[AlanSE]

The atmosphere can absorb it, but many ecosystems (the important ones for people) cannot survive the resulting changes in climate.

[bryanlarsen]

Of course.

I tried adding a similar caveat to my message, but my feeble attempts muddied my simple message. Even your caveat is slightly over-simplified because there's a significant time component: most ecosystems would probably be OK if the oil was burned over a few million years rather than a few decades.