Perhaps no president in recent times has unified the country, and the globe, as effectively as Donald Trump. In the hours following his rejection of the Paris climate accord, pretty much everyone who didn’t actually work in a coal mine joined in the condemnation.

Few trollers were quite as adept as the new French president, who issued a video urging climate scientists to emigrate from America, but the honchos at Facebook and Google did their part, weighing in with varied admixtures of shock, indignation and disappointment – in fact, Forbes kept a running tally of billionaires expressing their outrage, one of whom, Michael Bloomberg, pledged up to $15 million to help make up for the money America had promised the planet’s poorest countries. Tesla’s Elon Musk and the head of Disney quit the president’s council of CEO advisers, while a senior Vatican official said exiting Paris was a “huge slap in the face for us.”

Politicians across the nation, noting that majorities of voters in every single state (even West Virginia!) opposed withdrawing from the pact, pledged to keep up the fight. More than 300 mayors and counting have announced a compact to fight for the goals of the Paris accord, and 12 states (including New York and California and representing more than a third of the nation’s economy) formed the U.S. Climate Alliance to reach the targets set in the French capital in 2015. In fact, as the director of Canada’s Climate Action Network said, “Trump’s move to withdraw the U.S. from the accord has resulted in the clearest … call for climate action from every corner of human civilization yet.”

Still, one is allowed just the teensiest bit of cynicism when it comes to CEOs and politicians. The head of Dow Chemical, for instance, had expressed his “disappointment” with Trump, noting in grave CEO-speak that “Leaders don’t leave tables. Leaders stay.” It turned out, however, that Dow was a member of a key lobbying group pushing for withdrawal. In Vermont, the hypocrisy was on display the very same day. Republican Gov. Phil Scott, who called the president’s decision “concerning,” said the state would join the Climate Alliance. And yet, the same afternoon, Scott named as the state’s top utility regulator a lawyer who has spent the past few years fighting new wind and solar power.

All of which is to say, just as physics is unlikely to be intimidated by Trump’s bluster, it won’t pay any heed to meaningless pledges by politicians. Physics cares about how much carbon is in the atmosphere. The time for encouraging messages of support for the climate is over – we need action. This has been a problem for years; Democrats in particular have been able to slip by with simple declarations that they “believe” in climate science. But at this point, who cares? Certainly not the swift heating planet. We need serious and immediate commitment to action. Here are three simple criteria for determining whether your local politicians are serious enough to pass the climate test.

They are committed to converting to 100 percent renewable energy

A few years ago, this would have been a hard test, because while it was clear that we needed to drive carbon emissions to zero in order to have a chance of slowing down climate change, it wasn’t clear we had enough alternative power available. Solar and wind were still expensive, and worse, they operated intermittently: When the sun wasn’t shining or the wind ceased to blow, you were out of luck. But over the past decade, these technologies have gotten cheaper and more powerful. From Abu Dhabi to Chile to Mexico to India, solar power costs less to produce than any other form of energy; across much of America, wind costs the same as or less than coal-fired power. As of this year, wind and solar account for 10 percent of electricity in the U.S., and that’s only a glimmer of our potential. Best of all, the sundown problem is being solved fast, as batteries are able to store the energy from the morning sun and the wind from a gusty evening to keep the power running overnight.

For years, the research teams at places like Exxon have not just been lying about global warming, they’ve also been insisting that change must come slowly – that by 2040 the world will still be relying almost entirely on fossil fuel. But innovation has badly outrun those predictions. At the end of May, Patrick Lee, a vice president at Sempra Energy, one of the country’s biggest utilities, addressed an industry gathering: “I am speaking with confidence. . . . We have a solution now to adjust the intermittency of solar and wind energy that is no longer a technology challenge. Now it is an economic decision.” Three years ago, Lee said, his engineering background made him doubt that 100 percent renewable energy was possible – the grid might always need some coal or gas-fired plants to ensure stability. “But today my answer is: The technology has been resolved. How fast do you want to get to 100 percent? That can be done today.”

That the management at his Southern California utility reportedly made him walk back the statement two days later only underlines the point: Technological possibility now bumps up against the everlasting power of the fossil-fuel industry. Recent studies have raised questions about where the last few percentage points of that energy may come from a decade or three down the line, but those are technical quibbles: In 2017, 100 percent renewable is the test of whether a politician is serious.

That’s why Oregon Sen. Jeff Merkley and Sen. Bernie Sanders introduced a bill in April calling for the 100 percent mark to be reached by 2050 (or, hopefully, sooner – if technological innovation continues apace). It obviously won’t pass the current Congress, but on a planet where an iceberg the size of Delaware is about to calve from the Antarctic ice shelf, that number is now the minimum standard for climate credibility. In the words of the great gospel song/civil-rights anthem, “99 and a half won’t do.” The civil-rights theme is no accident, by the way: What was once the environmental movement is now increasingly the climate-justice movement, led by communities that are choking on pollution and workers who know the next burst of good jobs will come from this renewables build-out.

They will work to keep remaining fossil fuels in the ground

Since we’re committing to 100 percent renewable, there’s absolutely no need for any new fossil-fuel infrastructure – no new pipelines, no new frack wells, no new coal mines like the one Trump lauded in his Paris speech. The reason is obvious: If you build them, given the payback time for investments, you’re signing up for another four decades of heating the planet. This would seem an obvious test for a climate-credible politician – it’s been at the heart of the anti-warming movement since at least 2011, when droves of people went off to jail to protest the Keystone XL pipeline. (Full disclosure, I was one of them.)

The movement has won some of these fights: There are bans on fracking in New York and Maryland; Shell retreated from a proposed drilling operation in Alaska after activists blocked delivery of its rigs; and half a dozen proposed coal ports along the Pacific coast are still unbuilt. Even seeming losses aren’t done deals – in June, a federal court ruled that the Dakota Access pipeline hadn’t gone through the proper reviews, a big win for the Standing Rock Sioux, who may yet shut the project down.

What’s interesting is how hard it’s been to get politicians to help. Republican opposition is easy to understand: The party is a wholly owned subsidiary of the fossil-fuel industry (every time there’s a major vote in Congress, Oil Change International- helpfully publishes a list of how much each of the “ayes” has taken from the hydrocarbon lobby). But too often, Democrats go along as well, even if they’re not getting big Texas money. The week before the November election, and the month after security- guards sicced German shepherds on native protesters, Hillary Clinton released this statement about the Dakota pipeline: All of the parties involved – including the federal government, the pipeline company and contractors, the state of North Dakota, and the tribes – need to find a path forward that serves the broadest public interest. For those of us campaigning for her, that waffling didn’t make it easy to win votes – but it was at least predictable, because she and other Democrats were under pressure from the unions that like building pipelines.

It may get easier now for Democrats and progressives to take a stronger stand, because those construction unions have become some of Trump’s most uncritical supporters. Two days after the Women’s March filled the streets of D.C., the brass from the Building Trades Unions visited the Oval Office, where they had nothing but praise for its new occupant. “We have a common bond with the president,” Sean McGarvey, head of the Building Trades, said. “We come from the same industry.”

Happily, the other three-quarters of the labor movement has increasingly sided with the communities fighting against climate change, in part because it’s obvious that renewable energy will supply the jobs of the future. As Naomi Klein wrote in The New York Times, “Today labor leaders face a clear choice:” Back bogus pipelines or “join the diverse and growing movement that is confronting Mr. Trump’s agenda on every front and attempt to lead America’s workers to a clean and safe future.”

For politicians, that choice is even clearer- – and some have responded. Portland, Oregon, for instance, recently banned any new fossil-fuel infrastructure. Philadelphia has plans to become a fossil-fuel “hub” for the Atlantic seaboard, but a broad coalition of scientists and community groups is putting up a stiff fight. In Virginia, even though he lost the primary, Democratic gubernatorial candidate Tom Perriello put a scare into the party’s hierarchy with an insurgent candidacy powered by his opposition to two pipelines and his refusal to be bankrolled by the state’s utility giant, Dominion Energy – in fact, 61 Democratic- legislative candidates across the state joined Perriello in turning down Dominion campaign cash.

They understand natural gas could be the most dangerous fuel of all

For the past decade, the democratic get-out-of-jail-free card for dealing with climate was natural gas – but as with renewable energy, the passage of time changed the situation enormously. It seemed at first blush a victory when wildcatters began finding vast supplies of natural gas beneath America’s soil in the aughts. Because natural gas produces half as much carbon dioxide as coal when you burn it in a power plant, President Obama seized on this bounty as both an environmental and economic windfall.

But two problems soon emerged. One, to get at the gas, you had to frack (that is, explode) the subsurface geology, and soon communities were reporting all kinds of environmental woes – particularly with contaminated groundwater. Second, researchers began to report that the process of producing gas was releasing so much methane (itself a powerful greenhouse gas) into the atmosphere that it was no better for the environment than burning coal. In fact, satellite data suggested that even though carbon emissions had fallen as coal-fired power plants closed, the U.S. was venting so much more methane that total greenhouse-gas emissions may have increased during the Obama years. Just as bad, the flood of cheap natural gas retards the necessary swift conversion to sun and wind, which produce no emissions at all. Ten years ago, natural gas was seen as a bridge; now, it’s clearly a sharp detour away from renewable energy and toward an ever-hotter future.

Standing up to natural gas will be hard, because it’s where the fossil-fuel industry increasingly concentrates its investments. (Exxon, to the surprise of some, opposed the Paris withdrawal – that’s because the company sees its gas business benefiting as carbon cuts go into effect but methane is left unregulated.) And it’s easy for politicians to play rhetorical games here: If you just talk about “carbon,” then gas looks good. But physics, again, is unimpressed by spin. It just adds up all the greenhouse gases in the air, and then it does its thing. Our job is to make sure that truly clean power comes next – we can’t waste another few decades playing around with gas.

So now it’s up to the rest of us to make sure this dark moment produces real gain. If we let politicians simply “stand up for science” or promise to someday reincarnate the Paris accord, then we will never catch up with climate change. If instead the rage that Trump has provoked catapults us into truly serious action – well, that will be the best revenge.