A Takeover of the IPCC–Roger Pielke

By Paul Homewood

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).

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.

Full story here.