Oslo is the third “greenest major city in Europe” according to the first European Green City Index published by Siemens, but ranks highest in two out of eight categories. The study was conducted by The Economist Intelligence Unit and presented by Siemens during the UN Climate Change Conference in Copenhagen on 8 December 2009.

Oslo is the main location for Norwegian research and development, and many of the institutions are clustered in the area around the University of Oslo, the largest in Northern Europe.