RedOrbit: Researchers based at the National Oceanography Centre, Southampton, have found that greenhouse gas concentrations similar to the present almost 400 parts per million -- were systematically associated with sea levels at least 30 feet above current levels by comparing reconstructions of atmospheric CO2 concentrations and sea level over the past 40 million years.
The study, published online in the Proceedings of the National Academy of Sciences (PNAS), determined that the "natural equilibrium"...