RCP8.5 Is Dead, What Comes Next? Ep260: Roger Pielke, Jr.

For more than 15 years, the RCP8.5 climate scenario has shaped headlines, policy decisions, financial stress tests and public understanding of climate risk. Now, the scientific community has declared it implausible. So what comes next?

This week on Cleaning Up, Michael Liebreich welcomes Professor Roger Pielke Jr. back to explore why RCP 8.5 became the dominant "business as usual" climate scenario, and what its demise means for climate research, policymaking and public debate.

They discuss the origins of the scenario, how assumptions about coal consumption drove projections beyond plausible futures and ask whether fear-based climate communication has ultimately helped or hindered public support for climate action. They tackle tipping points, extreme weather, climate policy, scientific self-correction, and the crucial question of how societies should respond to climate risk in a world that is still warming.

Until recently, Roger was a tenured professor at the University of Colorado at Boulder. He is now senior fellow at the American Enterprise Institute and publishes an influential Substack called The Honest Broker. He last made an appearance on Cleaning Up in June 2022. If you want to know the background to the RCP8.5 controversy you should listen to that episode, linked below.

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Links:

• Van Vuuren’s 2026 paper on RCP8.5 becoming implausible: https://gmd.copernicus.org/articles/19/2627/2026/
• Van Vuuren’s 2011 paper on the development of the Representative Concentration Pathways (RCPs): https://link.springer.com/article/10.1007/s10584-011-0148-z
• The Honest Broker Substack: https://rogerpielkejr.substack.com/
• Michael's writeup on RCP8.5: https://mliebreich.substack.com/p/rcp-85-is-officially-bollox
• Roger Pielke Jr’s past appearance on Cleaning Up: https://www.youtube.com/watch?v=K2LpMpkrP1w
• Johan Rockström on Cleaning Up: https://youtu.be/eIJkt_mY12s
• Jim Skea on Cleaning Up: https://youtu.be/oAWUdL5ZKsk