Sunday, January 22, 2012

The greenest cities in the world

Photo: Ángel Hernández Gómez
Generally speaking, we all love rankings. Despite being a superficial, simple way to map reality, rankings are useful to break the mould and fight against prejudices. Today, we will talk about a very interesting ranking drawn by the United Nations Humane Settlements Programme (UN-Habitat) in collaboration with the German multinational company Siemens: the Green City Index.
[Note for fussy readers: it is true that “German multinational” is an oxymoron, but having such companies as Siemens as sponsors of environmental studies is not very coherent either]
This survey measures eight variables for the assessment of the environmental performance of cities: CO2 emissions, sanitation, land use and types of buildings, transport, water and air quality, waste management and environmental governance. Thanks to these data, we get a list with the major leading cities in each continent, ranked from the greenest to the dirtiest. It is a shame that only in two continents (Europe and North America) the results are expressed in real numbers and figures --otherwise we could have compared cities from different continents. Moreover, the data of cities in Oceania are not available yet (the African Green City Index was published just one month ago), so we cannot check the results of Auckland and Wellington, the two largest cities of New Zealand, which usually are at the top of such rankings. Anyway, it is still interesting to enter this web site and take a look at the results published so far.
In Africa, the greenest cities are Accra (Ghana), Cape Town (South-Africa) and Casablanca (Morocco), each one located at the other end of the continent. The least green cities are Dar es Salaam (Tanzania) and Maputo (Mozambique).
However, in Europe most green cities are located in the same area, which is an easy guess: Copenhagen, Stockholm and Oslo. You can’t go wrong. And the least green cities are also as expected: Kiev, Sofia and Bucharest. Madrid ranks number 12, just after Paris and London and before Rome and Warsaw.   
In Asia, the greenest city is Singapore by far, followed by Hong Kong and Osaka. The dirtiest cities are Karachi (Pakistan), Bangalore (India) and Hanoi (Vietnam).
In Latin America, Brazil has four of the top five green cities: Curitiba, Belo Horizonte, Brasília and Rio de Janeiro. The other top five is Bogota, ranking number 3. The least green cities are Guadalajara, Lima and Buenos Aires –the latter has very poor air quality, no pun intended. 
Finally, the greenest city in the US and Canada is San Francisco and then Vancouver, one from each country. The dirtiest towns are Detroit, Saint Louis and Cleveland.


  1. UN-Habitat website with the data of African cities in relation to this index:
  2. Green City Index:
  3. An oxymoron:


Note: Only a member of this blog may post a comment.