Iceland is gunning to be the world’s first carbon-free economy. The country is in something of a bind, as it now has very low carbon-dioxide emissions and the Kyoto treaty on climate change gives it little room to expand its economy in a way that would increase its emissions. Already, 67 percent of Iceland’s energy comes from emissions-free geothermal heat and hydroelectric dams. During the next two decades, Iceland wants to convert its buses, cars, and fishing fleet to run off hydrogen fuel cells, which emit only heat and water. Giant companies like DaimlerChrysler and Royal Dutch/Shell, as well as the European Union as a whole, are investing in the fuel-cell projects.