This is a beautiful picture and all, but Gliese 581 c/g is a tidally locked planet. one side always faces the sun, one side faces away, and the strip in the middle is all that can support life. Under such conditions, the sky would be blood red, and due to lack of photosynthesis, plants would also lack chlorophyll, making them black and carnivorous.



Not to mention that it's twice to for times the size of Earth, so 2-4 x gravity would mean all land animals would be short and stocky.



So essentially, it would look like Hell and be... populated by... imps. o_O



...I like your way better.