Add comparison shown in Scientific American s article The Last Great Global Warming by Lee R Kump June 29 2011 Add comparison shown in Scientific American s article The Last Great Global Warming Surprising new evidence suggests the pace of the earth s most abrupt prehistoric warm up paled in comparison to what we face today The episode has lessons for our future by Lee R Kump June 29 2011 Quotation example References include The Paleocene Eocene Thermal Maximum A Perturbation of Carbon Cycle Climate and Biosphere with Implications for the Future Francesca A McInerney and Scott L Wing in Annual Review of Earth and Planetary Sciences Vol 39 pages 489 516 May 2011