Why Greenland is called green land, and Iceland is called Iceland ?

Have you ever wondered why Iceland,

although only 12% of its territory is under the ice, is called the Ice land, and Greenland with 80% of ice covered territory is a green land?

 In today's episode of let me show you Iceland, 
 I'll tell you story of  Erik the Red, 
hotblooded viking who settled Greenland.