Introduction

In the spring of 2005, more than 100 of the world’s leading scientists gathered in the medieval town of Oviedo, Spain, to finalize a landmark U.N. report on a technology billed as a potential climate savior. Carbon capture and storage, or CCS, promised to remove carbon dioxide from smokestacks and inject it deep underground—permanently. Yet the technology had barely been tested, and fundamental questions about storage capacity, monitoring, and leakage risk remained largely unanswered.

The United Nations had been pressured by oil-exporting nations to produce the report despite a scarcity of empirical evidence. Industry researchers from Shell, Chevron, and Saudi Aramco joined the writing team, alongside environmental advocates. To bridge gaps in the data, the group conducted an anonymous expert elicitation survey, asking scientists to estimate storage potential and longevity. The results would become a cornerstone of the final document, even though the method drew sharp criticism from peers who viewed it as informal guessing rather than rigorous synthesis. When the special report was published five months later, it portrayed CCS as a viable pathway that could enable continued fossil fuel use while addressing climate change. Its summary declared no major technical or knowledge barriers to underground storage, citing a likelihood that well-chosen reservoirs would retain 99% of injected carbon for at least 1,000 years.

What Happened

The United Nations had been pressured by oil-exporting nations to produce the report despite a scarcity of empirical evidence. Industry researchers from Shell, Chevron, and Saudi Aramco joined the writing team, alongside environmental advocates. To bridge gaps in the data, the group conducted an anonymous expert elicitation survey, asking scientists to estimate storage potential and longevity. The results would become a cornerstone of the final document, even though the method drew sharp criticism from peers who viewed it as informal guessing rather than rigorous synthesis. When the special report was published five months later, it portrayed CCS as a viable pathway that could enable continued fossil fuel use while addressing climate change. Its summary declared no major technical or knowledge barriers to underground storage, citing a likelihood that well-chosen reservoirs would retain 99% of injected carbon for at least 1,000 years.

Why This Matters

The report’s influence has been profound and far-reaching. Climate models, net-zero pledges, and multibillion-dollar public investments all assumed CCS would deliver on its promises. Governments and corporations poured funding into projects predicated on the report’s assertions, shaping energy policy for two decades. However, the gap between expectation and reality has widened dramatically. Since the Oviedo meeting, large-scale CCS projects have struggled: the In Salah site in Algeria was shut down after CO2 migrated through rock layers, the Norwegian facility had to be relocated after just three years, and the Gorgon project in Australia injected barely a quarter of the captured carbon, falling far short of its 80% target. Independent analyses show that just 12 large-scale geological storage projects operate worldwide, collectively burying less CO2 than a single coal plant emits in a year. Critics argue that the 2005 expert elicitation kept off the record and burned afterward set a precedent for promoting technology with insufficient evidence. Industry funding of academic research, including at Stanford and through IPCC participation, has further entangled CCS credibility with fossil fuel interests. As the climate crisis deepens, the mismatch between policy assumptions and geological reality raises urgent questions about the true role of carbon capture in the energy transition.

Key Takeaways

  • The 2005 IPCC special report on carbon capture was shaped by an anonymous expert survey conducted behind closed doors, despite limited peer-reviewed evidence.
  • Fossil fuel companies actively participated in drafting the report, leveraging it to promote CCS as a climate solution while preserving their core business models.
  • Major CCS projects worldwide have underperformed, shut down, or fallen far short of capture targets, contradicting the report’s optimistic assumptions.
  • Policy and investment decisions built on the report’s conclusions have committed billions of dollars and national climate strategies to a technology with a spotty operational record.
  • The expert elicitation method used in 2005 continues to draw scrutiny from scientists who warn against treating educated guesses as established fact.

Conclusion

Two decades after the Oviedo meeting, the carbon capture story serves as a cautionary tale about how quickly a technology can be elevated from speculative idea to policy cornerstone—especially when industry influence and political pressure converge. As the world races to limit warming, the legacy of that secret vote reminds us that climate solutions must be grounded in robust evidence, not optimistic estimates shaped by commercial interests. The decisions made in those closed-door sessions still echo in today’s energy debates, and the gap between promise and performance demands greater transparency and rigorous scrutiny.