Climate Change 1995: Impacts, Adaptations and Mitigation of Climate Change: Scientific-Technical Analyses. - book reviews

Ecology, Dec, 1997 by Anthony C. Janetos

Reviewing a complete volume of any of the Intergovernmental Panel on Climate Change's (IPCC) various assessments is a daunting job. This review focuses on the "Impacts and Adaptation Assessment of 1995" (R. T Watson and M. C. Zinyowera, Co-Chairs), which is the second full "Impacts Assessment" undertaken by IPCC. In the spirit of full disclosure, I should state that I was a participant in the first "Impacts Assessment," which was co-chaired by Australia and the (then) Soviet Union; the U.S. Co-Chair of the second is a close collaborator on many projects.

The issue of climate change and its potential impacts is so intrinsically interdisciplinary that it should be interesting to any environmental scientist, and ought to be important to any policy-maker concerned with the sustainable management and use of natural resources. The outlines of the issue are clear: human activities are altering the chemical composition of the atmosphere in ways that, other things being equal, are likely to lead to substantial global and regional changes in the climate system, with subsequent ecological and other environmental effects. The challenge of describing the state of the science in both the underlying climatic issues and in the potential impacts and possible response strategies is thus an enormously important chore that the governments of the world have assigned to the IPCC.

Reviewing the "Impacts Assessment" is particularly challenging, in part because the IPCC itself artificially separates the discussion of potential impacts, adaptation, and mitigation strategies from the assessment of the state of the science. This separation has resulted in several independent discussions of ecology, hydrology, and other environmental sciences. In order to overcome some of the problems introduced by this separation, the "Impacts Assessment" begins with two sections that are technical primers on ecological and economic issues. These primers are interesting, well written, and are clearly necessary only because of the separation of science, impacts, and mitigation.

The intent of the IPCC assessments and the process by which they are produced are important to keep in mind, for they shape the volumes in ways that are generally unfamiliar to most scientists. None of the IPCC assessments are meant to be primary research volumes. They are summaries and evaluations of the state of science, meant primarily for policymaking audiences. By their own rules, they are meant to use only published results, which inevitably means that by the time they are published, the bibliographies appear somewhat out of date. Authors are nominated by governments (signatories of the Framework Convention for Climate Change) and by the Bureau of the IPCC itself. However, authors are explicitly not selected as representatives of governments, but on the basis of their technical expertise, keeping in mind the appropriate geographic balance necessary in any large, intergovernmental, international process. The lead authors for each chapter produce an outline, which must be approved by the intergovernmental body, and must adhere to an agreed-on schedule, but then are free to write whatever they will.

The constraints on the lead authors are generally two-fold. First, they are expected to review the literature thoroughly, and to involve a large number of co-authors, generally listed as authors or contributors. This collection of lead authors, co-authors, and contributors is expected to reflect a community consensus on the science covered within each chapter, rather than their own views and evaluations of the literature. Second, chapters are expected not only to describe a consensus on scientific issues where one exists, but, where consensus does not clearly exist, to discuss reasonable minority views, when these are sufficiently well documented in the literature. Lead authors bear the final responsibility for the content of each chapter, and thus exercise substantial editorial authority. The individual chapters thus tend to be extensively referenced, and the bibliography alone is generally a quite reasonable description of the state of the appropriate literature at the time of the last review.

Although by most academic standards, the IPCC Assessments are "gray literature," they are among the most thoroughly reviewed scientific documents in the world. There are two independent sources of review. First, the IPCC itself sends copies of the chapters to reviewers around the world, chosen only for their scientific expertise. Second, the sponsoring governments also send the chapters out for review by experts of their choosing. Neither review is anonymous. Lead authors are required to respond to every substantive review comment, indicating whether they have taken it into account or rejected it. The result is that each chapter in the "Impacts Assessment" has undergone substantial review by scientific peers around the world, with an enormous amount of documentation of the fate of each review comment.