New Schedule Seen to Improve/Strengthen Impacts Portion of IPCC Report

Climate scientists hope to improve the most contentious section of the next report from the Intergovernmental Panel on Climate Change (IPCC) by changing how they deal with uncertain data, connect with basic science, and include data from sources that aren't peer reviewed. Meeting this week in Tsukuba, Japan, the scientists hope the changes will make their portion of the three-part 2013 IPCC report even more robust.

Speaking by phone from Japan, ecologist Chris Field, of the Carnegie Institution for Science in Palo Alto, California, says that past criticism of the panel on impacts and adaptation strategies, which he chairs, has only strengthened efforts to improve its next report. "If anything, the criticism made authors more willing to be involved," says Field. "The challenges the IPCC faced pulled out the best scientists in the field." Hundreds more scientists volunteered or were nominated for each of the three working groups than in the past, and more than 200 are participating in this week's workshop. That's fortunate for IPCC, since its workload has burgeoned.

The 2007 version of the report from Working Group II had 20 full chapters. The next one will have 30. The new chapters, reflecting growth in the science, include sections on a number of areas of impacts science like adaptation, impacts on lakes and rivers, and security.

Among the tweaks to IPCC's procedures that the scientists are learning about in the 4-day session, which wraps up tomorrow, are new guidelines for dealing with uncertainty, the use of literature not published in journals, and the confidentiality of drafts. The first two are areas in which a high-level independent review of IPCC has called for improvements.

A significant problem facing IPCC is how to make the literature reviewed in the impacts working group reflect the climate scenarios forecasted and reviewed in the first working group's report. (The information is generated by "IPCC runs" on supercomputers of different models given what amounts to identical starting conditions.) In a perfect world, the studies on impacts would reflect the possible scenarios produced by the first group. But in the past there hasn't been enough time to do impacts studies on literature new enough to be included in the IPCC report. So scientists have used future warming scenarios from literature that's older, creating a mismatch in the final IPCC report.

To lessen the problem, organizers have shifted the schedule so that the outputs of the IPCC runs from the first working group will be released with more time to spare so that the Working Group II researchers can run those climate scenarios in their impacts models. Under the new timeline, the gap between the release of Working Group I model data and the deadline for when Working Group II papers have to be submitted to journals for them to be eligible for inclusion will be stretched from 3 to 7 months. It's still "an aggressive schedule," Field admits.

"Three months is nearly impossible," says John Reilly of the Massachusetts Institute of Technology in Cambridge, who models how climate change may affect a host of environmental and economic factors like the biofuels industry. "You really have to have your models up and humming and ready for that [7-month period] to work, but most impacts models are pretty hands-on, not really automated to do that."

But Reilly says that "interesting scenarios" may exist outside of the IPCC's own framework for producing future climates and impacts. His group, for example, essentially creates its own "Working Group I" data by running a so-called integrated assessment of how, say, climate affects the growth of biofuels. The answer, in turn, could help mitigate climate change by possibly lowering overall emissions from fossil fuels.