Thomas Stocker Comments on the IPCC’s Polar Perspective
27 Mar 2007 - Interviews, Logistics, Arctic, Antarctic
Professor Thomas Stocker
© Thomas Stocker / Thomas Stocker
Professor Thomas Stocker is Professor of Climate and Environmental Physics and Co-Director of the Physics Institute at the University of Bern in Switzerland. His research interests include Climate System Dynamics, Climate Modelling, Past and Future Climate Change, Abrupt Climate Change, Ice Core Analysis, and Radiocarbon dating. Professor Stocker was a member of workgroup 1 for the recent report published by the Intergovernmental Panel on Climate Change (IPCC). SciencePoles recently interviewed him about the IPCC report in relation to the Polar Regions and the extent of the contribution of melting ice shelves and ice caps to sea level rise.
Professor Stocker, how has the perception of the role of the Polar Regions changed since the previous report regarding climate change, which came out in 2001? What would you say have been the most remarkable advances?
The Arctic ice cover in particular has entered the catalogue (in Chapter 10) of abrupt and non-linear changes. Furthermore, according to the projections it is now evident that the Arctic may suffer the largest temperature increases compared to other regions of the planet - in excess of 7°C according to the most drastic estimates.
To what extent have the authors of the IPCC report used the Arctic Climate Impact Assessment (ACIA) results concerning the Arctic? Would this indicate the need for a similar regional report for Antarctica?
ACIA as a report is cited, however the main body of evidence for our assessment comes from the reference literature. Clearly, the ACIA effort has galvanised science and spawned many studies that were subsequently published in the scientific literature. If not for the ACIA, these studies would otherwise not have been performed. As for an Antarctic regional report, it would be most timely as a contribution to the Fifth Assessment Report (AR5), which should be completed in 2013 or so. A major focus should be the Antarctic Peninsula and the large ice shelves.
The Summary for Policymakers (SPM) seems to give contradicting results regarding the contribution of melting Antarctic ice caps to sea level rise. This is probably due to a significant level of remaining uncertainty. Could you comment on this?
There are no contradicting results in the SPM, however the current uncertainty and lack of knowledge has been clearly laid out to policymakers. For example, we do not know whether the contributions from the melting Antarctic ice shelves will increase or decrease, or whether this phenomenon occurs independently from the rising temperature.
The most recent studies indicate a growing concern about the possible accelerated collapse of ice-shelves, if not ice caps at both poles. To what extent should we be concerned about this? Based on these latest results, do you think we should consider a sea level rise of several metres during this century a possibility?
There is simply not enough knowledge right now. There are very few papers available on this topic, which renders an assessment impossible at this point. However I am optimistic that the understanding of the dynamics and the ice-base-ocean interaction of ice shelf and the streams behind them will increase sufficiently enough to make useful statements in AR5. As you are aware, IPCC is not the proper forum for speculations, and a sea level rise of several metres during this century is merely speculation at this point.
Looking back to the report, what are the research priorities in the Polar Regions for the next assessment report?
An ACIA-type study for the Antarctic focusing on the Antarctic Peninsula and the large ice shelves would be good, plus careful monitoring of ongoing changes, both by direct and remote sensing.
By: Jean de Pomereu
