Based on the Environmental Sustainability Index ­ which measures a country’s water use, biodiversity and adoption of clean energies, among other things ­ Iceland is the greenest country, with a score of 93.5/100.

The largest volcanic island is Iceland, the entirety of which was formed from volcanic eruptions from the mid-Atlantic Ridge, upon which it sits. Measuring 103,000 km² (39,768 miles²) in area, Iceland is essentially ocean floor exposed above the ocean surface.