Yes, he rejected it a few months back because destroying the oil transports of ISIS would cause "environmental damage".
I'm not kidding.
The environmental and humanitarian cautions were Obama’s excuses, not his motivation. If a handful of innocent drivers had been blown away, and a few oil trucks blown up, why would that be worse than the result of various US raids and drone strikes?
As I responded to another poster, those are excuses, not reasons. He supports them.