How to read the latest science report from the IPCC

Something unfortunate happened on the way to the release the latest report from the UN Intergovernmental Panel on Climate Change (IPCC). The IPCC press release noted “ The evidence is clear: the time for action is now. We can halve emissions by 2030” The statement conveyed to the public: Scientists say the time for climate action is now.

What is wrong with that? 

Nothing, except it ignores the role of this report in IPCC’s larger findings.

This depiction of scientists’ call to action misses the conditionality of the true message of the report: If we want to limit warming to below thresholds of what we might consider to be “dangerous interference with the climate system” (like 1.5 or 2.0 degrees Celsius), then it is more urgent that we act promptly (this decade). IPCC Chair Hoesung Lee put it concisely and more carefully when he remarked that “we are at a crossroads. The decisions we make now can secure a livable future. We have the tools and know-how required to limit warming.”

Unfortunately, the IPCC’s messaging allows the media to interpret the report in words that make it sound like the scientist authors are telling the world what to do. Specifically, they are, as reported by the BBC, saying that there must be “rapid, deep and immediate” cuts in carbon dioxide (CO2) emissions.” 

And what is the harm of taking a little license in writing a title? It again makes an IPCC report a slow-moving target for those who want humanity to dismiss its entire content because the authors have shown their bias by stepping outside of their sandbox. More importantly, it allows critics to assert that the IPCC should not be trusted because it has strayed beyond the scope of its legal authority.

In fact, the 278 authors of this most recent IPCC report did not stray beyond their areas of expertise — and I can tell your from experience that  the institution would not have allowed them to do so even if they had tried. In this report, which is part of a larger Sixth Assessment Report (AR6), scientists have assessed the state of knowledge about mitigation; and they now report, with attached expressions, of very high confidence that: 

1.       We are not on track to hold warming below 1.5 degrees Celsius.   

2.       Immediate and robust action by 2025 and 2030 is required, ifwe want to hold warming below 1.5 degrees and even 2.0 degrees, respectively.  

3.       The prices of supporting alternative sources of energy have fallen dramatically and market adoption has been rising accordingly.  

4.       Mitigation actions can support all 17 Sustainable Development Goals. 

To understand the importance of these findings fully, it is essential that readers of this third part of the AR6 are familiar with its context. This week’s report on mitigation of climate change was drafted by IPCC’s Working Group III speaks only to abating emissions over time. It follows that it could not possibly prescribe mitigation policy targets because it assesses neither climate impacts (that’s the purview of Working Group I whose contribution to AR6 was finalized on Aug. 6, 2021) nor net risk post adaptation (the purview of Working Group II whose contribution was finalized on Feb. 27, 2022). 

It will not be until the release of the Synthesis Report of the AR6, which is scheduled to be finalized Sept. 30, 2022, that signatories of the United Nations Framework Convention on Climate Change will have access to the fruits of its complete and integrated assessment of climate risk and possible climate action.  It will be up to them to apply this new information to their next evaluation at the next UN climate summit, the 27th meeting of Conference of the Parties (COP27) in November, of what constitutes a level of tolerable level of global climate risk with regard to humanity’s “dangerous interference in the climate system”.   

It is the conference members representing their own countries, and not the scientists, who will tell us what we should do. 

Gary Yohe is the Huffington Foundation professor of economics and environmental studies emeritus at Wesleyan University. He served as convening lead author for multiple chapters and the Synthesis Report for the IPCC from 1990 through 2014.