Dear EarthTalk: I recently heard that Sweden is the greenest country in the world. Is this true and, if so, by what standards? And where does the U.S. rank? -- Raul Swain, New York, NY
It's true that Sweden came out on top in the recently released ranking of 60 countries according to sustainability by consulting firm Dual Citizen Inc. in its fourth annual Global Green Economy Index (GGEI). Norway, Costa Rica, Germany and Denmark rounded out the top five. The rankings take into account a wide range of economic indicators and datasets regarding leadership on climate change, encouragement of efficiency sectors, market facilitation and investing in green technology and sustainability, and management of ecosystems and natural capital.