Three months before his surprise election as the president of France, Emmanuel Macron posted a mocking video on his Facebook page. It had little to do with French domestic politics and yet the video by the liberal, ex-Socialist party minister and now partyless leader of the ‘On the Move’ movement went viral.

This video, watched by over 12 million people, was about climate change. In it, Macron gently chides US President Donald Trump over his threat to tear up the 2015 Paris agreement on climate change.

Displaying a sense of humour befitting a man who is set to become France’s youngest president at age 39, Macron calls upon American researchers, entrepreneurs and engineers working on climate change to move to France and work there, along with their European colleagues, because “here you are welcome".

“I do know how your new president now has decided to jeopardize your budget, your initiatives as he is extremely sceptical about climate change. I have no doubt about climate change and how committed we have to be regarding this issue," he says in the 9 February video.

“So I have two messages. First, for the French and European researchers: we will preserve our budgets, we will reinforce our investments, our public and private investments, in order to do more and accelerate our initiatives in order to deliver in line with COP 21. And second a message for you guys: Please come to France, you are welcome, it’s your nation. We like innovation, we want innovative people, we want people working on climate change, energy, renewables, and new technologies. France is your nation. Thanks."

What Macron does with this short provocative video is to hit several birds with a stone: First, he reaffirms French faith in the Paris climate agreement. COP (short for Conference of Parties) 21 is nothing but diplomatic jargon for the Paris agreement. It stands for the 21st conference of the parties—that is nations, numbering 195 now—that have signed up to the UN Framework Convention on Climate Change.

Second, by cleverly including “entrepreneurs" among the skilled climate change warriors he wants working in France, he is dangling a carrot that could see more green economy investments in the France he will lead. Attracting green economy investments has been the mantra of Western leaders, at least since the former British premier Tony Blair, as a counter-measure to dirty growth.

Third, by also including European scientists and researchers in his net, he immediately consolidates France’s position at the top of a continent that is the world leader in the fight against climate change, with unbeatable measures and outcomes. In other words he reinforces the need for the Mahagathbandhan—Hindi for grand alliance—to underpin the political and scientific campaign to bring global mean temperatures down, or at least keep them from rising further.

Donald Trump came out all guns firing in a campaign-style speech to mark 100 days of his presidency last month. Unable to finger Europe because it is so far ahead of the rest of us in the war against climate change, Trump trained his guns instead on emerging economies.

“Our government rushed to join international agreement where the US bears the costs and bears the burden while other countries get the benefit and pay nothing and this includes deals like the one-sided Paris Climate Accord, where the US pays billions while China, Russia and India have contributed, and will contribute, nothing," he said in the 30 April rally.

Trump promised to make a “big decision on the Paris Accord over the next two weeks and…we will see what happens." The world doesn’t yet know what he will do (and he’s known to change his mind on the fly) but he dropped some pretty broad hints: the accord, he said, fits a pattern of “global theft and plunder of American wealth at the expense of the American worker"; that full compliance will shrink the American economy by $2.5 trillion in 10 years; and “that means factories and plants closing all over our country," he added, “…(but) not with me, folks".

The problem for Trump is that the global alliance against climate change has moved too far ahead of him to step back. The majority of the world population and nations back the scientific consensus that what is causing temperatures to rise is human activity, chiefly industrialization of a certain type. Chinese President Xi Jinping, in a telephone call, congratulating Macron on 9 May, told him that China and France “should protect the achievements of global governance, including the Paris agreement", according to the Chinese foreign ministry.

Although Trump once tweeted that climate change is a Chinese conspiracy, he is not saying so now amid growing reports that his senior advisers are divided over the issue of climate change. However, he has already signed an executive order to boost the domestic coal industry and roll back climate policies set by his predecessor, Barack Obama.

It’s not just governments—finance capital (that great villain of eco warriors), too, has come out with a surprise defence of the Paris climate agreement.

On 8 March, 214 investors with more than $15 trillion of assets under management urged governments led by the US to implement the Paris accord. “As long-term institutional investors, we believe that the mitigation of climate change is essential for the safeguarding of our investments," they said in their letter addressed to the governments of the Group of Seven (G7), before a summit in Italy on 25-26 May, and to leaders of the Group of 20 who will meet in Germany in July.

Steve Waygood, chief responsible investment officer at Aviva Investors, which manages £319 billion in assets, told the Financial Times newspaper: “Any backsliding by President Trump will be a financial and economic loss for us all, not just the US economy. Unravelling (the) Paris (agreement) would also be a disaster for future generations."

In the normal course of things, a US president will have consulted his closest allies—i.e. the G7, which meets in Taormina, Italy—before announcing any major changes to an instrument as important as the Paris accord. But these are not normal times and the world will await word from the summit. A mahagathbandhan brought Macron to power, with many in the established parties transferring their votes to him, if only to keep the far right from power. It’s now time for a grand alliance to step up its global fight.

Dipankar’s Twitter handle is @Ddesarkar1