Kyoto. Swan Theatre, Stratford-upon-Avon

How do you turn something as apparently dry and dusty as a meeting of international bureaucrats nearly thirty years ago, at which a significant amount of time was devoted to impassioned debate over the placing of commas and square brackets, into quite possibly the most riveting piece of theatre of the year?

Somehow, playwrights Joe Murphy and Joe Robertson, of the ground-breaking Good Chance theatre company, aided by directors Stephen Daldry and Justin Martin, along with a laser-focused cast, have done it.

Kyoto (even the title, sounding like it heralds a nostalgic travelogue of Old Japan, belies the electrifying urgency of what’s to come) tells the story of the diplomatic shenanigans that built up to that historic COP3 meeting, the Kyoto Agreement on Climate Change of 1997. The first half takes us through the years from the late 80s, when the issue of the planet’s health started to take hold of scientists and governments around the world. The second half focuses exclusively on the seven days in Japan’s former Capital, when, miraculously, exhaustingly, and at the last possible minute, 150 countries unanimously agreed to a legally-binding declaration on reductions in CO2 emissions. (And yes, the irony of how little impact their efforts actually had in the succeeding years is part of the evening’s horrific and spellbinding power.)

Murphy and Robertson have identified a turning point in modern politics – one where hope briefly flickered like the dying flame it turned out to be – and they make us feel like we are in the room where it happened (just as their previous masterpiece The Jungle placed audiences among the tents and tumult of Calais’ beachside refugee camps). The multi-award-winning documentaries of Norma Percy do something similar on television. In The Death of Yugoslavia and Israel and the Arabs, Percy brings together the actual decision-makers who were there at the time, and teases out of them the very human moments and memories that lay behind world-changing events.

And so it is in Kyoto. The human moments that stand out are John Prescott complaining that he hasn’t been allowed any lunch, Raul Estrada-Oyuela playing games to coax iotas of agreement from the bitterly opposed parties, a diplomat grumbling sulkily that a newly-formed group of scientists has ‘already got an acronym’.

But the magic goes deeper than these perfectly-observed moments of vulnerability. Kyoto is pure theatre, and it manipulates reality with effortless panache. Miriam Buether’s set deliberately evokes the War Room of Dr Strangelove: a vast, circular table, with the first few rows of chairs bleeding into the audience, implicating us in the process. Aideen Malone’s lighting is amongst the boldest I’ve ever seen: banks of vertically-tilted PAR cans creating columns of white light that encase the trapped diplomatic rats like patients in an operating theatre of hate. Giant screens filled with ever-changing text reflect the minute changes in wording fought over by the belligerents like a metre of French mud in 1916. At the climax, words and meaning gradually break apart in a crescendo of shouted punctuation and mixed languages. Are we in Kyoto or Babel?

The master stroke of this production, however, is that its central character and narrator, our guide to the entire affair, is actually the villain of the piece, US lawyer Don Pearlman, who fights tooth and nail to derail the process on behalf of his shadowy clients, the major US oil companies. Stephen Kunken, in his debut RSC season, is simultaneously charismatic and repulsive. He’s as slick as the oil he’s trying to exploit, and as savvy and devious as Marlowe’s Mephistopheles. The devil, of course, has all the best tunes, and that’s why making Pearlman the voice of the show is so deliciously successful. Like Salieri in Amadeus or Dick Dastardly in Wacky Races, this is his story, and watching him fail, even as he shares his anguish with us, is all part of the dirty pleasure.

The rest of the cast morph seamlessly between delegates, scientists and those murky Big Oil representatives in their dark coats. The combination of smartly-dressed manipulators and political second-guessing makes the whole thing feel like a satisfying combination of Men in Black and Yes, Prime Minister. And what could be nicer than that?

There are scenes in Kyoto that echo across the decades with hollow laughter. The opening monologue from Pearlman looks at the mess we’re in now, and tells us that, by comparison, the 90s were paradise. A brief snatch of Midsummer Night’s Dream (‘And thorough this distemperature we see The seasons alter’) lets us know that Shakespeare foresaw it all hundreds of years ago. But perhaps the most poignant comes after the climate deal has been done, and Angela Merkel shares a moment of honesty with John Prescott. ‘It felt good to be working together, you and me as Europe, leading the world in the right direction’, she said. There was a barely audible shuffle in the audience as hundreds of heads hung in unison and shame.

The one mis-step, for me, is the final scene of the play. Jenna Augen, as Pearlman’s wife Shirley, spends a good ten minutes telling us what happened to her husband in the years after Kyoto, how he died, and how she misses him. But we’re not interested in Pearlman as a human being. He is a perfect dysfunctional narrator, our cynical eyepiece on a simpler time. Being asked to care for him as a father and husband pulls the focus away from where the true sympathy of the play lies: with our ailing planet.

But this is a minor cavil on an otherwise mesmerising theatrical event. Kyoto is fast, cutting, and merciless as a Samurai sword. And it’s both hilarious and bitterly tragic. In one scene the delegates run through no fewer than 28 alternative adjectives for the word ‘discernible’ to try and find one they can all agree on. But ultimately it makes no difference. Language is fungible, and climate change is real. Then, as now, our leaders fiddle their song of compromised terminology, while before us, Earth burns.