WCRP OSC Day 4 and 5

Day 4 seemed to be pretty much IPCC day and suddenly there was a little bit more climate science. The plenaries (with Thomas Stocker chairing) kicked off with Susan Solomon talking about the near-irreversibility of climate change, based largely on the long lifetime of CO2 even if emissions drop to zero. While it's quite an intuitive and appealing analysis - the tail of the subsequent transient temperature rise to equilibrium is largely cancelled by the slow decline of CO2 - I can't help but think that the presumed barrier at zero emissions is somewhat artificial, as even reaching zero will probably require some carbon capture technology anyway (since some people will still use fossil fuels). Konrad Steffen then talked about ice sheet loss and sea level, and it seems likely that the IPCC will significantly upgrade its predictions for sea level from its "let's ignore ice sheets" position next time around. Then Peter Stott gave a nice overview of the successes and challenges of attributing weather events to anthropogenic forcing. After the previous night's excitement I didn't have much energy for the posters. The afternoon was all about understanding climate change, and had several interesting talks. Jonathan Gregory explored the approximations underpinning the standard linear forcing/feedback analysis and showed some useful applications and limitations. The last speaker in the session, Eugenia Kalnay, mostly famous for her data assimilation and NWP work, gave a really fascinating and passionate talk about her "hobby" interest of integrating ecological-economics into earth system modelling. For me, that was one of the highlights of the week.

Friday morning had a few interesting plenary talks about policy relevance, talking about things such as meningitis in Africa (apparently there's a big climatic link, which I didn't know before) and the importance of ensuring that climate-related information is actually both useful and usable. Then there were supposed to be presentations about the upcoming IPCC report, but unfortunately the speaker on WG1 (Qin) decided to waffle about Chinese glaciers instead - which might have been interesting as a scientific presentation but was woefully off-topic at that time. The ideas behind the WG2/3 structure were better presented by Chris Field. Some questions about how they were going to avoid making mistakes this time around were basically batted back with "you're our reviewers". Then there were a succession of summaries from the plenary sessions, followed by a question and answer session which got pretty boring pretty quickly so jules and I eventually gave up and went for an early lunch, as we had another meeting to attend in the afternoon.

Finally, at 4:30pm, 12 hours before we have to get up for our flight home, we finally managed the long-overdue jog along the Cherry Creek Trail...