Which city will be the first to stop emitting greenhouse gases? We have chosen the greenest cities in the world – and also the least sustainable – according to international rankings and the opinions of architects and urban planners.
These are the cities that know how to turn polluting urban agglomerations into environmentally friendly places . The key to these eco-cities is the right combination of political and economic measures, technology and education.
There are dozens of cities engaged in the race to become the greenest in the world . These are some of the most advanced eco-cities in Europe, Asia, Oceania and America.
What is a sustainable city?
- Consume the least amount of energy possible per inhabitant .
- It records minimum levels of CO2 and suspended particles in the air, little contaminated waters and low natural pollution.
- Maintains strict environmental and energy policies in construction, transportation and industry.
Copenhagen: the city of bicycles
Amsterdam is often associated with bicycles , but Copenhagen was the first to popularise this means of transport. “It is a mirror for other cities,” says José María Ezquiaga, architect and winner of the European Prize for Urban Planning. The Danish capital is one of the greenest cities on the planet, thanks in part to the high standards of energy efficiency of its buildings.
By 2050, the city has set itself the goal of becoming the first urban centre to be carbon-neutral : the energy it uses will be produced and offset by renewable systems, resulting in a net zero greenhouse gas emissions.
Another of its goals is to get 50% of its inhabitants to use the bicycle to go to work or class , and thus exceed the figure of 36% registered in 2009. In addition to the bicycle, Copenhagen has an extensive public transport network, such that its citizens live less than 350 meters from a metro, bus or train stop.
To cope with its growing population, the city has been constructing buildings on abandoned lots . “It is growing a lot from a real estate perspective, but in the right way, in port areas,” says Ezquiaga.
This is the case of Nordhavnen, a new neighbourhood under construction spread over small islands around the coastline. It follows the highest standards of energy ability and sustainability.
Similar to other Scandinavian cities, Copenhagen also uses a clean patch heating system, which covers the needs of 98% of the population. In its case, one third of this heat is generated by the incineration of waste and biomass.
Medellin: A change of face
Colombia’s second most populous city – with nearly four million people – second only to Bogotá, is managing to leave the scourge of drug trafficking behind thanks to numerous social initiatives based on sustainability . “For years, Medellín has worked intensively on social inclusion, to become a space increasingly shared by all sectors,” explains John Fredy López Pérez, professor at the Faculty of Engineering at the University of Medellín.
It is the only city in Colombia that has a metro service, integrated with public cable cars –Metrocable–, as well as buses and bicycles, and work is being done on a future tram. “They have been working for twelve years to correct inequalities, promoting the use of public transport, such as the cable cars that connect the most remote neighbourhoods with the metro, to reach the city centre,” summarises urban planner José María Ezquiaga.
A project is also underway to restore the water and landscape quality of the Medellín River , which runs from south to north. “The emergence of drug trafficking throughout the country in the 1970s created a very violent situation for this city, which resulted in deaths, terrorist attacks, kidnappings and a very pronounced insecurity until the beginning of this century,” laments engineer López Pérez.
However, this expert adds that “the last decade has meant the progressive overcoming of the stigma of drug trafficking and its consolidation as a city that has the capacity to generate innovative solutions to its problems.” As challenges, Medellín has to eradicate substandard housing , social inequalities and crime.
New Orleans: Led by Stars
The birthplace of jazz was flatten by Hurricane Katrina in 2005. Half of the population was forced to abandon what little remained of their homes, and today, ten years later, traces of the misfortune can still be seen. In 2007, in this desolate environment, the Make It Right initiative was born , led by actor Brad Pitt.
The actor travelled to one of the neighbourhoods hardest hit by the hurricane – the lower part of District 9 – two years after the disaster and, seeing that nothing had been rebuilt, he launched this project to build safe and sustainable housing in the worst-hit part of the city . Twenty-one architects designed the green homes, following principles that could be reproduced anywhere and at low cost.
The residents themselves met with Pitt and the team of architects to inform them of their needs and to help design their homes. Once the objectives were established, the fundraising
process began, and in 2008 the first keys were handed over , with the support of former President Bill Clinton and his Global Initiative.
“Make It Right builds homes, buildings and communities for people in need,” they say on their website. In addition to continuing to help residents of New Orleans, the project has expanded to Newark, New Jersey, to build an apartment building for disabled war veterans; to Kansas City, Missouri, to help a blighted community; and to the Fort Peck Reservation, Montana, where they build homes for Native American Indians.
Stockholm: outdoor life
It is striking how the people of Holm take to the streets to do sports as soon as their working day is over, regardless of whether it is cold, rainy or snowy . According to the Siemens Green City Index, 68% of the population goes to work on foot or by bicycle. And 95% live within 300 metres of a park.
Greenhouse gas emissions have been reduced by 25% since 1990, buses are powered by renewable energy and trams have been introduced as a form of transport. All these measures led to this Swedish city becoming the European Green Capital in 2010, the first to receive this award. By 2050, it has set itself the goal of achieving complete independence from fossil fuels.
It has also implemented very strict measures to reduce noise pollution , and among its great ecological achievements is the district heating system, similar to the one in Copenhagen. This is a project that began half a century ago and has managed to supply 80% of its residents. It consists of producing heat and distributing it through an urban network . It has four generating plants, in which the energy comes from biomass, waste used as fuel and residual heat.
Nantes: an example of solidarity
Situated on the banks of the Loire River, this French city is a remarkable example of solidarity. 25% of its homes are socially protected, and all residents enjoy public services such as transport , waste management and energy supplies , regardless of their income level. The services of the capital of the Loire-Atlantique department are designed in such a way as to encourage cohesion, such as communal family gardens, collective composting and heating systems that use renewable energy.
In addition, Nantes has managed to reduce urban sprawl and has preserved more than 15,000 hectares of natural and agricultural spaces . It has nearly a hundred gardens and 250 kilometres of waterways linking the city to the countryside, a way of preserving the flora and fauna that thrives in the surrounding area.
All its inhabitants live within three hundred metres of green areas and it is estimated that there are more than 100,000 trees in the city centre. For all these reasons, it became the European Green Capital in 2013. In addition, old buildings are restored and given new uses and functions. This is the case of the island located in the city.
The site was used by the port and shipyards until they were abandoned. An eco-district has been built in its place, equipped with environmentally friendly housing, gardens, leisure areas and shops. The authorities estimate that it will be able to accommodate around 20,000 people.
Freiburg im Breisgau: the cradle of ecology
Baden-Württemberg, Germany’s fourth-immense city, is one of the birthplaces of the environmental movement. Its city council advocated solar energy over nuclear energy in 1986, after the Chernobyl disaster . In 1997, it was one of the first in the world to install containers for organic waste, and today it transforms organic waste into biogas, which it uses to produce thermal and electrical energy. The city has about 420 km of cycle paths and only 423 passenger cars per chiliad population. Its goal is to turn down CO2 emissions by 40% by 2030.
Reykjavík: natural energy potential
Iceland ‘s location on the Mid-Atlantic Ridge makes it one of the most tectonically active areas in the world. Its more than two hundred volcanoes, springs and geysers are proof of this. Taking advantage of the energy potential of its nature, the island has five geothermal power plants that produce electricity and hot water to supply heating to the entire country.
The development of the district heating network began in 1930 , with the installation of a system at the Austurbaejarskoli school in the capital, Reykjavík, which used three-kilometre-long pipes to supply heat. Today, this method supplies more than 90% of Icelandic homes.
In 2011, 84% of the primary energy used in the country was generated by renewable energy plants – 66% of which was geothermal. In addition to geothermal energy, there is also hydroelectric power, which harnesses the power of the numerous waterfalls, lakes and springs that flood the country.
There is also hydrogen, because Reykjavik has a fleet of buses that run on hydrogen fuel cells, produced entirely from renewable energy. It is produced through electrolysis, which breaks down water into hydrogen and oxygen . This indigenous green energy, at very low cost, is becoming a powerful attraction for innovators and entrepreneurs from all over the world to choose to settle in the Icelandic capital as a base for their start-ups.
Reykjavik is also completely in tune with nature. So much so that you can fish for salmon and trout in the three rivers that run through it; there are lush forests within the municipality and even a 914-metre-high mountain – Mount Esja. And all of this without forgetting the thermal beach Nauthólsvík, just a few kilometres from the city centre.
Curitiba: calculated urban expansion
If there is one green city in Latin America that stands out above the rest, it is the Brazilian city of Curitiba. Located in the south of the country, it developed a general urban development plan in the 1960s that has been basal to its proper urban planning and wholesale.
The main objective was to improve the quality of life of its inhabitants, and to do so, the radial structure of urban expansion was changed to a linear one, in which transport, the road network and land use were integrated . The historic centre was also preserved, decongesting traffic, and the population was contained within its physical-territorial limits, guaranteeing the facilities of the entire urban area, which is close to two million inhabitants.
“Today there are express bus lines with elevated stations that replace the metro,” says Ezquiaga. This rapid transit bus system was a world first and forms the city’s integrated transport network , which extends to other nearby towns. Its smooth operation ensures excellent air quality. In addition, since 2009, local authorities have been conducting a study to measure CO2 emissions and determine the rate of CO2 absorbed by urban green areas.
Curitiba’s state-owned water company has extended its services and sewerage system to 1,790 households in the Vila Zumbi dos Palmares settlement, located on the banks of one of the city’s main water supply sources . This reduces water pollution and provides legal water supply to this disadvantaged community.
Bogota: green city
Located at 2,630 meters above sea level, the Colombian capital is gradually managing to leave behind its serious problems with drug trafficking and crime and is focusing its efforts on becoming the greenest Latin American city. In the last decade, it has replaced traditional buses powered by fossil fuels with a new fleet that runs on natural gas . It has also launched electric taxis, which run on internal rechargeable batteries and have a range of 250 kilometers.
Initiatives such as Mejor en bici or La ciudad verde encourage residents to use two wheels to get around and, at the same time, promote ecological awareness in the country’s main cities. Along the same lines, every Sunday morning the Ciclovía is celebrated: the main streets are closed so that a million people can go out and practice cycling and other types of physical activity safely, in a circuit of more than 121 kilometres in length.
As regards natural resources, the City Council has launched a campaign to protect and decontaminate its fourteen wetlands. In addition, local authorities have just signed an agreement that aims to improve the quality of the water in the Bogotá River.
To monitor and analyse the implementation of all these measures, the city has the Bogotá Environmental Observatory , a portal open to all citizens that follows the open data philosophy : it is possible to provide feedback on the published indicators and even contribute information or images.
Seattle: water quality
This largest city in Washington State was a pioneer in monitoring the quality of its water,” Ezquiaga recalls. Today, it has extended this control to monitoring pollution levels and aims to be carbon neutral by 2050. To this end, the City of Seattle has launched an ambitious Climate Action Plan.
“Thy transport sector is responsible for 40% of the city’s greenhouse gas emissions, but the biggest challenge it faces in reducing them is funding,” say the local administration. That is why the plan includes taxes on motor vehicles, among other measures.
The city is also aiming for a zero-waste strategy to recycle 70% of its waste by 2025. Telephone directories, which are increasingly less used, have become a target for the city to eliminate, as have plastic bags and even used carpets thrown away, which amounted to 14,000 tonnes in its landfills in 2004.
The aim is to start making them from recycled materials . In addition, the authorities are considering a controversial measure: fining residents who do not separate organic waste from the rest of the rubbish.
As for food, it is based on locally produced food, to boost the domestic economy . Making it healthy and accessible to all is another goal pursued by Seattle politicians.
Hamburg: forests and parks
It is surprising that, just a few kilometres from the industrial buildings, docks and cranes that make up its large port, there live slender cranes and other native birds. This German city has managed to integrate its industrial power with respect for the environment . For example, while the port occupies some 74 square kilometres, the city has reserved more than 200 for green areas, including the marshes of the islands of the River Elbe. 16.7% of its urban space is occupied by forests and parks.
For initiatives of this kind, the city was named the European Green Capital in 2011. The environment is a concern for citizens, authorities and also private companies, which invest around 45.8 million euros each year in measures to protect it. For example, through the Business for Resource Protection programme, for every euro invested by the local government, participating companies contribute ten euros voluntarily.
By 2020, the city wants to reduce its CO2 emissions by 40%, and by 80% by 2050. To this end, it has a fleet of buses powered by hydrogen through fuel cells. Public transport is a priority in the city , and for this reason, almost 100% of residents have stops less than 300 m from their homes.
San Francisco: pioneer in recycling among eco-cities
Almost as high as its hills is the municipal recycling rate achieved by residents of this West Coast city: 77 percent, the highest in the United States and Canada, according to the Siemens Index. In 2009, the city became the first in the country to require all residents and businesses to sort waste and compost material from regular trash.
“People feel responsible for promoting and living according to sustainable practices , and this philosophy has encouraged businesses and organizations to want to be leaders in sustainability ,” says Hana Böttger, professor of architecture at the University of San Francisco.
The city has been a pioneer in promoting green deals with the private sector, such as low-cost loans for homeowners who want to make sustainability-related improvements to their homes.
In companies with more than twenty employees, workers who travel by public transport receive financial incentives . And in larger buildings, local authorities carry out audits every five years to check energy efficiency.
With these measures, the San Francisco City Council estimates that energy consumption will be halved within two decades . “In addition, there is a general awareness of the benefits that reducing the carbon footprint can bring to our activities. For this reason, locally manufactured goods and services are highly valued,” says Böttger.
Vancouver: renewable sources
Located on the west coast of Canada, it has the longest public transport network in North America , the SkyTrain, a light rail system 68.7 kilometres long. The electricity it consumes is generated in neighbouring British Columbia, and 93% of it comes from renewable sources.
The city has set itself the goal of becoming the greenest city in the world . It has launched an ambitious plan that has already made significant progress . In 2020, it wants green jobs to double the figure of 2010 – so far, they have achieved an increase of 19%.
They also aim to reduce greenhouse gas emissions by 33% compared to 2007, and have managed to reduce this by 6%. In building construction, the goal is to be neutral in polluting emissions, and so far they have managed to reduce them by 3%. In terms of travel, they want half the population to travel on foot, by bicycle or by public transport – so far, they have managed to increase the figure by 4%.
They also aim to reduce the amount of waste going to landfills or incinerated by 50% compared to the 2008 figure – they have already achieved a 12% reduction. As for natural resources, the aim is to have planted 150,000 new trees by 2020. They also aim to increase local markets and orchards by 50% compared to 2010 levels – they are already at 30%.
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