In 2008, when much of the western world was reeling from the aftermath of the banking collapse, the US state of Utah quietly came up with a radical solution. The recession had hit hard, worsened by rapidly rising energy prices. Queues lengthened at food banks; unemployment and mortgage foreclosures rose dramatically. Money needed to be saved. The task fell to Jon Huntsman, the Republican governor. Instead of simply bringing a knife to public spending and pushing austerity measures, he surprised people with a new approach.

Back in 1970, an American management consultant called Riva Poor wrote a book advocating a revolution in work and leisure called 4 Days, 40 Hours. It caused a stir at the time, arguing that great benefits would flow from taking a longer weekend and working fewer but longer days. Then the issue went away. Quietly, though, a four-day week became a common option for public employees at city and county level. As a public administrator, Huntsman knew this, and he saw the opportunity to go further.

He realised that if swaths of public sector workers all worked a shorter week in unison, he’d be able to close public buildings on the extra day, so saving money. But something like this hadn’t been tried state-wide before. All kinds of problems might emerge, from childcare to public anger over lack of access to services. “I thought, we can study this for another six months or we can do it, and figure it out as we go,” Huntsman recalls.

At only a month’s notice, 18,000 of the state’s 25,000 workforce were put on a four-day week. Around 900 public buildings closed on Fridays, with even more partially closing. Many of the state’s vehicles were left in their garages on the extra day, travelling 3m fewer miles. Only essential safety services and a few other staff were exempt. You might expect such a quick and significant change to cause turmoil.

“It started with a one-year test period, and there were hiccups at the beginning,” says Professor Rex Facer, from Brigham Young University, an adviser on the initiative who also analysed its impact. “Some businesses complained about access to public officials on the day departments closed. But the agencies figured out the problems, the state communicated what it was doing better, and in six months complaints dropped to zero.”

Facer looked into how the public and state employees responded. Eight out of 10 employees liked the four-day week and wanted it to continue. Nearly two-thirds said it made them more productive and many said it reduced conflict at home and work. Only 3% said it made childcare harder. Workplaces across the state reported higher staff morale and lower absenteeism. There were other surprises, too. One in three among the public thought the new arrangements actually improved access to services. “The programme achieved exactly what was intended,” Facer says. “The public and businesses adapted to it. The extended opening times on the four days when employees worked were actually preferred by many. It was more convenient for them being able to contact public bodies before and after conventional working hours.”

Falling energy prices reduced the expected economies, but the change still saved the state millions. Staff wellbeing went up with the longer weekend and with shorter, easier commuting outside the normal rush hour, which benefited other commuters, too, by reducing congestion. It wasn’t the objective, but at a stroke the four-day week cut carbon emissions by 14%.

Then President Obama made Governor Huntsman his ambassador to China. In autumn 2011 the state-wide four-day week ended. Not because it had failed, but because it fell victim to a power struggle between the state legislature and the new, less committed governor’s office.

Yet in spite of the repeal, the popularity of the shorter week meant it was kept by the state’s larger cities, such as West Valley City and Provo, and was copied elsewhere, for example by the forestry department in Virginia. Far from being an evolutionary dead end for the workplace, the idea of changing the conventional five-day, 9am-5pm working week to reap a range of social, economic and environmental benefits is catching on.

Just weeks ago, Gambia announced a four-day week for public sector workers – not through economic necessity, but to allow more time for “prayer and farming”. In Ghana there are calls to follow Gambia’s example, to allow time for attending funerals on a Friday.

Yet mention shorter hours in Europe and people tend to think of the French 35-hour week, written off as a failure and largely repealed by former president Nicolas Sarkozy. Never mind that many French businesses kept their shorter week in spite of the change in the law – or that, quietly, over the last couple of decades, working less has also become the norm in the Netherlands. The Dutch seem to have found answers to all the practical problems that might come up. As in Utah, the public sector led the way in response to recession, this time in the early 1990s, by hiring new staff on 80% contracts.

Job-sharing in health and education is now standard. There are part-time bankers, surgeons and engineers. One in three Dutch men either works part-time or compresses his hours, as in Utah, introducing the term “daddy days” to the language. Many more women – three-quarters – work part-time. Polling suggests that almost all Dutch part-time workers do not want to increase their hours. The approach, backed by decent state childcare provision, allows for high levels of female employment.

But could it work in Britain, where we have the third longest working hours in Europe (behind only Austria and Greece)? The message from David Cameron and George Osborne appears to be that we can all expect to work longer and later in life, and very probably for lower pay. The state pension is being delayed until 68 for many, and if Britain renegotiates its relationship with the EU, as Cameron promises, even the current assurance of a maximum 48-hour week could disappear.

The last place you might expect a new, more progressive work culture to take root is in the bonus-fuelled City of London. But listening to 49-year-old Nick Robins, who analyses climate risks and challenges for HSBC, it seems the City could be hiding a little secret. “There’s not much discussion of it,” Robins says, “but if you want to work less, it seems to be quite open.” He turned his back on the City’s conventional long hours for a four-day week. “You may get 20% less pay but you get 50% more free time,” he says. Other City workers are doing the same, Robins says, but without drawing attention to the fact. He finds the lack of discussion peculiar. “It is a strange thing that in the UK we haven’t thought in a cultural sense about time. The debate is oddly absent, and then it comes up only to do with family – in other words, swapping one type of work for another.”

Some businesses, though, are less shy about the benefits of a shorter week. Michael Pawlyn is one of the architects who worked on the Eden Project in Cornwall, and has gone on to become a world expert on biomimicry, taking lessons from nature on how to make things better. He’ll explain how a beetle can teach you to harvest water in the desert or make fire detectors more sensitive. A big lesson from nature is the importance of fallow time: no ecosystem can be 100% productive all the time. Pawlyn gives staff at his own company “exploration days”, when people can just go away and think. “It helps you to distinguish the things that are important from the things that are merely urgent,” he says.

Jane MacCuish is a former colleague of Pawlyn’s who works for Meadowcroft Griffin, an architecture firm where part-time working is the norm. Along with the company’s directors and several of her colleagues, she works an unconventional shorter week. “I work only during school term time and the school day, from 9.30am-3pm,” she says. “I work the same hours as my children, and I am efficient and productive in the time I have. The studio benefits from experienced people who need to balance their lives re-entering work, and you can’t underestimate the value to society of having parents there after school for children.”

The apparent indispensability of key professionals, in the health sector for example, is often used as an argument against shorter weeks. But Caroline Thould, a 39-year-old radiographer, found her employer, University College London Hospital, was open to the idea. She and her husband Peter both decided to go part-time after the birth of their second child, to share childcare.

“We’d both been full-time,” Thould says, “and it was hard to lose the equivalent of a full-time salary, but we save on childcare. We still manage a holiday each year, and I think the children will benefit in the long run.” In the time they claimed back, the couple helped build gardens at their children’s nursery in Flitwick, Bedfordshire.

It’s not only well-paid professionals who can afford to work less. Kathleen Cassidy is a 26-year-old community organiser on a low income who chose to work a 25-hour week. “I didn’t have huge outgoings,” she says. “Rent, food, not much on travel. I’ve never been much of a spendthrift, never really spent on holidays, cars or things like that. It simplifies life, having less money.”

In her spare time, Cassidy has helped former prisoners with their rehabilitation, built a community garden for a housing association and been an activist with the campaign group UK Uncut. “It’s about balance and having a passion,” she says. “Also not being on a treadmill, where you just work, eat and sleep. I felt I wanted to produce things rather than consume all the time.”

These people made choices to work less and adapt their lives. They are pioneers in a country like Britain, which does little to make it easier for people to work less. Choice matters, too. Research by the New Economics Foundation shows that voluntarily working less is positive for our wellbeing, but compulsion, especially in the context of an economy not designed to support part-time work, ruins the benefit.

There are, though, now several reasons we might all want and need to adapt. A recent report from the Centre for Economic and Policy Research suggested a worldwide shift to shorter working hours could reduce carbon emissions enough to halve additional expected global warming between now and 2100.

Then there’s the fact that some people in Britain work very long hours, with often involuntary unpaid overtime. The TUC calculates that five million workers give the equivalent of a day’s worth of free overtime to their employers every week. Yet we also have high unemployment, making for a divided country burdened with related social costs.

Nick Robins, whose work is all about horizon gazing, thinks we face a long-term future of low to no growth, meaning we might all have to reconsider how we work. “I think we could have to recognise that the norm of a five-day week for everyone is not possible or desirable,” he says. Even when economists recall periods of so-called full employment in Britain, they refer to periods when women were homebound, providing the free maintenance of a mostly male paid workforce. Big changes will be needed to make shorter working weeks viable for low-income families.

Faced with systemic economic and environmental threats, we’ve been told we all have to work harder and find new technological fixes. Could it be that, instead, the best solution might be a simple, social innovation, an option we’ve had all along? If working less and better can reduce pressure on public services, create a healthier society and cut greenhouse gas emissions, is it time for national “gardening leave” for all? “I wish I’d spent more time at the office” are words few would carve on their headstones

• Andrew Simms is author of Cancel The Apocalypse: The New Path To Prosperity, published by Little Brown at £13.99 on 28 February. To order a copy for £10.99, go to theguardian.com.