It is not unusual for governments to focus on a big event after a period of crisis. In 1951, the Festival of Britain was meant to rejuvenate the country after years of post-war austerity and rationing. The 2012 London Olympics, presided over by Mayor Boris Johnson, supposedly announced the UK’s recovery from recession with a £27 million opening ceremony.

But games are intended to be boosterish. A 12-day summit on the environment is not an obvious crowd pleaser. Yet this government is determined to turn COP26, the United Nations Climate Change Conference scheduled to be held in Glasgow in the first two weeks of November, into a great event to put Britain on the map. There had long been talk in government circles of a ‘Festival of Brexit’ to heal the wounds of the referendum campaign — but now the Prime Minister sees environmentalism as the great unifier.

In government, comparisons are already being made with 2012. The word in Whitehall is that the event will be ‘bigger than the Olympics’. The original plan was to invite 30,000 delegates, making it the largest summit Britain has ever hosted. Thanks to Covid-19, those plans are now all in flux. But the government still regards COP26 as a significant moment. With one giant eco-jamboree, it’s thought, the country can leave behind the miseries of the pandemic, set aside the agonies of our divorce from the EU, and even shore up the Union. The idea is that Britain can use COP26 to turn itself, once more, into a global force with great PR.

Johnson is itching to put Covid behind him. He might not have to wait much longer. Vaccines are rolling out fast, the vast majority of pensioners now have antibodies and the virus is in retreat. In Downing Street, when the mood is dour, attention gravitates towards COP26: the bright green star on the government’s uncertain horizon. It’s the subject which animates the Prime Minister most these days.

Aides are brainstorming ways to encourage a green frenzy. Discussions over the right choice of cuddly mascot for the occasion are under way — something endangered, perhaps, but not too exotic. To bolster patriotic pride, Union flags could be projected on to Glasgow’s landmarks, which will no doubt delight Nicola Sturgeon. There are whispers of an Olympic-style low-carbon torch procession across the country in the build-up. The pièce de résistance of the summit could be a David Attenborough cameo.

Johnson’s new chief of staff is Dan Rosenfield. He led the Treasury team which came up with the budget for the 2012 Olympics. In meetings, Rosenfield keeps suggesting that Coldplay’s Chris Martin should be involved (the pair are contemporaries from their University College London days). ‘People have got quite carried away,’ says one figure privy to the plans.

But not everyone is enthusiastic about COP26. Some civil servants are worried about the tone being wrong and are trying to dial down expectations. Others fret that rather than boost the Union, a Boris-centric show in Glasgow could have the opposite effect. ‘Security will be needed,’ says one aide on the potential for Scottish nationalist protests. That COP26 is being held at all is considered, by some, an odd decision. Other recent summits have taken place over Zoom. Why should a climate change summit be the event that has people climbing back into their jets?

Greta Thunberg is already a ‘no’. The teen eco warrior has taken umbrage at what she regards as vaccine nationalism and says she worries that poorer countries will struggle to take part, because many of their citizens will still be unvaccinated by the time the summit arrives.

In Downing Street, however, all COP systems are still go. It’s thought that diplomatic negotiations run more smoothly if they take place with everyone in the same room. And this is, after all, meant to be the year when Britain positions itself as a global leader. There’s also the G7 in Cornwall in June, where net zero targets will be high up the agenda.

Environmentalism then isn’t just part of Johnson’s ‘global Britain’ agenda; it is the centrepiece. The recent integrated review of defence and foreign policy named ‘tackling climate change and biodiversity loss’ as the UK’s ‘number one international priority’.

It’s hoped that, by boosting his green bona fides, Johnson can also win over Joe Biden, who still regards Brexit Britain as somewhat related to Donald Trump’s populism. Alok Sharma — the minister in charge of summit preparations — is in close contact with John Kerry, United States Special Presidential Envoy for Climate.

America is also eager to greenwash its reputation on the world stage: just hours after becoming president, Biden restored the US to the Paris agreement, which aims to stop global temperatures from rising more than 2°C above pre-industrial levels. The UK team has set itself an even more ambitious target, closer to 1.5°C. The UK also hopes to take credit for bringing China’s President Xi Jinping, India’s Prime Minister Narendra Modi and Biden together to save the planet. If a deal can be done at COP26, the government feels Brexit Britain can present itself as a world powerbroker.

But will it work? Can Johnson present himself as a born-again climate warrior, winning back Remainers with a cuddlier Conservatism intended to invoke his happier mayoral days? He hasn’t always been such a keen environmentalist. When editor of this magazine, he published covers attacking ‘big green bullies’. He never fully aligned himself with David Cameron’s ‘vote blue, go green’ message. But now his aides say it is the subject he is most enthusiastic about.

His new worldview is put down to a number of factors. His fiancée Carrie Symonds is an environmental campaigner and a key influence on his thinking. His father Stanley, too, has called on the PM to prioritise a relationship with China for the sake of the environment and reaching a COP26 agreement. That has landed badly with the China hawks in the party. ‘Is a climate summit really worth so debasing ourselves, just to please China?’ asks one.

The real force driving Johnson could be political self-interest. Done right, it’s argued, COP26 could give the Tories a boost as they look towards a fifth term. The Tories won a majority of 80 on a pro-Brexit, high-spend strategy in the 2019 election, breaking Labour’s red wall. But with the forces of Vote Leave now ousted, the PM’s new allies argue that the Tory coalition must widen once again if the party is to win another term.

With Brexit done, climate change could offer a way to win over metropolitan voters — from those scarred by Brexit to Labour swing voters. ‘If you can crack that nut through support for human rights and climate change, you access a huge new swathe of voters who are hard to reach,’ says one insider.

But can that be done while keeping the red-wall supporters sweet? The government’s idea is to push an environmental agenda that doesn’t cost the earth for working-class voters. Johnson recently declared in an interview with the Sun that there will be no taxes on meat or carbon on his watch. This may come as a surprise to Treasury officials, who calculated that the cost of the ‘net zero’ target — set by Theresa May — was about £1,000 billion. The Prime Minister hopes new inventions will make energy cheaper and cleaner than these figures imagine.

Which takes us to the reality of green politics. Thunberg’s absence at COP26 won’t be met with tears. Her environmentalism is categorised as the more radical ‘dark green’ shade, which regards any economic growth as the enemy. Johnson, by contrast, considers himself a techno-green. He believes that new technology and industry will do much of the heavy lifting; that the trend of happy surprises — the collapse in the cost of wind power, the revolution in electric cars — will continue. Technology has already helped push Britain’s carbon emissions to levels last seen in 1888.

What’s hard to grasp now is the sincerity of the Tory converts. The promise of green jobs and ‘build back greener’ animates ambitious Tory MPs. If you want to get ahead in government, go green. It might even help in the reshuffle. The Conservative Home website reports that Tory MPs frequently pitch articles under their names about the importance of saving the planet. Right-leaning newspapers are also on board: the Express and Sun are among those launching green campaigns. Who could oppose a cleaner, greener future?

Almost nobody wants to ask the harder questions. Are ministers being upfront about the trade-off? Might the path to ‘net zero’ by 2050 mean a war on gas boilers in the form of mandatory and hugely expensive house renovations? One recent parliamentary report said the government’s price tag of between £35 billion and £65 billion is a massive underestimate — with almost 20 million UK properties needing energy efficiency upgrades that can cost, on average, £18,000.

Ministers are quick to deny that their red wall voters are less enthusiastic about their green schemes. They point to widespread support for protecting the planet. But general enthusiasm for environmentalism quickly dampens when it comes down to specifics. A YouGov poll last month found barely a third of those surveyed support the government’s decision to ban gas boilers in new homes from 2030.

The key to keeping everyone happy about ‘net zero’, it seems, is to not go into detail about the costs. A recent focus group in Walsall found a lot of concern over the idea that electric cars could soon be the only ones on offer, if the sale of new petrol and diesel cars is banned by 2030. Some MPs are also beginning to baulk at what they and their constituents see as metropolitan eco-snobbery. The recent government decision to block plans for a coal mine prompted local anger. Mark Jenkinson, the MP for Workington, described it as ‘a capitulation to the climate alarmists’.

For now, Jenkinson’s is a lonely voice. Who wants to spoil the upcoming COP party by asking who foots the bill?