Email this Photo 1 of 13 images Next 13 Top Green Cities Reykjavik, Iceland Remember the grade-school memory device "Greenland is icy and Iceland is green"? It's truer than ever thanks to progress made by Iceland and its capital city in recent years. Reykjavik has been putting hydrogen buses on its streets, and, like the rest of the country, its heat and electricity come entirely from renewable geothermal and hydropower sources and it's determined to become fossil-fuel-free by 2050. The mayor has pledged to make Reykjavik the cleanest city in Europe. Take that, Greenland. Content provided by Grist (Photo Credit: © Jeremy Woodhouse/Photodisc/Getty Images)