Late last year, Rob Hopkins went to a conference. Most of the delegates were chief executive officers at local authorities, but it was not a public event. Speaking in confidence, three-quarters of these officials admitted that – despite what they say publicly – they could not foresee a return to growth in the near future.

"One said: 'If we ever get out of this recession, nothing will be as it was in the past,'" Hopkins recalls. "Another said: 'Every generation has had things better than its parents. Not any more.' But the one that stunned me said: 'No civilisation has lasted for ever. There is a very real chance of collapse.'"

Shocking stuff – shocking enough to leave many people feeling hopeless. And Hopkins has heard MPs and others in positions of power confess to similar fears in private. But the co-founder of the Transition Town movement is determined to offer courage and inspiration, and to do that he has published a short book, The Power of Just Doing Stuff, showing what people are already doing to develop a more resilient economy.

For instance, a Transition group in Brixton raised £130,000 to install the UK's first inner-city, community-owned power station, consisting of 82kW of solar panels on top of a council estate. A group in Derbyshire created a food hub that makes it economically viable to grow food in back gardens for sale, as an affordable alternative to supermarkets. And groups in Totnes, Stroud, Lewes, Brixton and Bristol launched their own local currencies. Taken on their own, these initiatives may not make a vast difference. "But when there are thousands of communities worldwide all weaving their bit in a larger tapestry," Hopkins says, "it adds up to something awe-inspiring and strong."

What he is arguing is that sweeping changes in history are made not only by "big" people doing big things but by groups of "ordinary" people doing smaller things together. And that it's a mistake to overlook those small steps.

"There is no cavalry coming to the rescue," he says. "But what happens when ordinary people decide that they are the cavalry? Between the things we can do as individuals, and the things government and business can do to respond to the challenges of our times, lies a great untapped potential. It's about what you can create with the help of the people who live in your street, your neighbourhood, your town. If enough people do it, it can lead to real impact, to real jobs and real transformation of the places we live, and beyond."

The Transition network was founded in 2005, as a response to the twin threats of climate change and peak oil. Unlike other campaign groups, the Transition network never set out to frighten people, but seemed resolutely upbeat, determined to find opportunity in what most regard with dismay.

One of the movement's most fundamental ideas was to ask what the world might look like in the future "if we get it right" – then work out backwards how to get there. Generally speaking, the Transition vision is of a move towards self-sufficiency at the local level, in food, energy and much else, but the specifics of what "getting it right" might look like were never handed down from above.

Every so often, well-meaning people give Hopkins advice. "They say, you need to set up a political party, and have politicians everywhere, and set up the bank of Transition, and a Transition power company. And I think, yeah, or what we could do is have every community build its own energy company, or bank. And that's much more powerful."

Transition is like a huge open-source research and development project, he says. "Different groups try different things, and if an idea works, it spreads."

During seven years, the movement has attracted high-profile supporters. Transition gives "great grounds for optimism," says Hugh Fearnley-Whittingstall, "on topics that are often rather doom-laden". Jonathan Dimbleby concurs: "Once upon a time, it was tempting to mock the idea of a Transition Town, but if ever there was an idea whose time has come, this is it."

A sensory garden for children in Brasilandia, Brasil

And Transition is not just a British phenomenon. There are more than 1,000 Transition initiatives in more than 40 countries. Fans include Ed Miliband and former German president Horst Köhler – an economist by profession, and former president of the IMF. Next month, Hopkins will appear at a conference with France's president and prime minister.

Filipa Leao Pimentel is involved in Transition in Portugal, but is based in Brussels and works to explain Transition to MEPs. Recently, she arranged for members of an economic and social committee to spend a day with Transition initiatives in their own countries. "I have lived in Brussels for years, and I have never seen anything like the discussion that came afterwards. There was a Greek who visited Portugal and she was touched by how we dealt with the crisis. One of the most conservative members talked about his 'journey'. Later, he said to me: 'Can you believe it, I talked about this as "my journey"?!'"

When the Transition movement started, it was driven by green politics, and its biggest critics have tended to be deep greens. One, the writer Ted Trainer, threw the movement into mild existential crisis in 2009, when he accused Transition of being merely reformist, and too "easily accommodated within consumer-capitalist society without threatening it".

Hopkins's response was, essentially, to plead guilty. "For years, in the green movement, we have held that we are right, that we have the answers … [But] many of the answers we need are to be found in people who we might, in a more judgmental moment, see as being part of the 'system', including business people, lawyers, church groups, local history groups, and thousands of ordinary people with busy lives, bills to pay and children to raise."

Today, Hopkins says he will only know that his new book has succeeded if his ideas are taken up by those kinds of people. Indeed, he wrote the book with his own sister in mind. "I hope she won't mind me saying that! She's raising kids, she's very busy. She is somebody for whom all this stuff would pass her by. Not interesting at all. But if Transition is going to get anywhere, it needs to reach people like her."

In the biggest, most successful Transition groups, every effort is made to avoid being worthy. The Tooting group's first big event was a big street celebration, a Trashcatcher's Carnival, with Arts Council funding. "In Topsham, in Devon, they asked: 'What is it that unites people in this town? Is it peak oil, or is it beer?' And they started a brewery. What are you inviting people to be part of? A group that talks about climate change? Or a historic, celebratory rethink about a place and what it does?"

The key thing is to find ways to bring people together. "In Totnes, we started to change the narrative: how do we create a culture of entrepreneurship, and support young people? And all kinds of new people came in."

At the first Local Entrepreneurs Forum, local business people gave advice to would-be entrepreneurs. But later they switched to a Community of Dragons, in which enterprises pitched to the entire community. And on the basis that "everybody is an investor", individuals pledged support in the form of time, cash, land, support, services and more.

The localisation movement has not always been good at talking about economics, Hopkins says. "If Tesco wants to open a branch in my town, they can say it will bring jobs and so on. The localisation movement never tends to do that, they just say localisation is a great idea, it's sustainable, it's good for the community. So we tried to map the local economy and put a value on it. Here in Totnes we spend £30m on food every year, of which £22m goes through two supermarkets. It's like water running through our fingers, going to banks and offshore investors. But it could be staying local. If we spent just 10% of that locally, we'd have £2.2m staying in the local economy to be spent again.

"Could a hospital that buys four tonnes of lettuce every year get that locally? If it uses energy, could it use a local energy company? We're looking at different ways of investing internally."

'Bristol Pounds' can only be spent locally, so more money stays in the city

One powerful way to prevent money leaking from a community's economy is by using local currencies. Businesses in Bristol can pay their rates in "Bristol pounds", and the city council gives staff the option to take part of their salary in B£s. The new mayor, George Ferguson, announced at his inauguration last November that he would take his entire salary in B£s, which can only be spent in Bristol. More than £180,000 has been turned into B£s, estimated to be worth £1.8m in local economic activity.

This new emphasis on economic development has galvanised the Transition Town movement, and not only in the UK. "The economic crisis helped us to gather so many people," says Pimentel. "In Portugal, we are under water. There is no money. You see your country starting to sink, and you close down, waiting for it to pass – but this is not going to pass. Transition was our framework to give people something to do. Instead of thinking, 'My god, we are sinking,' we said: 'Let's do this.' Little steps are important."

Important because they contribute to something bigger – the "larger tapestry" Hopkins talks about – but also important because it's small steps that help people recognise that they have power to make a difference. "Starting a vegetable garden in the street is small," Pimentel says. "But what is incredible is that when people learn to do that, they start to have confidence.

"The key thing is persistence. What people tell me now is, 'I thought that you were going to fail, and you did not.' They say: 'It's really true that doing little things, step by step, makes a difference.' And when they say that, I smile. I feel very proud. So even if things seem small, or you think it will not make a big difference, just persist."