It's pretty basic- I mean what do you actually want us to tell you? It's just a green sky with what appears to be unrealistically jagged rocks and what I presume to be a cloud?
There's quite a bit you could add. Perhaps studying actual barren locations such as deserts or quarantined areas (Chernobyl) to get inspiration for real wasteland elements. Put a bit more effort into even the basic components like the sky and floor. Maybe add dust/debris particles floating around and make the ground more interesting by layering it; a foreground with smaller rocks, all the way to a distant silhouette (like what you have now) with larger formations.
As for the cloud, if that's what it is, the shading effect looks very low quality and it looks like it's been slapped on for the sake of it. Maybe check out a tutorial or two on how to create better looking clouds (I know there are loads out there).
Right now there's not a whole lot to say about it. It doesn't look like you've put much time or effort into it, so I suggest you work on the concept a bit more before asking for constructive criticism.