Who’s the real U.N. climate chief?

Many readers are no doubt understandably confused by journalistic shorthand that often labels two different guys — Yvo de Boer and Rajendra K. Pachauri — the U.N.’s "climate chief." De Boer’s resignation just went public today, and Pachauri has been in the news a lot lately over "Climategate," so I’m sure the confusion is only going to get worse.

Until he formally steps down on July 1, De Boer will remains the executive secretary of the United Nations Framework Convention on Climate Change, which is the organization that implements a 1992 treaty called… the United Nations Framework Convention on Climate Change. De Boer heads a staff of about 200 people and reports to the U.N. secretary general. His main task has been coordinating efforts to get a new global treaty passed to replace the 1997 Kyoto Protocol, the first attempt to get countries to commit to reducing their emissions of greenhouse gases. And he was the U.N.’s point man for last December’s Copenhagen summit, though it was the Dutch who handled most of the logistics of the meeting.

Pachauri heads up a separate entity called the Intergovernmental Panel on Climate Change, which is charged with reviewing the literature, pulling together scientific assessments on climate change, and putting them in a format policymakers can digest. It’s technically accurate to say it’s a U.N. body, but somewhat misleading, as it’s really an organization made up of member governments. The RealClimate blog has a concise primer on the IPCC here:

Let’s start with a few basic facts about the IPCC.  The IPCC is not, as many people seem to think, a large organization. In fact, it has only 10 full-time staff in its secretariat at the World Meteorological Organization in Geneva, plus a few staff in four technical support units that help the chairs of the three IPCC working groups and the national greenhouse gas inventories group. The actual work of the IPCC is done by unpaid volunteers – thousands of scientists at universities and research institutes around the world who contribute as authors or reviewers to the completion of the IPCC reports. A large fraction of the relevant scientific community is thus involved in the effort.  The three working groups are:

Working Group 1 (WG1), which deals with the physical climate science basis, as assessed by the climatologists, including several of the Realclimate authors.

Working Group 2 (WG2), which deals with impacts of climate change on society and ecosystems, as assessed by social scientists, ecologists, etc.

Working Group 3 (WG3) , which deals with mitigation options for limiting global warming, as assessed by energy experts, economists, etc.

Assessment reports are published every six or seven years and writing them takes about three years. Each working group publishes one of the three volumes of each assessment. The focus of the recent allegations is the Fourth Assessment Report (AR4), which was published in 2007.  Its three volumes are almost a thousand pages each, in small print. They were written by over 450 lead authors and 800 contributing authors; most were not previous IPCC authors. There are three stages of review involving more than 2,500 expert reviewers who collectively submitted 90,000 review comments on the drafts. These, together with the authors’ responses to them, are all in the public record.

So, to summarize: The IPCC does science; the UNFCC does politics and policy.