I love the exposure and your subject, but I am not sure I like the composition. All this black space on top seems a bit useless. Not a big deal, but you might want to crop it a bit.
I really like the green to orange to black. It is slanted like Marcus said. Did you mean to do that? Suggesting the curve of the world maybe? Or you could at least say that if you don't want to cut anything off the sides.