The future of theatre has arrived, and it’s looking pretty nippy. Six weeks ago the Mayor of London announced a “greening London’s theatre” initiative, calling for companies to cut their CO emissions by 60 per cent by 2025. But what is the carbon footprint of your average theatre? How can it be slashed by two thirds? And is a greener panto season really going to make the slightest difference to global warming?

The touring company Cilgwyn Theatre thinks it is. It is creating the first entirely eco-friendly staging of The Faerie Queen, opening next week at the Lilian Baylis Theatre in London. All the costumes, props, puppets and sets for the show have been made from recycled, reusable resources. In their pint-sized shared studio in Tooting, South London, these renewable theatre pioneers don fingerless gloves rather than turn on the heating, while a full moon is making a fine stab at outshining their overhead low-energy bulb.

“It wasn’t a money-saving initiative,” says Becca Cox, Cilgwyn’s artistic director, “it was an ethical decision. We don’t own a building, so we were having to scrap all our sets after a run and start again from scratch. We decided to see if we could use only recycled materials instead. The results have been amazing.”

The puppeteer Iestyn Evans, 29, has found that making green theatre has changed his entire way of working. “Normally,” he says, “you read the script and come up with an idea. Then you go out and get the materials. Now, you’ve got to think, what can I get? Foam’s out, for instance – it doesn’t recycle. Once you’ve found your materials, only then can you sit down and think, ‘OK, now what can I make?’ ” In this instance, with wire from an old elephant puppet, material from a clothing collective in East London and a spot of sticky-back plastic, Evans has concocted the outline of one of three puppets that he’ll be making for Cilgwyn’s retelling of Spenser’s epic poem.

This first for Cilgwyn could soon become industry-wide standard practice. The cultural reverberations of the 2006 Stern Report on climate change proved seismic. The Arts Council created the post of arts and ecology officer at the beginning of October, currently filled by John Hartley, to help arts companies to tackle their environmental impact. Then came the mayor’s initiative, and on November 15 the world’s first climate-change Bill was passed, laying down legally-binding targets to lower UK CO emissions by two thirds by 2050.

But how much difference can tightening theatre’s green belt actually make? And what will it mean for the companies themselves?

“It’s the single biggest issue facing the industry today,” says Mhora Samuel, the director of the Theatres Trust, “for two reasons: government legislation and rising fuel bills.”

The National Theatre and the Ambassadors Theatre Group (ATG) have both signed up to the greening initiative. The National’s carbon emissions for 2006 amounted to 4,435 tonnes. According to an Environment Agency spokesman, that is not a lot: “Power stations emit about 200 million tonnes.” Nevertheless, the National isn’t shirking its challenge to cut emissions. It was built in 1972, when Sir Denys Lasdun had only grandeur and Modernism on his mind in designing the iconic South Bank edifice. But, as a result of a new deal with Philips, replacing old external fixtures with high-tech diode lighting, the National has already knocked £100,000 off its annual energy bills.

Even the ATG, many of whose 23 venues date from the 19th century, claims that it will cut energy consumption by a third purely by being more efficient. Turning off lights, taps and PCs, installing insulation and low-energy technologies are top of its greening list.

But next to the music industry’s stadium tours and the film and television industries, theatre’s a veritable green lung of an art form, surely. A recent study by the University of California discovered that the LA film and television industry ranked ahead of aerospace manufacturing as a major pollutant.

So are theatres being singled out unfairly? Ben Todd is the executive director of the Arcola Theatre in Hackney, East London, which announced plans to become the world’s first carbon-neutral theatre in July. He admits that the carbon footprint of a theatre show is relatively trivial, but he argues that it’s not so much what theatres can do to reduce emissions, “it’s what they can inspire others to achieve”.

“I did a PhD in fuel-cell technology,” he says, “and I could easily have built a carbon-neutral sewerage but nobody would notice. But if you even say you’re going to make a carbon-neutral theatre, it’s a headline. Headlines change people’s minds. And it’s only by fundamentally changing the public’s thinking on climate change that big business is going to have to follow suit.”

The Arcola plans to install solar panelling, a biomass boiler, powered by rubbish and discarded sets, and fuel-cell technology to generate and store enough power to meet its annual energy requirements. But as Mark White, the chairman of the Association of British Theatre Technicians explains: “It’s flat-out impossible for buildings such as the National or the Barbican to become self-sufficient. The technology just isn’t there. They’ve got to look at ways to cut consumption.”

Which they are doing. The Barbican’s 2006 emissions were about the same as the National’s, which, considering that it is more than twice the size, isn’t bad going. Except that it doesn’t include all the flights that Barbican personnel and visiting arts companies took in 2006. Barbara Crabb, the head of contracts and facilities, says: “We’re creating environment policies for every aspect of the Barbican, and international travel and heating are the two biggest challenges we face. The trouble is, we’re being told to cut emissions, but nobody’s telling us how.”

Klamity, the theatre company run by Finn Hanlon, 24, goes one green step further. Its next show, at Southwark Playhouse in June, will be an ethically sourced, postapocalyptic retelling of the Mad Hatter’s tea party. The designer is currently creating kinetic costumes, which transform the calories that performers emit into light cells. And all the extra electricity for the show will be produced by the power of the audience’s thighs, harnessed through cycle dynamos.

Last Saturday it hosted its first cycle-powered band night at Southwark, courtesy of a prototype dynamo borrowed from a squat in Bath, linked to three standing bikes. The drawback is that if the audience members flag, the power does too.

These are baby steps, admittedly. By one estimate, it would take the constant peddling of 15,000 Olympic-standard cyclists, weighing ten stone or more, to deliver enough energy to power the National.

Nevertheless, Hanlon is convinced that all arts organisations are going to have to “revolutionise their thinking” about energy. And Klamity and Cilgwin have concluded that a palpable aesthetic shift is just around the corner. As our carbon-emissions awareness grows, they believe our taste for energy-hungry spectacles will diminish, until big, glitzy productions such as those of Cirque du Soleil will seem distasteful, because of being needlessly wasteful.

Mark White agrees. “What we’re going to see in future are smaller venues, which are easier to heat and light, and lots more of them, so that people have to travel less. Productions are going to look very different, less bright, less real. And it simply won’t be as comfortable for audiences.”

John Hartley, from Arts Council England, concludes: “Theatre’s in a unique position to lead the way. It’s relatively independent, and historically, it has always united hugely creative and cutting-edge technical thinking. And in times of crisis, our greatest resource is imagination.”

So, theatre has got to save the world? “It hasn’t got to,” he says. “But it might.”

The Faerie Queen is at the Lilian Baylis Theatre, EC1 (0844 4124300), from Dec 11

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