Until the late 19th century, sod or turf roofs were the most common type of roof on rural log homes in Scandinavia. These roofs date back to before the Viking and Middle Ages.
The benefits of sod roofs are many. According to the EPA, green roofs insulate, filter pollution, reduce storm water run-off, and naturally cool the air, reducing what’s known as the “heat island effect.” [source]
They sound great but is it going to work?" READ MORE from Scientific blogging...
Interestingly, white roofs are more "green" than green roofs. "White roofs are more reflective than green roofs, reflecting roughly three times more sunlight back into the atmosphere and therefore absorbing less sunlight at earth's surface. By absorbing less sunlight than either green or black roofs, white roofs offset a portion of the warming effect from greenhouse gas emissions." READ MORE