First off, I'm going to agree that it's long on guess work and even short on good theory :)

I didn't word my post carefully. When I said 90% I meant that there was a lot of biomass produced in the oceans, too. At 20 degrees higher there wasn't any ice, lots of water.

The reason to pitch a fit is that it's happening too fast and most organisms can't adapt if the temp goes up even 10C. Maybe even us. There is a lot of wailing and gnashing of teeth but if you REALLY listen it's about moving. People are going to have to move if the temp goes up much. And the countries that have really good production belts are really worried that the belts are going to move closer to the poles which makes less total land for growing stuff on and some places are going to have production moved outside their borders.

Ever hear of Emanuel Velikosky? He theorized that all our oil came from Venus when it bumped into us in the way back. Worlds in Collision was his epic work. Got a lot of play in the early 70s.

Which is just a way to say I have no good idea where oil comes from. I have no idea if it's still being produced. Neither does anybody else. Know.