The limitations of CCS and CDR and their grip on our future climate

While their technical details are clear, scientists have questions about the scale at which CCS and CDR are expected to succeed.

Unraveling the Complexities of Carbon Abatement Technologies at COP28

• New Technologies: The ongoing COP28 climate talks in Dubai have brought to the forefront the discussions around carbon capture and storage (CCS) and carbon-dioxide removal (CDR) technologies, with a particular emphasis on the contentious term "abatement."

Understanding CCS and CDR Technologies

• Deciphering CCS: CCS, or carbon capture and storage, encompasses technologies designed to capture carbon dioxide (CO?) emissions at their source, preventing their release into the atmosphere.
• Unveiling the Forms of CDR: CDR, or carbon-dioxide removal, takes various forms, ranging from natural methods such as afforestation and reforestation to advanced technologies like direct air capture.
  • Enhanced rock weathering and bioenergy with carbon capture and storage (BECCS) are among the more intricate CDR technologies, each playing a unique role in mitigating carbon emissions.

Unraveling the Controversy of "Unabated Fossil Fuels" at COP28

• Unabated fossil fuels: The term "unabated fossil fuels" has become a contentious point of discussion at COP28, specifically in the context of combustion without utilizing CCS technologies to capture emissions.
  • Phase out: Draft decisions at the conference emphasize the need to "phase out" such unabated fossil fuels, revealing the complexities of aligning diverse perspectives.

The Scale and Challenges of CCS and CDR

• Technical details of CCS and CDR: While the technical details of CCS and CDR are clear, questions arise regarding their scalability and effectiveness.
• The Sixth Assessment Report (AR6) by the IPCCunderscores the reliance on CDR for achieving the goal of limiting global temperature rise to 1.5 degrees Celsius. However, concerns about the scale of implementation and the necessity of these technologies persist.

Navigating the IPCC's Emission Scenarios

• The IPCC's emission scenarios for limiting warming to 1.5 degrees Celsius highlight the need to sequester 5 billion tonnes of CO? by 2040.
  • This ambitious goal raises questions about the feasibility and implementation challenges, especially considering it surpasses the annual emissions of a major emitter like India.

The Crucial Role of CDR in Mitigation Strategies

• CDR in mitigating climate change: Scientists emphasize the indispensable role of CDR in mitigating climate change, particularly in scenarios where direct mitigation through renewable energy sources may prove insufficient.
• The strategic use of CDR becomes crucial to counterbalance hard-to-abate residual emissions, as outlined in the IPCC AR6 report.

Analyzing the Effectiveness of CCS

• Challengesof CCS: Despite being recognized as a key technology, CCS faceschallenges related to its effectiveness, feasibility at a large scale, high costs, and potential environmental impact.
• Highly effective CCS: The distinction between "abated" and "unabated" fossil fuels hinges on the application of highly effective CCS, emphasizing the need for a capture rate of 90-95% or more.

Scrutinizing CDR Technologies

• Limitations: While CDR technologies like afforestation, reforestation, and BECCS offer potential solutions, they are not without limitations.
• Land Issues: Concerns about land use, equity issues, and potential conflicts with other land-dependent activities, such as agriculture, underscore the complexities of deploying large-scale CDR methods.

Pitfalls and Dilemmas of CCS and CDR

• Creating more emissions: The deployment of CCS and CDR raises concerns about creating more room for emissions, potentially offsetting their intended benefits.
• Increased Emissions: The paper explores the pitfalls of these technologies, including their potential use to extract more oil, the role of land in CDR methods, and the overarching question of who will bear the financial burden of implementing CDR at scale.

Way Forward: The Decade Ahead: Crucial Questions and Future Prospects

• The article concludes by highlighting the pivotal role of the next decade in determining the viability and scalability of CDR methods.
• It underscores the need for addressing questions related to land use, equity, and financial responsibilities, while also recognizing the broader global perspectiveson climate adaptationversus extensive investment in CDR technologies.