The IPCC’s longstanding framework for detection and attribution looks DOA in AR7

The Intergovernmental Panel on Climate Change (IPCC) has just released the names of its authors for its seventh assessment report (AR7). The author list for its Chapter 3 — Changes in regional climate and extremes, and their causes — suggests strongly that the IPCC will be shifting from its longstanding focus on detection and attribution (D&A) of extreme events to a focus on “extreme event attribution” (EEA).

Roger Pielke Jr. has the story.

Let’s first briefly clarify how these concepts are different and why the difference matters.

• The IPCC D&A framework follows from its definition of “climate change” as a change in the statistics of weather over long time periods, typically many decades. Detection refers to identifying such a change. Attribution refers to identifying causes of that change. For most extreme weather phenomena, the IPCC has not achieved detection or attribution with high confidence and does not expect to for most this century.
• In part due to the IPCC’s failure to achieve D&A for most types of extreme events, the notion of EEA was invented to connect specific weather events with changes in climate and characterized as an effort to get into the media and support climate litigation. Most EEA work is published outside of the scientific literature, announced by press release, and is typically contrary to peer-reviewed research on extreme events.
• The D&A framework is scientifically rigorous, consistent with the IPCC”s definition of climate change, and treats extreme events in the same manner as other phenomena, like global temperatures and sea level rise. The EEA approach is scientifically problematic, inconsistent with the IPCC’s findings on extreme weather, and is explicitly grounded in climate advocacy.

The IPCC AR6 was decidedly lukewarm to freezing cold on the notion of EEA, and emphasized the traditional D&A framework. Those days may now be over.

World Weather Attribution (WWA) co-founder Frederika Otto has been put in charge of the chapter, along with another academic who focuses on extreme event attribution.

Otto explains today:

I’m a coordinating lead author. This means leading the chapter, and ultimately being responsible for making it happen. It’ll be a lot of work, but it also gives a lot of opportunity to shape the structure and focus of the chapter.

The chapter’s author list shows that it is stacked with people who focus on extreme event attribution — far out of proportion to their presence in the field. With the help of Google Scholar and ChatGPT I created the table below, which shows that 9 of the chapter’s 20 authors focus their research on extreme event attribution. Two of the three coordinating lead authors focus on EEA. Few of the authors, if any, have expertise in the IPCC’s conventional framework for detection and attribution, and some have no publications on either detection or attribution.

Of note, in addition to Otto, the chapter includes a second WWA collaborator. The Bezos Earth Fund partially funds WWA along with the U.S. National Academy of Sciences ongoing study of extreme event attribution. At least five of the 20 chapter authors have participated in some way in that study.

Read the full story here.