Once upon a time in the mid-20th Century, when their city saw the pea-soup-thick midnight darkness that enveloped downtown streets at noon as a sign of manly economic health, the recent remarks by Pittsburgh’s mayor would have seemed the height of heresy — like rooting for Philly’s Eagles to defeat his hometown Steelers on a cool autumn Sunday. Even in 2019, Bill Peduto ruffled more than a few feathers when he uttered just 10 words.

“I oppose any additional petrochemical companies coming to Western Pennsylvania,” Peduto told a recent conference attended largely by environmentalists. The mayor’s message was: Forget the promise of returning some (but not nearly all) of the good-paying, union jobs to a region that once saw black smoke and orange flame as its life bloods, or any dreams of construction cranes lining the banks of the Ohio River for a The Graduate-style future of “plastics.” The fate of the planet, he warned, isn’t worth trading for some short-term blue-collar growth.

The leader of Pennsylvania’s second-largest city said it makes no sense for western Pa. to “invest in 19th century industry that costs us the opportunity to bring 21st century industry to this region.” It’s easy to understand the frustration of a big-city mayor like Peduto. He’s committed staff and planning resources to stave off climate change, only to see Shell Oil constructing a $6 billion ethane cracker in neighboring Beaver County that — despite supposed state-of-art-pollution control — will emit 2.25 million tons of carbon dioxide every year and, thus, wipe out all of the carbon reductions that Pittsburgh had planned through 2030.

Peduto and the Pittsburgh region’s small but growing band of environmentalists have good reason to feel frustration — locally, and globally. The Shell plant — hailed as a job creator (up to 6,000 construction, 500 permanent) by politicians including President Trump and Gov. Wolf, The Most Liberal Governor in America™ — may be just be the tip of a petrochemical iceberg in the Ohio Valley, with Big Oil icon Exxon-Mobil looking for a nearby site and several more proposed plants to make plastics from fracked gas on the drawing boards.

The race to re-create Louisiana’s notorious “Cancer Alley” right here in the Keystone State is happening at the same time that the world’s climate scientists have released their most dire report yet. On Monday, a UN panel warned that the fight to stave off the worst effects of global warming has grown more desperate, in part because big nations like the United States and China have actually seen greenhouse-gas pollution increase at a time when shrinkage is required. The UN’s environmental chief said bluntly that humankind needs “to catch up on the years in which we procrastinated.”

Pennsylvania — which produces about 1 percent of the entire world’s greenhouse gases — has been Procrastination Central. While the GOP-controlled Legislature soaks in climate denial, Democratic governor Wolf has become the poster child for policy schizophrenia, throwing tax breaks at the Shell monstrosity at the same time he promises a 26 percent cut in carbon emissions in just six years, while pushing to pay for state infrastructure with a tax on fracking, which sounds like a good idea but locks in large-scale fossil fuel production for 20 more years.

It takes courage to make a principled stand like Pittsburgh’s Peduto, who’s been beat up by business and Big Oil and Gas lobbyists, nominally Democratic-leaning labor unions, and his Trumpian hometown newspaper. More folks should listen to his message, which is that environmentalism is a long-term job creator, since a) the firms that create 21st century-style work want clean cities and b) clean energy, such as solar and wind, is driving an understated jobs boom. What’s more, Peduto’s words are a reminder that climate change can be fought locally as well as global.

That’s a great lesson for Philadelphia, which is fighting its own fossil-fuel challenge. What happens in the coming weeks at a 1,300-acre South Philadelphia site — an oil refinery since the Ulysses S Grant administration, where an explosion and fire this June almost became a major lethal catastrophe — may determine where Pennsylvania’s largest city can become a climate leader, or continue to suffer from a bipolar energy agenda.

On Tuesday, city officials released a report from a task force studying the future of the Philadelphia Energy Solutions’ refinery which now rests in a federal bankruptcy court. The report outlined the city’s aspirations to make the site as “green” as possible under presumably new owners — while still providing jobs, of course — and less likely to cause an environmental disaster. But with the sprawling Schuylkill River facility in private hands, and with bankruptcy court tasked solely with getting the most bang for the buck, Philadelphia’s hands are mostly tied. As my colleague Andrew Maykuth reported, the city’s good-intentioned desire for something “cleaner, safer, and better for Philadelphians” probably won’t be enough to end fossil-fuel refining in the city, for now.

Look, there’s no question that a corner has turned in Philadelphia. As recently as the mayoral election of 2015, there was an almost a religious fervor for making the city into an “energy hub” for fossil fuels; the soon-to-be Mayor Kenney put then-refinery CEO “Fossil Phil” Rinaldi on his economic-development advisory board, as a Kenney spokesman told me “clean air doesn’t do our citizens a lot of good if they can’t afford to live here.”

Four years later, no one’s talking about that “energy hub” anymore. And Kenney — so secure in winning a second term that he could travel to Copenhagen for a global climate summit a couple of weeks before Election Day — has promised that Philadelphia will cut its carbon emissions by 80 percent by 2050. These kind of lofty but vague and far-off goals have come to define America’s response to a planetary crisis. The showdown over the South Philadelphia refinery is a test of what we can actually do in the present.

One of the city’s leading environmental groups, the Clean Air Council, recently partnered with Drexel University’s Lindy Institute for Urban Innovation to launch a study of long-term uses for the South Philly site that could make use of its prime real estate in some greener way than continued oil refining. The council’s executive director, Joe Minott, told me he fears that by “hanging on for dear life to fossil fuels, we’ll miss an opportunity.”

Critically, there’s a growing consensus among environmentalists like Minott and city officials that Philadelphia — which asked for and was given a seat at the refinery bankruptcy hearings — can influence that future by making it clear that pending governmental actions will favor green facilities, not polluting ones. That includes things like tougher air-monitoring rules, proposed restrictions that prevent any new owner from using hydrofluoric acid — the lethal chemical that nearly caused a major catastrophe in June — and the city’s considerable influence over matters around zoning and infrastructure.

The Kenney administration should work with City Council to do all of the things, but we — and frankly, the mayor in particular — can do so much more. I’d love to see Jim Kenney one-up Bill Peduto and make some even bolder declarations — that the fossil-fuel era in Philadelphia is officially over, that America’s founding city plans to be its greenest city by the 250th birthday bash, and also forget about 2050 goals because we’re going to do bold stuff that will make your head spin...this year! Philadelphia would never allow Pittsburgh to rough us up inside a hockey rink, so let’s show the state’s No. 2 city who’s the boss in the arena of climate.

This month’s climate tip: So I promised a climate change column every month in 2019 and — human nature being what it is — I’m cheating a little at the end, as this piece launched online in November even though it’s scheduled for print on Dec. 1. Speaking of December, no holiday offers more opportunity to do little things to save the planet than the winter holiday season. Such as ... turkey over beef, smaller cuts, local sources, with recyclable or even reusable wrapping paper and LED outdoor light displays on a timer. (Read some really good tips here.)