A major article on climate change published in the science journal NATURE concluded as follows:
"The study concludes that a moderate amount of warming, on the order of 2°C, or 3.6°F, sustained for millennia, would cause significant melting of the interior ice that lies below sea level in this region [Antarctica], raising global sea levels by 3-4 meters, or up to 13 feet."
However, there will be no oil and fossil fuels left to burn a few hundred years from now. See graph of oil reserves from The Economist, below. In addition, technology moves fast towards cleaner options, and heavy polluters like China and India cannot afford to burn coal uncontrollably because their large cities are already suffocating; more on this at The Future of Oil.
Therefore, oil based global warming over millennia is not possible!