IPCC Opens Expert Review of 2027 CDR and CCUS Methodology Report

The IPCC has set December 11, 2026 as the deadline for expert feedback on the first draft of its 2027 Methodology Report on Carbon Dioxide Removal (CDR) and Carbon Capture, Utilization and Storage (CCUS). The document will govern how national greenhouse gas inventories account for carbon dioxide removals, and once approved, it is expected to shape the development of CDR technologies worldwide.

What is under review?

The draft provides governments with guidelines on how to account for their carbon dioxide removals in national inventories. Roughly 150 Coordinating Lead Authors and Lead Authors assembled the first version during 2026, following a mandate agreed at the IPCC's 63rd session in Lima, Peru, in October 2025.

The Task Force Bureau selected the authors on the basis of scientific and technical expertise, applying geographical and gender balance to the extent possible under Appendix A to the Principles Governing IPCC Work. The IPCC does not promise perfection in composition. It does promise procedure.

The review is now open. Applications are accepted on an ongoing basis until the December 11 deadline.

Who can comment?

The bar for participation is lower than one might expect. Reviewers do not need to be existing IPCC authors, and they do not need expertise across the full scope of the report. During the application process, each participant selects the specific chapters most relevant and familiar to them.

That chapter-level self-selection matters for industry readers. Operators of capture facilities, storage site developers and inventory practitioners can confine their comments to the sections that touch their material streams and accounting obligations.

Why does the methodology matter?

National greenhouse gas inventories are the backbone of climate accounting. How a tonne of removed carbon dioxide enters that ledger determines whether CDR and CCUS projects register as compliance-grade assets or as voluntary-market decoration.

The IPCC states the point plainly: once approved, the publication is expected to have a major impact on the future development of CDR technologies on a global level. The report is expected to win approval by the end of 2027.

For project developers and the agencies that regulate them, the stakes are straightforward. Methodology precedes markets. Markets precede investment at scale.

What happens next?

Two dates decide the trajectory. The review window closes on December 11, 2026, by which point interested experts must have applied. Final approval is expected by the end of 2027, at which point the guidelines become the reference standard for national inventory accounting of carbon removals.

Between those dates sits the unglamorous work of reconciliation: comments gathered, chapters revised, and a methodology refined into something governments can actually implement.

For an industry that has spent years trading on pledges rather than verified tonnage, an agreed accounting rulebook is the milestone worth watching. The deadline for a seat at that table is December 11, 2026.