matter how many jobs or taxes that produces, our atmosphere can’t afford it.

For all the obstacles facing an actual fracking ban, this may be a case of voters taking their presidential candidate seriously, but not literally. That is, they don’t know if the 46th president (or maybe the 47th, the way things are going) can legally ban fracking on Jan. 21, 2021, but they know that what we’re seeing now, with a man in the Oval Office destroying every Obama-era rule on methane, offshore drilling, and fuel standards he can find ... and not caring if the planet gets destroyed along with it, is not sustainable. Which gets to the heart of what you can do to fight climate change right now, which is....

This month’s climate tip: Strike for climate action. Friday brings your opportunity to join hundreds of thousands of students, teachers, workers, and others to halt your normal activities and join a worldwide strike — led by, among others, the 16-year-old Swedish global sensation Greta Thunberg, who’s here in the United States — to force our political leaders to act.

If you’d like to join but are not sure where strike-related protests, marches, or rallies are happening near you, check out the Global Climate Strike website where you can scan their map and also sign up for updates in your area. Here in Philadelphia, that includes a midday rally at City Hall that thousands of students are expected to attend. If you miss out, there’s another opportunity on Friday, Sept. 27 — and plenty of an events in the months ahead. You can sign up for youth-oriented campaigns like the Sunrise Movement.