Europe's greenest capital cities

It’s more important than ever for the world’s major cities to establish their ‘green’ credentials, but what exactly does that mean? 
Is it cutting down on pollution? Is it about winning awards? Or literally increasing the amount of green space? 
We’ve looked at all these factors and more, to try and establish the top 25 greenest capital cities in Europe.  

1. Copenhagen, Denmark
The 2014 winners of the European Green Capital Award also take the top spot as the greenest capital city based on the study. The Scandinavian city performs particularly well when it comes to low congestion levels and high numbers of people choosing public transport or walking and cycling for their commute.  
2. Stockholm, Sweden
In the same part of the world, Sweden’s capital, Stockholm ranks well across the board with plenty of green spaces and low congestion levels. Again, this city is one of the few winners of the European Green Capital Award, taking the title in 2010. 
3. Oslo, Norway 
This Nordic capital has low levels of air pollution and high-water quality, making it a great place to live for those looking for a green city. The city also won the European Green Capital Award in 2019. 
4. Bern, Switzerland 
Bern ranks well across many of the categories, with the highest score for quality of life and the second-highest score for green spaces. 
5. Helsinki, Finland 
As the city with the lowest annual mean air pollutants, Finland’s capital, Helsinki rounds off our top five, scoring well across the board. 

Brought to you by the energy experts. 

We looked at Europe’s capital cities taking the top 25 from the most populated countries which had an adequate level of available data.  
We ranked each city on the following criteria, giving each a normalised score out of 100 for each factor, before taking an overall average across all six factors. 
Green Spaces 
We looked at the Normalized Difference Vegetation Index, a method that processes satellite imagery to arrive at a comparable score of how much green space a city actually has.  
Air Pollutants 
The concentration of ambient PM10 air pollutants, according to the World Health Organization’s Global Ambient Air Pollution Database
Water Quality 
A score out of 100, based on survey responses regarding water quality at Numbeo
Public Transportation 
The percentage of people who walk, cycle, or catch public transportation to work as opposed to taking a car or motorbike, according to survey responses at Numbeo
CO2 Emissions 
Estimated amount of CO2 produced each year due to travelling to work/school, per passenger, measured in kilograms, according to Numbeo
Quality of Life 
Scored according to Numbeo’s Quality of Life Index, which rates cities based on climate, traffic, pollution, health, safety, cost of living, and purchasing power.