Fay pointed to Evan McMullin, the former intelligence officer then mounting an independent campaign in Utah against Sen. Mike Lee, a Republican. McMullin’s signature issue was defending democracy against the extreme right; Democrats had made way for his candidacy by declining to field a nominee of their own. Could there not be an Evan McMullin for the cause of planetary survival?

It was a provocative idea, even an outlandish one. Nothing in recent American history suggests a plan like that would have a fair chance of working.

Australian politics tells a different story.

In Fay’s home country, that strategy has already succeeded. In Australia’s elections last May, a slate of independent candidates stepped forward to challenge the ruling conservatives in some of their electoral strongholds. Nicknamed the teals from the color of their campaign materials, these upstarts battered the sitting government for resisting climate action and helped drive Scott Morrison, then the prime minister, from power.

Aiding the teals was a heavily funded environmental group, Climate 200, which spent millions in the election. It is backed by an outspoken investor, Simon Holmes à Court, and Fay is its executive director.

The September gathering helped mark a new phase in climate politics that has arrived with too little notice. For the first time in memory, green forces in different countries have as much to learn from each others’ breakaway successes as they do from studying their noble failures. They are no longer engaged in a long, tired struggle to make voters care about global warming. They have real momentum on multiple continents, manifested in election results from Washington to Warringah.

Their task now is to drive the planet’s clean-energy transition faster and faster. It is a moment that calls for a spirit of experimentation and a willingness to test the assumed boundaries of electoral politics at home.

In some quarters that process is already underway. A political feedback loop has been developing between environmentalists in the United States and Australia, as well as the United Kingdom — a kind of informal distance-learning program for climate campaigners.

Watching Joe Biden’s 2020 campaign, leaders of the Australian Labor Party absorbed how Biden talked about climate change not just as an environmental crisis but also as an economic opportunity. In Australia’s next election, Labor leader Anthony Albanese promised to make his country a “clean energy superpower” and accused the right-wing Liberal Party of clinging to old thinking and squandering a prosperous future. The message helped make Albanese prime minister, with the teal independents playing a dramatic supporting role in the campaign.

Last October, weeks after Fay’s meeting in Washington, senior officials of Albanese’s Labor Party, including the national secretary Paul Erickson and Wayne Swan, a former deputy prime minister, visited Liverpool for the British Labour Party’s annual conference. Meeting with advisers to Keir Starmer, Britain’s opposition party leader, the Australians outlined their winning blueprint, including a climate message that put conservatives on defense and blunted the usual claims that progressives wanted to gut Australia’s mining economy to save the trees.

Caroline Spears, the San Francisco-based director of the environmental group Climate Cabinet, said Australia offered lessons for other democracies where right-wing factions reject climate science.

“We share a lot with Australia, in climate denial and the Murdoch media,” she said, referring to the Australian-born, U.S.-naturalized Rupert Murdoch, whose media empire has demonized environmentalism.

What we do not share with Australia is the architecture of our elections. In Australia, voters are required by law to participate in elections, guaranteeing high turnout. A system of ranked-choice balloting ensures that supporters of independent and minor-party candidates have their votes reallocated if their first preference flops. That makes it a more hospitable environment for teal-style campaigns than the United States, where ballots cast for independent candidates are wasted almost by definition.

“It’s a much riskier proposition in the States,” said Ed Coper, an Australian strategist deeply involved in the teal campaigns. He said Australia helped show how to punish politicians for “treating climate as a culture-war issue.” But the independent model might be tough to transplant.

Then there is the matter of campaign finance. Climate 200 spent $13 million in Australia’s elections, to explosive effect. In America that sum would not cover the cost of one pitched Senate race. The social divisions are different, too. Many of the voters who powered Australia’s teal surge were upscale residents of cities and suburbs, left-leaning on cultural and environmental issues but less so on matters of taxes and spending. In the United States, those people are called centrist Democrats.

In September, Fay’s idea earned a skeptical reception from American environmentalists. The 36-year-old Australian left undeterred; he understood why it might sound far-fetched to people hardened in the brutal machinery of American elections. Several of the Americans wondered if he grasped how rigidly partisan our electoral system is. Besides, they had just won a generational triumph in climate policy through their usual method of supporting Democrats. The need for a wily new approach was not immediately apparent.

Yet it might be a bad reflex to shrug off a political innovation in an advanced democracy merely because its institutions do not mirror ours.

When I spoke to Fay recently, he conceded there were enormous structural distinctions between Australian and American politics. Indeed, he joined our Zoom call from a locale that underscored our divergent circumstances: I was at home in America’s frigid capital, while he was under a startling blue sky on the coast of New South Wales. He told me later he went surfing afterward.

Fay insisted the detailed asymmetries of Australian and American politics should not obscure the big, thematic similarities. The core of the teal model, Fay said, is bringing the climate fight to conservative areas showing some signs of political restlessness. It is a way of testing the loyalty of right-leaning constituencies and giving a new option to voters who care about climate but do not identify as progressives.

Of course, he said, Democrats would probably have to abandon these races for an independent to have a shot.

“If you can find two states and 20 House races in which this can work, you change the country,” Fay said. “If I was a Democratic strategist, I would be thinking: Where has potential for us in ten years’ time? And maybe now it could be competitive for an independent.”

It is a question worth engaging. If the most literal version of the teal strategy is ill-matched to American elections, is there a looser adaptation that could leave a mark?

Try this one: What if, rather than fielding a set of independents in affluent suburbs with the teal message — a blend of support for climate action, gender equality and clean government — a climate-minded American billionaire funded rural independents with a common platform of unleashing a clean energy revolution, imposing term limits on federal legislators and ending illegal immigration?

Would unaffiliated candidates with that profile do better or worse than a typical Democrat in a place like Utah or Idaho or Alaska? Who would do more to inflict political pain on an incumbent with reactionary views on climate?

The McMullin campaign last fall furnished a hint of an answer. The Utah independent lost to Lee by ten percentage points. But that was a leaping improvement on the last challenge to Lee in 2016, when the Republican beat his Democratic opponent by 41 points. In the midterms another political independent, Cara Mund, who ran for Congress in North Dakota on a message anchored in support for abortion rights, lost by a wide margin but did 10 points better than the previous Democratic nominee for the seat. There does seem to be some value in shedding a party label and brandishing a cause that confounds entrenched definitions of left and right.

That way of doing politics is alien to the United States. But with a consuming issue like the climate crisis, there is no reason to expect the cleverest political solutions will be made in America.