According to the latest Environmental Performance Index, compiled biannually by Yale and Columbia University researchers, Iceland is the top performer this year. The deciding factor was the fact that nearly all of the country’s energy comes from renewable sources.

Geothermal energy being harnessed in Nesjavellir, Iceland. Photo by Páll Stefánsson.

Other European countries also scored high, including Switzerland, Sweden, Norway and Finland. Meanwhile, the world’s largest economies have moved further down the list; the US ranked 39th two years ago but is now in 61st place and China dropped from 105th to 121st place, the New York Times reports.

“Countries that take seriously the environment as a policy challenge do improve, and those that don’t deteriorate,” Daniel C. Esty, director of the Yale Center for Environmental Law and Policy, who oversees the index project, said in description of the ranking.

“Both the US and China are suffering because they’re industrial and haven’t been paying much attention to environmental policy,” Esty added.

Costa Rica is high up on the list because of actions taken to preserve rainforests and Columbia because of its efficient development of an environmentally-friendly public transport system.

The New York Times points out that the information used to evaluate the world’s top environmental performance comes from the countries themselves and could therefore be unreliable, mentioning Cuba placing ninth in that regard.

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