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Roger Pielke Jr.: ‘How Democrats Left the UN IPCC Behind – ‘Democrats — not all, but many — have left the IPCC behind in favor of an extreme view of climate and extreme events’

Partisan realignment on the science of climate change


On Wednesday, I’ll be testifying before the Senate Committee on the Budget in a hearing titled, “Droughts, Dollars, and Decisions: Water Scarcity in a Changing Climate.” My testimony is embargoed until then, but after the hearing, I will post my oral and written testimony here and I will be happy to engage questions and comments.

I have been invited by the minority (Republicans) and asked to summarize for the committee the findings of the Intergovernmental Panel on Climate Change (IPCC) on drought. The first time I testified before the Senate, in 2002, I was invited by Democrats and I was similarly asked to summarize the findings of the IPCC on extreme events.

That has me thinking about how the views of the IPCC, Democrats, and Republicans1 (and my own views as well) may have changed over the past several decades on the science of climate change — and on extreme weather and climate events specifically.

As I will relate in my testimony on Wednesday, the IPCC (Working Group 1) has been remarkably consistent in its periodic assessment reports in its findings on the detection and attribution of trends in extreme events. My research with many colleagues over decades has often been cited in those assessments, and — looking back at my past peer-reviewed studies, commentaries, and testimonies — my views have developed over time but also stayed highly consistent and also consistent with the findings of the IPCC.

Thus, the fact that Democrats used to invite me to testify about the IPCC and now Republicans do cannot be explained by a change in the findings of the IPCC or a rethinking of my own perspectives.

Instead, it’s my observation and experience that the views of the political parties on the assessments of the IPCC has shifted dramatically over the past several decades.2 The schematic below shows my impression of how things looked in 2002, when I first testified before Congress. At that time, Democrats, for the most part, had views on climate change and extreme events largely in line with the findings of the IPCC. I’d venture that this is why I was invited by Democrats at the time to testify.3

Flash forward to 2024. Much more research has been published and three further IPCC assessments have been produced. Over this time, the IPCC’s bottom-line findings on climate and extreme events have become better supported with evidence and research.

In 2024, here is how I see views of the assessments of the IPCC in the current U.S. Congress.

Democrats — not all, but many — have left the IPCC behind in favor of an extreme view of climate and extreme events. Republicans — not all, but many — find themselves much more in line with the findings of the IPCC on climate and extreme events. Similarly, I’d guess that explains why in recent years I’ve been invited to testify by Republicans.4

Of course, consistency with the IPCC (or not) says little about policy preferences. Democrats remain the party championing action on climate policy and Republicans remain much less supportive. Of course, the key question here is, What action? I have long argued that there are unexplored opportunities for greater bipartisan support for pragmatic energy and adaptation policies that would accelerate decarbonization and reduce vulnerabilities — but that’s a topic for another day.