Instructive timing is at work in the publication this month and last of two major reports in the Fifth Assessment by the Intergovernmental Panel on Climate Change. Covering possible consequences of a changing climate and what to do about them, the reports should be read together.
In fact, the reports will be blended with an earlier report into a "synthesis report" in October. The earlier report, on physical science, emerged from Working Group 1 in September. Working Group 2 published its findings on impacts, adaptations, and vulnerability at the end of March. Working Group 3, meeting in Berlin, treats mitigation this week.
Science and politics
The IPCC assessments, conducted under auspices of the United Nations Environmental Program and World Meteorological Organization, are comprehensive, lengthy, and important updates of knowledge about climate change. Hundreds of scientists work on them. Since publication of the First Assessment in 1990, each has triggered controversy in science and politics, spheres that long ago became barely distinguishable where this topic is concerned.
Especially useful in the Fifth Assessment schedule is the lapse of only 13 days between the close of the Working Group 2 meeting in Yokohama, Japan, and that of Working Group 3 in Berlin. It suggests a pairing of topics that, if it became a pattern, might improve a discussion about climate change by balancing inherent alarmism with natural resistance to sacrifice. So far, that balance has been missing.
The IPCC's working groups give structure to the climate-change narrative. Science (Working Group 1) documents warming coincident with the age of industrialization, with its increased use of fossil energy and consequent buildup in the atmosphere of carbon dioxide and other greenhouse gases. Effects of warming (Working Group 2) are increasingly evident. Response (Working Group 3) is in order. Contrary to persistent allegations, few observers deny any of this. The controversy—scientific and political—is about degree: How much of the observed warming is attributable the use of fossil energy? How much response therefore is in order when the necessary changes would be certainly costly yet uncertainly effective?
An aggressive political agenda has developed around climate change that concentrates—some say exaggerates—effects, demands urgent response regardless of cost, and insists that science is "settled," or at least conclusive enough to warrant overhauling energy systems. Proponents of this agenda have treated dissenters as cranky "deniers" unworthy of consideration. Their approach is demonstrably incorrect. Many distinguished scientists disagree with, or at least raise serious questions about, assertions motivating the aggressive political agenda. And if the science indeed had been "settled" as long as some have claimed it to be, why does IPCC bother to conduct a painstaking scientific assessment every few years?
The aggressive approach also is beginning to feel backfire from its own importunity. Anticipating a suggestion of Working Group 3 of IPCC's Fourth Assessment in 2007, European governments eager to lead the world in climate-change mitigation adopted feed-in tariffs for renewable energy. Now European economies are struggling under the weight of high energy costs as European voters reject programs elevating their electricity bills. Also in line with a recommendation of the same working group, the US adopted renewable-energy obligations that have proven overly ambitious and increasingly unworkable. It was unknown at this writing whether the corresponding working group of the Fifth Assessment saw fit to accommodate its recommendations in those areas to stark experience.
Positions in the politics of climate change hardened long ago. But reality enforces balance. It's doing so now as economic casualties mount from the full frontal attack on a problem of vague dimension. Promoters of the aggressive agenda need to worry about their political support.
Climate change shouldn't be a winner-takes-all issue—scientific or political. It should be one in which caution applies as much to cost as it does to climate. Balance such as that would serve the discussion well. Now would be a good time to try it.