Copenhagen is Europe's greenest city

Copenhagen, host city of the ongoing United Nations climate summit, is the greenest major city in Europe, according to a survey published on Tuesday.

The study, presented by German industrial giant Siemens during the Copenhagen meeting, ranked 30 major European cities in eight categories, including carbon dioxide emissions, air quality and energy use.

Stockholm, Oslo, Vienna and Amsterdam were placed just behind Copenhagen at the top of the list. The least environmentally friendly cities were Kiev, Sofia, Bucharest, Belgrade and Zagreb.

Among other major capitals, Berlin ranked eighth, Paris 10th, London 11th and Rome 14th.

James Watson, managing director of the Economist Intelligence Unit, said that almost all of the 30 cities had lower CO2 emissions per capita than EU countries as a whole.

"All of the cities face formidable challenges, however. For example, renewable sources of energy currently account for only seven percent of these cities' energy supply, which is significantly under the target of 20 percent set by the EU for 2020," said Watson.

The December 7-18 climate summit in Copenhagen has brought together 193 countries to hammer out a climate deal to curb global warming and help poor nations cope with its consequences.