"RCP8.5 Is Officially Dead" – Roger Pielke Jr., American Enterprise Institute

Today we were thrilled to welcome back our good friend Roger Pielke Jr., Senior Fellow at the American Enterprise Institute and author of The Honest Broker on Substack (linked here). Roger’s research focuses on science and technology policy, climate policy, energy policy, extreme events and disasters, the politicization of science, governmental science advice, and sports governance. He is a Professor Emeritus at the University of Colorado Boulder and served as a professor in the Environmental Studies department for over 23 years. We were eager to visit with Roger to discuss the Intergovernmental Panel on Climate Change’s elimination of the RCP8.5 scenario. As always, we value Roger’s perspective and appreciate his insights on the latest trends in climate science and beyond.
 
In our conversation, we explore the evolving state of the decarbonization debate and how energy policy is increasingly being reframed beyond climate alone to include affordability, security, and reliability. Roger walks us through the significant and underreported decision to retire the extreme RCP8.5 climate scenario and explains the flawed assumptions, notably around global coal expansion, that underpinned its widespread use. We discuss the important distinction between scenarios and predictions, and how the misuse of these models shaped policy, regulation, and public perception for over a decade. We examine why climate scenarios have historically lagged real-world developments, the incentives across academia, media, and policy that reinforced reliance on extreme outcomes, and the growing gap between modeled projections and actual energy and emissions trends, including a shift toward more moderate long-term outcomes.
 
We cover the implications for infrastructure, capital allocation, insurance, and regulatory frameworks, including how these scenarios have been embedded in tools such as the social cost of carbon, as well as the need to revisit key inputs like population growth, and how these dynamics are playing out across regions grappling with real-world trade-offs between affordability and decarbonization. Roger highlights the limited awareness and media coverage surrounding these developments, despite their significance. More broadly, he discusses the opportunity to separate climate science from policy debates to enable a more pragmatic and less polarized approach to energy decision-making, while emphasizing the need for more dynamic, diverse, and frequently updated modeling frameworks going forward. It was a fascinating and insightful discussion.
 
Mike Bradley started the show by noting that even after 10 weeks, markets still seem consumed by and are trading on the Iran war. On the bond market front, the 10-year U.S. bond yield moved higher on Tuesday to ~4.45% due to a hot CPI print. U.S. bond yields have been inching higher amid increasing concern of what the Iran war could hold for short/long-term inflation. 
 
On the broader equity market front, the S&P 500 continues to trade near all-time highs (dialing in optimism for an end to the Iran war), which appears somewhat disconnected from other markets. In the past 5 trading days, the S&P 500 was up ~1.5% with the Technology sector outperforming (up ~6%) as it seems to be retaking market leadership.
 
On the oil market front, WTI was trading at ~$102 per barrel (sideways from last Tuesday’s close). WTI price seems to have temporarily settled in an $85 to $105 per barrel trading range, with the lower end dialing in an end to the Iran war and the higher end a continuation. Mike also noted that Saudi Aramco's CEO warned this week that roughly one billion barrels of oil have been pulled from global storage and that an additional 500 million barrels could be pulled (even if the Iran war ends soon), which likely keeps oil prices elevated into 2027.
 
On the Energy sector fron