Great short talks by James Hansen, Eelco Rohling and Ken Caldeira at a press conference briefing at the American Geophysical Union Fall Meeting 2011.
The powerpoint presentation is here: AGU_paleo_final (note that the order in the PPT is different from the video).
Some highlights from the video:
James Hansen argues in the talk that “The target that has been talked about in international negotiations for 2 degrees of warming is actually a prescription for long-term disaster.” (http://www.livescience.com/17340-agu-climate-sensitivity-nasa-hansen.html), and that previous warm periods were less than two degrees Celsius above preindustrial values (image from Hansen & Sato (2011)).
Eelco Rohling argues that “in natural context, the ‘equilibrium’ sea level for current anthropogenic forcing is 25 ±3m higher than today” (see image above from the presentation by Rohling, it shows historical sea level corresponding to CO2 forcing) and that the previous interglacial was associated with very fast sea level rise rates, even above current sea level: “rates of rise above 0m of 1 to 2.5 m/century”.
Ken Caldeira talks about high climate sensitivity (“earth system sensitivity”): “Event 55 million years ago (PETM) suggests, with long-term feedbacks, 5.5 – 8 ⁰C ( 10 – 14 ⁰ F) per CO2-doubling” (image from the presentation).
Some of the papers that are discussed in the talks:
Hansen, J.E., and Mki. Sato, 2011: Paleoclimate implications for human-made climate change. In Climate Change: Inferences from Paleoclimate and Regional Aspects. A. Berger, F. Mesinger, and D. Šijači, Eds. Springer, in press.
Rohling EJ, Grant K, Hemleben Ch, Siddall M, Hoogakker BAA, Bolshaw M, Kucera M. High rates of sea-level rise during the last interglacial period. Nature Geosci 2008; 1: 38-4. ngeo.2007.28
James Hansen Director, NASA’s Goddard Institute for Space Studies, New York, New York, USA.
Eelco Rohling, Professor of Ocean and Climate Change, Southampton University, Southampton, United Kingdom.
Ken Caldeira , Senior Scientist, Department of Global Ecology Carnegie Institutution of Washington, Stanford University, Stanford, California, USA.