Crowd with a silver lining: A new climate change film has found a novel way of raising cash

It was the moment that proved film maker Franny Armstrong's hard work had paid off. A contact of hers, a young professional had sent an email to her friends. Its title was simply: "Why I am kissing goodbye to my cash."

She was referring to Armstrong's latest film, The Age of Stupid, a eulogy on human excesses, specifically those that have caused global warming. Part-drama, part-documentary, the film tells the tale of a man living in the future (Pete Postlethwaite) looking back at six real-life vignettes (following the lives of a Shell employee, a French mountain guide and a windfarm developer), shot in a documentary style, focusing on those affected by climate change. It relied on "crowd funding" in which the production team's friends and family buy "shares" in the documentary to make up its £450,000 production budget. At a time when studios and broadcasters are tightening their belts, such a means of financing could be the future.

"At the moment, all the most talented film makers are working within the system," says Armstrong. "That system is controlled by the corporations, by the owners of the newspapers or Sky television. If our method works it proves we are able to fund films in a different way, and means that ultimately all films could move away from corporate control. We want to be able to speak to the public without advertising or corporate interest. That is our ultimate goal."

Armstrong's career in film making began after she heard about the McLibel trial – the 1990 libel case brought against activists Helen Steel and David Morris by McDonald's after the pair had distributed leaflets saying the fast-food restaurant encouraged litter and abused its workers. "I heard about the McLibel story and thought it was the most inspiring thing I had ever heard," says Armstrong. "I had access to the equipment, so I thought I would make a film about it to help." Worried by the threat of legal action, traditional channels would not back her, so Armstrong had to come up with cash herself, "through [her] rich boyfriend and credit cards". It was a global success, seen by 18 million people. By the time her attentions had turned to the climate change battle, she had run out of financial options.

"When I decided to make The Age of Stupid I knew it had to be completely independent. My wealthy boyfriend had long since departed. So we came up with idea of crowd funding."

The model was launched at an evening event in December 2004. "We invited friends and family and we told them to keep it under wraps because we knew it would be a controversial subject. That first night we raised £17,000 by selling 34 shares. The next day we got a camera and started filming. If you are funding a film in the traditional way you can't get going until you have all your money in a pot." Within months word spread and Armstrong's production company Spanner Films had sold 228 shares valued between £5,000 and £35,000. "The other great thing about it," she explains, "is that our investors became a brilliant support network. So we put out a message one day that we needed a country cottage for filming and the next day we had four offers." The icing on the cake is its unique distribution model. "We are doing indie screenings," she explains. "We let anyone buy the right to show the film in public after paying a licence fee, which operates on a sliding scale from multinationals to local groups. Once they have paid, they can charge the public for tickets and keep the profits. It's radical but it will work – and will pave the way for similar future projects."

'The Age of Stupid' is released on 20 March