How do we Remove 1.7 Trillion Tons of CO₂?

How do we Remove 1.7 Trillion Tons of CO₂?

by Clean Power Hour

Applied Sciences & Engineering Engineering & Technology TQEnvironmental science, engineering and technologyTQPGreenhouse gas emissions technologies
🎙 Clean Power Hour 👥 11K 📅 August 18, 2026 ⏱ 37 min 👁 1 📄 interview 🧭 2026-08-18
Available in: English (current) Français

Keywords

enhanced rock weatheringcarbon dioxide removalcarbon creditsnet zeroclimate policy

Summary

In this episode of the Clean Power Hour, host Tim Montague interviews Jim Mann, CEO and founder of Undo, a company specializing in enhanced rock weathering (ERW) as a carbon dioxide removal (CDR) technology. Mann explains that ERW accelerates the natural weathering of silicate rocks, such as basalt, by spreading crushed rock on agricultural land. This process increases the surface area and exposes the rock to soil moisture and CO2, speeding up the reaction that converts atmospheric CO2 into bicarbonate ions, which eventually reach the ocean and remain stored for approximately 100,000 years. Undo sells carbon removal credits to companies like Microsoft, Barclays, British Airways, and McLaren Racing at around $350 per ton, with expectations of halving the price as the company scales. The discussion covers the limitations of current carbon credit markets, the importance of permanent removal versus temporary offsets, and the role of regulatory frameworks like the EU’s Carbon Border Adjustment Mechanism (CBAM) in creating a compliance market. Mann argues that net zero targets are insufficient and that we must address the 1.7 trillion tons of legacy CO2 already in the atmosphere. He also discusses the potential of other CDR methods, including direct air capture, biochar, and ocean-based approaches, as well as the controversial topic of solar radiation management as a temporary measure. The interview highlights the need for scalable, permanent carbon removal solutions and the economic and policy challenges in achieving them.

235 words

Critical Evaluation

Value of the Information & Strength of the Argument

The interview provides valuable insights into the technical process of enhanced rock weathering and its potential as a scalable carbon removal method. Jim Mann offers a clear explanation of the science, including the acceleration factor of 50,000 to 100,000 times and the permanence of bicarbonate storage in the ocean. The discussion also touches on the economic aspects, such as the current price of carbon credits and the role of regulatory mechanisms like the EU CBAM in creating a market. However, the argumentation is largely one-sided, as Mann is promoting his own company’s technology. The host, Tim Montague, does challenge some points, such as the scalability of ERW and the reliance on voluntary markets, but the conversation lacks a critical examination of potential environmental impacts, such as the energy and resource costs of mining and transporting rock, or the effects on soil and water chemistry. The discussion of other CDR methods is brief and somewhat speculative, without deep analysis of their feasibility or risks.

Scientific Rigor, Source Quality, Title Accuracy

The scientific rigor is moderate. The interview presents technical details about ERW, but these are not backed by specific citations or references to peer-reviewed studies. The sources mentioned are primarily the company’s website and LinkedIn profiles, which are promotional in nature. The title accurately reflects the content, focusing on the challenge of removing legacy CO2 and the role of ERW. The discussion of regulatory frameworks like the EU CBAM is relevant and accurate, but the claims about the permanence of bicarbonate storage and the scalability of ERW are not independently verified. The interview does not address potential criticisms or alternative viewpoints in depth, which limits its scientific credibility.

286 words

Title / Content Match

The title accurately reflects the core topic of the interview, which is the challenge of removing legacy CO2 and the role of enhanced rock weathering.

Quality & Reliability

7/10

The interview features a domain expert (CEO of Undo) discussing a specific carbon removal technology with technical details and references to regulatory mechanisms. However, the information is largely promotional and lacks independent verification or critical examination of the technology's scalability and environmental impacts.

Key Moments

Markers derived by PSI from the transcript: the creator did not define chapters.

Cited Sources

  • Undo Website — Company website providing information about enhanced rock weathering and carbon removal credits.
  • Jim Mann LinkedIn — LinkedIn profile of Jim Mann, CEO of Undo.

Concurring Sources

Dissenting Sources

  • Critique of Enhanced Weathering — A study highlighting potential limitations and environmental risks of enhanced weathering.

External References

Contribution & Novelties

The interview provides a clear and accessible explanation of enhanced rock weathering as a carbon removal technology, highlighting its potential for permanent CO2 storage and its integration with agriculture. It also discusses the economic and regulatory challenges of scaling such technologies, offering insights into the evolving carbon credit market. The conversation touches on the need for a portfolio of CDR solutions and the role of policy in driving demand.

Pour aller plus loin :

107 words

Radar Profile

The radar profile shows moderate scores across all dimensions, indicating a balanced but not exceptional presentation. The content is informative and technically sound, but lacks deep scientific rigor and critical analysis, resulting in a moderate overall quality.

Reliability 6/10

💬 No comments were provided for analysis.