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by Bob Henson

Even before the dust settles on the exhaustive fourth assessment of the Intergovernmental Panel on Climate Change, some participants are already pondering how the next one might play out. Given the huge investments of time that assessments require, how can scientists make sure that these critical reports are being produced in the best possible way?

The National Academies provides a few tips in a report issued in February, Analysis of Global Change Assessments: Lessons Learned. The study committee was led by Guy Brasseur, director of NCAR’s Earth and Sun Systems Laboratory. Also on the committee was Patricia Romero Lankao, deputy director of NCAR’s Institute for the Study of Society and Environment. The two were joined by scientists from a number of UCAR universities, private industry, and nongovernmental organizations.

“We invited scholars who were experts in assessment processes, as well as scientists who have led assessments themselves,” says Brasseur. The motive for the study was to advise the U.S. Climate Change Science Program (CCSP) on how to improve the ways in which American climate assessments are produced.

Although the IPCC is the largest and most influential mechanism of its type, it wasn’t the first. The jarring discovery of the Antarctic ozone hole in the mid-1980s led to a series of stratospheric ozone assessments conducted by the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP). These ozone assessments have involved scientists from around the world and provided guidance to policymakers. Less than five years after the ozone hole was found, the Montreal Protocol was in place, controlling the human-produced chemicals that jeopardized stratospheric ozone. It was this success, the report observes, that led to the IPCC model as well as to subsequent assessments in the United States and elsewhere.

“A wealth of experience now exists on how to conduct effective global change assessments,” says the report. The challenges common to any such effort include clearly framing the assessment’s mandate, engaging stakeholders, and weighing the benefits against the time and resources spent. The report also weighs in on the pros and cons of various assessments conducted to date (see sidebar).

The full report and a four-page summary can be accessed online.

	Analysis of Global Change Assessments: Lessons Learned Four-page summary (PDF)

A report card on recent assessments The strengths and weaknesses of a variety of recent assessments were analyzed by a National Academies panel whose report was published in February. Below are some of the key points.
WMO/UNEP stratospheric ozone assessments 1985, 1989, 1991, 1994, 1998, 2002, 2006 Pros: Excellent leadership, met the needs of decision makers, proved effective in mobilizing participants Cons: Frequency of reports (every four years) has become somewhat burdensome; industry participation has waned www.esrl.noaa.gov/csd/assessments	Arctic Climate Impact Assessment (ACIA) 2004 Pros: Clear and strong mandate, support from decision makers, well-planned communications strategy, transparent model for science-policy interface Cons: Economic impacts not considered; follow-up activities could have been better defined www.acia.uaf.edu
Intergovernmental Panel on Climate Change (IPCC) 1990, 1995, 2001, 2007 Pros: Well-developed organizational structure, strong ties to scientists and governments, high credibility, effectively serves multiple audiences Cons: Could use stronger coordination among individual working groups; needs to consider the burden on scientists and the rate at which new knowledge emerges www.ipcc.ch	Millennium Ecosystem Assessment (MEA) 2005 Pros: Broad participation (business, industry, academia, nongovernmental organizations, UN agencies, indigenous groups), well-designed conceptual model Cons: Could have used more direct government interaction, follow-up activities www.maweb.org/en/index.aspx
Global Biodiversity Assessment (GBA) 1995 Pros: High scientific credibility, involvement of world’s leading scientists in the field Cons: Lack of government authorization and subsequent acceptance; hindered by limited budget for outreach and working-group interaction No Web site; report is available in print from Cambridge University Press	German Enquete Kommission on “Preventive Measures to Protect the Earth’s Atmosphere” 1991 Pros: Good support and participation from political decision makers, broad participation by stakeholders and various experts, good communications strategy Cons: Some hindrance of assessment process by parliamentarians who had little expertise in the topic or whose political agendas clashed No Web site
[U.S.] National Assessment of Climate Change Impacts 2000 Pros: Well-defined mandate, clearly articulated questions, broad range of stakeholder involvement, well-planned communications strategy Cons: Difficulties in phasing assessment steps, uneven funding availability, limited impact on U.S. policy or research direction www.usgcrp.gov/usgcrp/nacc	U.S. Climate Change Science Program (CCSP) Synthesis and Assessment Products Set of 21 reports now in process; first report issued in 2006 Pros: First report resolved long-standing discrepancy on temperature trends in lower atmosphere; subsequent reports may be effective in other areas Cons: Unclear whether products will provide an integrated view of climate change impacts and possible response options www.climatescience.gov