In what order do you think the following top 10 greenest cities in the world should be ranked?

All of the cities on the Green City Times' 10 GREENEST CITIES list below exemplify a successful high use of a couple or more renewable energy sources in their energy mix. All have robust low emission and clean sustainable public transit systems. All prioritize green urban spaces and several also maintain vibrant urban forestry.

The cities on the below list have unique solutions for incorporating energy efficiency in existing buildings, new construction, mass transit, and across other energy-intensive sectors of the city's economy. These cities pursue decarbonization and environmental conservation on a local level with legislated climate action measures; as well as by utilizing, harnessing, and/ or conserving, local natural resources to significantly lower the city's carbon footprint.

Each of GCT's greenest cities has implemented its own unique set of clean energy technological solutions based on the sustainable resources available locally. Each of these technological solutions represents a unique pathway to achieve carbon neutrality in the city. The most efficient, widely available sustainable technological solutions today globally are solar + batteries and wind + batteries (or solar and/or wind with some other form of energy storage besides batteries); as well as electric vehicles.

The most efficient path for a city to develop sustainable mass transit is with electric vehicles. Many of the cities on the below list have invested substantially in public mass transit. When a city can't (or doesn't) electrify transportation completely, it becomes necessary to invest in these fuel types - biofuel blends, LNG, CNG, and/ or SNG made from biogas and/ or natural gas.

GCT's greenest cities exemplify sustainable urban planning; and have invested in developing innovative, extensive renewable energy and energy efficiency technologies, green building, green public spaces, and sustainable public transit. Additionally, these cities are implementing bold greenhouse gas emission reduction and climate mitigation strategies, public policies, and legislated mandates.

The green cities listed below meet or exceed targets set by their home countries at the Paris Climate Accord - in terms of achieving goals for climate mitigation policies and implementation of those targets with sustainable climate measures.

The TOP 10 Greenest Cities in the World:

1. Reykjavik, Iceland  
2. Vaxjo, Sweden
3. Copenhagen, Denmark
4. Freiburg, Germany
5. Oslo, Norway
6. Vancouver, Canada 
   
7. London, UK
8. Curitiba, Brazil
9. Portland, Oregon, US
10. San Diego, California, US
    

Honorable mentions for the world's greenest city:

Paris, France, Austin, Texas, New York City, New York

These cities all incorporate some of the 10+ ways to:

Stabilize Greenhouse Gas Emissions

Please also see:

World Cities’ Initiatives to Fight Climate Change

More on:

A Canadian city that is striving to be "the greenest city on earth", consistently ranking as one of the most livable cities on the planet...

A European city that averages between 2-5 inches of rainfall each month, has rain year-round and temperatures between 30-50° F for at least half of the year, however, is still considered Europe's "solar city".

An American green city that leads the nation in recycling, and features over 92,000 acres of green spaces...

The city whose metropolitan population is among the largest in the world, yet still maintains almost 40% of its area as either green space or water (a sustainable metropolis).

For comprehensive details on international climate action policies, please see>>> 

The Global Fight Against Climate Change; NDCs and Net Zero Targets Worldwide

Creating a sustainable city involves creating environmentally-focused measures, such as renewable energy and energy efficiency mandates; and the successful implementation of clean energy technologies. Public policies which support expanded investments in environmental conservation, green spaces/ urban forestry, sustainable mass transit, as well as energy efficient infrastructure for clean mass transit and green buildings; are also hallmarks of a sustainable city.

These sustainable measures can be successfully implemented (over the next 2 decades), and then the global focus must shift to deep decarbonization of all fossil fuel-intensive sectors of the global economy; on the path to global net zero emissions by 2050. After a shift to net zero emissions has seen substantial progress over the next decade in terms of energy generation, transportation, and buildings; the focus must shift to the hardest to decarbonize sectors.

Net zero by 2050 is needed to keep global warming well under 2°C by the end of the century. In order to stay below 2°C, there needs to be carbon neutrality on a worldwide level in every sector. That can be accomplished with zero and low carbon emissions technologies and electrification for energy generation, transportation, and buildings.

There also needs to be progress made on the hard-to-decarbonize sectors (industry/ manufacturing {steel, concrete, petrochemicals, etc...}, agriculture {land-use as well as food & water production}, and shipping/ long-haul trucking/aviation). In addition to successfully accomplishing decarbonization, there needs to be a global effort to sequester carbon from the atmosphere (through planting trees, carbon capture) in order for net zero goals to be realized.

To make global climate sustainable, even after decarbonization is achieved, there must be substantial investment in carbon sequestration/ carbon removal technologies and measures (stop deforestation, reforestation, sustainable agriculture, carbon farming, carbon capture, reduction of waste/ waste management, using waste to create energy as with biomass and anaerobic digestion). 

Electrification and optimal energy efficiency technologies for transportation and buildings; using renewable energy generated from the most sustainable energy sources, are also ideal solutions. However, in practical measures, most cities in the world can not and/ or do not implement only these ideal sustainable solutions.

In order to get to net zero GHGs globally, public policy worldwide must prioritize solutions that every city worldwide can invest in. Research and development of potential future clean energy technologies is also important. In addition to carbon capture (carbon capture & storage - CCS), promising future clean energy technologies include hydrogen and advanced nuclear.

Readily available sustainable solutions include carbon net neutral and low carbon energy generation sources such as solar, wind, hydroelectricity, and biomass. In the future, a low carbon solution will be natural gas combined-cycle gas turbines (CCGT) with CCS.

Other important clean energy investment priorities include advanced batteries, other energy storage solutions, and electric vehicles.

Additional sustainable priorities include low carbon transportation fuels such as biofuels, as well as other sustainable hybrid transit options such as biofuels + electricity. Low carbon transportation fuel options also include liquid, synthetic, or compressed natural gas (LNG, SNG, or CNG). 

Biofuels, ammonia, hydrogen, and electricity-produced synthetic hydrocarbon fuels (electrofuels or e-fuels) are the future of low carbon transportation fuels. Hydrogen and e-fuels created with renewable energy and carbon capture are potential future carbon net-neutral transportation fuels.

Serious climate policy for some cities must also consider investment in zero carbon emission or low carbon energy generation such as advanced nuclear power and CCGT + CCS, to augment renewable energy; when clean and renewable energy sources aren't available to provide constant energy generation. Thus, clean energy and sustainable pathways for cities potentially involve a variety of solutions. Where expedient and feasible, the green cities listed here have made progress on some or most of these sustainable energy pathways.  

Please take your time to browse Green City Times' articles on the world's most sustainable cities, our information on types of renewable energy (solar, wind, geothermal, hydroelectricity, and biomass), energy efficiency, energy storage, green urban planning, green building, and other trends in sustainability. 

Try the following links to some of Green City Times' most-read articles:

• renewable energy in mass transportation
  • 10 Countries Promoting EVs
• renewable energy storage
  • Next-Gen Batteries
• renewable energy: solar and solar thermal (PV and CSP)
  • The Rise of Solar
• renewable energy: wind (and offshore wind farms)
  • Block Island Wind Farm
• renewable energy: geothermal (and heat pumps)
• renewable energy: hydroelectricity (dams, tides and waves)
• renewable energy: biomass and biofuel
• improving energy efficiency
• carbon pricing
• green building