In the rolling hills of northern Portugal, where castles are almost as common as churches, the city of 骋耻颈尘补谤茫别蝉 is undertaking an ambitious experiment that could influence the world. With a zeal reminiscent of the city鈥檚 12th-century battle for independence, when the city鈥檚 Portuguese nobility fought off Spanish invaders to gain independence and establish the new nation鈥檚 first capital, elected officials have joined forces with sustainability scientists to transform the region once again.
At a time when many of us feel like helpless bystanders as environmental crises escalate around us, 骋耻颈尘补谤茫别蝉鈥檚 green transition is showing how it is possible to live within the planet鈥檚 essential limits 鈥� while ensuring a comfortable quality of life for everyone. 鈥淪ocial justice and the principle of leaving no one behind are truly central to our approach,鈥� says biologist who heads the Landscape Laboratory, a research and education facility created to help drive these sweeping changes in the city.
Advertisement
These might sound like utopian aspirations, but behind 骋耻颈尘补谤茫别蝉鈥檚 plans are solid calculations that, against common wisdom, suggest it is possible for the entire global population to tread the tightrope between our well-being and that of Earth 鈥� and that, in fact, the two are intertwined. But achieving that vision will require seismic shifts in economies and the way many people view luxuries versus necessities. Can this be achieved without limiting personal freedoms 鈥� and who ultimately gets to decide how much is enough to live well?
The idea that there is a 聽that humanity must find a way to live within was first described in a landmark 2009 paper by Earth system scientist at the University of Potsdam in Germany and his colleagues. They identified nine planetary boundaries 鈥� limits on phenomena such as climate change, ocean acidification and land-system change 鈥� that, if breached, will knock us out of the stable conditions that have allowed humanity to thrive for 12,000 years.
Humanity has now crossed seven of these boundaries, largely because of what we consume and how quickly we consume it (see chart below). Total domestic water use, for instance, has 鈥� a faster rate than in agriculture or industry. The overall extraction of natural resources and .
Part of this increasing consumption is vital for lifting lower-income nations 鈥� and poorer communities in wealthier countries 鈥� out of poverty. But this growth isn鈥檛 happening where it is required to achieve this. In a 2025 study, sustainability scientist at the University of Lausanne in Switzerland and his colleagues around the world. The team divided countries into those that have enough energy and resources to provide 鈥� a basic floor for well-being based on access to needs like nutrition and housing, plus a buffer to address inequality 鈥� and those that have more than enough. High-income countries already consume far more resources than low-income nations, as you might expect. But worryingly, the team found that this trend is escalating: the growth rate of consumption was four times higher in countries with surplus consumption. If these trends continue, decent living standards won鈥檛 be fully achieved in lower-income countries until the end of the century, and all the while, environmental pressures from overconsumption will intensify. 鈥淲e risk breaking the planet,鈥� says Millward-Hopkins.
Facing these material realities, in recent years, sustainability scientists have widened their lens to include principles of fairness and sufficiency. The idea is that, above a certain level 鈥� when essential needs are met and you have enough to live comfortably 鈥� , leading to what Millward-Hopkins calls 鈥渦seless overconsumption鈥�. So, by setting a reasonable ceiling on consumption, the hope is that we can collectively walk along a 鈥渃onsumption corridor鈥� that ensures a basic quality of life for everyone while keeping within the planet鈥檚 boundaries.
Living within planetary limits
Within Europe, led by a green-minded mayor, has become a leading light on this path. 鈥淲e are trying to design a city with a better quality of life, where people can live well,鈥� says Ribeiro. A decade ago, sustainability scientist at the University of Aveiro, Portugal, and her colleagues conducted a pivotal analysis of 骋耻颈尘补谤茫别蝉鈥檚 ecological footprint. The assessment found that if everyone in the world lived like the city鈥檚 residents, we would . This is significantly more than the average global consumption of 1.7 Earths. The results left city leaders determined to become a 鈥� an official designation created by sustainability consultancy Bioregional and the World Wildlife Fund 鈥� by 2050. Since then, the council has baked sufficiency and sustainability into all its decision-making. 鈥淭hey really have an impressive capacity to change,鈥� says Pires.
The council is investing millions of euros in efforts to reduce the city鈥檚 resource use. Some changes are simple: recycling-collection trucks adorned with the words 鈥渞ecycling saves money鈥� trundle down the cobblestone streets, a nod to the council鈥檚 鈥減ay-as-you-throw鈥� waste collection system, which charges residents per kilogram of refuse. And regular repair fairs encourage people to extend the life of electronics and other goods rather than throwing them away. 骋耻颈尘补谤茫别蝉 now has a waste circularity index 鈥� a measure of how effectively an economy reuses, recycles and recovers materials 鈥� that is 2.5 times the average for Portugal.
Beyond that, more fundamental changes are under way to squeeze the city鈥檚 economy into a consumption corridor. 骋耻颈尘补谤茫别蝉 is also developing a circular economy 鈥� an economic model designed to continually reuse resources 鈥� off the back of its historic textile industry, which dates back to the Middle Ages but has declined in recent decades due to overseas competition. Companies like RDD Textiles and Zouri shoes are reforming the industry into a greener mould by using recycled materials and natural dyes to produce quality products that some consumers are willing to pay more for. Each year, more than 20 tonnes of textiles are recovered across the city through this approach.
骋耻颈尘补谤茫别蝉鈥檚 is housed in a remnant of this same industry: an old textile and cutlery factory beside a now partially restored stream. Iberian chub, northern straight-mouth nase and other native fish now ply its clear waters. Founded by the city in 2014, the laboratory 鈥� in collaboration with the University of Minho and the University of Tr谩s-os-Montes e Alto Douro 鈥� conducts research that seeks to improve quality of life for residents while reducing the city鈥檚 environmental footprint. For instance, the laboratory, alongside the city and local industries, has already restored some 95 hectares of green space since 2012. The vast lawn surrounding 骋耻颈尘补谤茫别蝉 Castle, built in the 10th century to defend a monastery from the Normans and Moors, is now a rain-fed meadow, and a network of greenways connects far-flung parts of the city.
Aside from the innate health benefits of having nature on your doorstep 鈥� and the value of creating habitat for wildlife 鈥� these changes are also designed to curb consumption. A 2020 study, led by environmental psychologist Yannick Joye at Vilnius University in Lithuania, found that when participants鈥� attention was directed towards the natural elements of their environment, they . Cooling urban heat islands through ecological restoration directly reduces the need for energy-sapping air conditioning, too, while greenways encourage walking and cycling, which, in turn, drive local, circular economies.
Crucially, these nature-based strategies also offer protection from extreme heatwaves and floods, which are becoming more intense and frequent in the city due to climate change. Floodwater retention basins, which combine wetlands and meadows with retaining walls, were constructed in the city a few years ago. In January, a series of heavy storms hit Portugal, with floods killing at least 16 people and forcing thousands to evacuate their homes, but in 骋耻颈尘补谤茫别蝉, the basins held the water back.
Yet the scale and speed with which changes must be made to rein in our planetary overshoot can lead to pushback from local communities. To mitigate that, the laboratory solicits the community鈥檚 help, offering them autonomy over what actions to take. A recent call for project and activity ideas garnered 200 suggestions, 150 of which are now being implemented, says Ribeiro, such as new trails and outdoor dance performances. Environmental awareness is also at the core of the laboratory鈥檚 work, he says, inspiring 鈥済reen brigades鈥� of citizen volunteers who organise clean-ups, plant trees and conduct biodiversity surveys.
During Green Week in June, held in a shady square in the city centre, Ribeiro remembers taking in the scene 鈥� seeing thousands of residents, from grandmothers to toddlers, creating nature-inspired art and learning about how ecological restoration makes the city safer 鈥� and thinking about the sense of community pride that has coalesced around 骋耻颈尘补谤茫别蝉鈥檚 green transition. 鈥淚t鈥檚 very important to improve that sense of belonging, the sense of identity,鈥� he says. 鈥淚t鈥檚 a different approach to changing some mindsets.鈥�
Tipping points
Earth system scientist at the University of Exeter, UK, describes shifts like these as social : when changes in attitudes and behaviours trigger a much larger, often rapid and self-sustaining change across a society or system.
When it comes to creating a ceiling on consumption, one vital shift in a society鈥檚 attitudes is what it considers to be . The efforts under way in 骋耻颈尘补谤茫别蝉 suggest that some of these shifts can be achieved organically rather than through coercive policies. 鈥淲e don鈥檛 need too much food in our freezer or too much money in our pockets, and we don鈥檛 need to have 10 cars,鈥� says Sandra Freitas, a 骋耻颈尘补谤茫别蝉 native who runs a vegetarian caf茅 in the city. Freitas says she has noticed her community take greater pride in the city over the years. 鈥淓very year, we try to do better and better.鈥�
Yet evidence suggests that good intentions may only get us so far. Even holding green values seems to make little difference to your ecological footprint if you have a lot of money. One recent study found that, surprisingly, among the wealthiest 30 per cent of people, those who cared most about the environment had an even larger footprint than their peers.
Millward-Hopkins says that extreme wealth insulates people from economic pressures that might change their behaviour. He recalls witnessing this firsthand while on a cycling trip shortly after Russia invaded Ukraine and fuel prices skyrocketed. 鈥淚 was passed by a convoy of supercars, each driven by a single middle-aged guy,鈥� he says. 鈥淭he fuel consumption of people that rich has pretty much zero elasticity, by which I mean, unlike poor people, when fuel prices rise, their consumption is unaffected.鈥�
Still, for middling levels of wealth, Millward-Hopkins argues that any sense of loss brought about by limits to material consumption could easily be salved. 鈥淎ny reductions in consumption that are required by regular people in Europe or North America could be more than compensated for by providing things that really improve people鈥檚 lives: universal healthcare and education; healthy, affordable food; fulfilling work; and secure housing without the threat of eviction or mortgage spikes,鈥� he says. 鈥淎ll of these things can be provided to all without exceeding ecological limits, if we can direct our labour towards things that matter, not just what鈥檚 profitable.鈥�
That might sound like idealistic speculation, but recent calculations demonstrate how, in principle, we can all live well within Earth鈥檚 limits. In June, the World Inequality Lab published its , which argues that by embracing sufficiency and reshaping our economies towards the real sources of human well-being, we can avoid climate breakdown (see chart below).
The centrepiece of the report is a global wealth tax on billionaires that would help fund the transition to greener forms of energy and a dramatic increase in spending on education and healthcare, . 鈥淭he climate crisis and inequality are very much intertwined,鈥� says , environmental coordinator at the World Inequality Lab. 鈥淲e think that it鈥檚 necessary to make those pay who caused the climate crisis, which are the global rich.鈥�
The Global Justice Report also calls for fewer working hours and dietary changes to reduce consumption. Despite these major adjustments, the report calculates that the average per capita income across all countries could be increased to around 鈧�5000 a month by the end of the century. Mohren acknowledges the report is somewhat utopian 鈥� more of a vision than a prescription. 鈥淭he idea was really to provide a new story about a future that could be possible,鈥� she says.
骋耻颈尘补谤茫别蝉鈥檚 own journey towards living within planetary boundaries has also been held back, to at least some degree, by affluence. The city is among the wealthiest in Portugal, and despite the new leafy trails and electric bus fleet, many residents still opt to drive, even amid high fuel prices. It is simply easier for many people to get behind the wheel. 鈥淭he real challenge is changing behaviours,鈥� says Ribeiro.
Still, over the past decade, the city has made impressive changes to its levels of consumption. Against global trends, since 2018, 骋耻颈尘补谤茫别蝉 has reduced the average amount of waste generated per person by 18 per cent. Cash-incentivised recycling and waste reduction systems, as well as biowaste collection, have recently been rolled out to most households in the city. The council has also turned Bairro C, a city neighbourhood and UNESCO World Heritage Site, into a testing ground for zero-carbon policies and technologies that create economic opportunities.
In recognition of this progress, 骋耻颈尘补谤茫别蝉 was awarded the title of by the European Union. Officials from cities in Belgium, France, Italy and Spain have visited to learn from the city鈥檚 green transition over the past decade, and the Landscape Laboratory has been fielding its expertise to policy-makers in Brazil and beyond.
Regardless of which way the political winds blow, sustainability and sufficiency now seem as immutable as the city鈥檚 medieval stone walls and Roman bridges. A new mayor was sworn in last year, but the change in leadership is unlikely to affect the city鈥檚 green trajectory. He has thrown his support behind the work and the previous administration codified the city鈥檚 sustainability commitments into law, cementing 骋耻颈尘补谤茫别蝉鈥檚 green future. 鈥淚t鈥檚 almost impossible for a new mayor to come and destroy that,鈥� says Pires.
