The IPCC has released an intermediate stage of its methodology report on inventories for Short-Lived Climate Forcers (SLCF) for review. Governments and specialists are invited to examine the Second-Order Draft (SOD). The final report is scheduled for publication in the second half of 2027.
What SLCF are
Short-Lived Climate Forcers include substances such as methane, black carbon, F-gases, ozone precursors and certain aerosols. They remain in the atmosphere for days to a few decades but can contribute substantially to warming and affect air quality.
Why a methodology report matters
National emissions inventories are central planning and reporting tools in climate policy. While established procedures exist for long-lived greenhouse gases, SLCF sources and processes are more heterogeneous and harder to quantify. The IPCC report aims to provide standardized methods, calculation approaches and uncertainty assessments. Consistent procedures improve comparability between countries and support short- and medium-term mitigation planning.
Review process
The Second-Order Draft phase combines review by governments and external experts. Technical comments on scientific foundations, methodology and applicability will be incorporated into revisions. The objective is to ensure transparency, quality and acceptance of the final document.
Who can register
The call is aimed at experts from research, government agencies, national inventory teams, civil society and industry with relevant expertise. Registration is handled through the IPCC registration system. National IPCC focal points can also nominate reviewers.
Contents of the draft
The report builds on existing inventory guidelines and extends them for SLCF. It includes updated emission factors, improved methods for uncertainty analysis and approaches for hard-to-quantify sources such as open biomass burning or informal agricultural practices. The draft also addresses short-lived, high-impact substances such as black carbon particles.
The draft also considers integrating remote sensing, satellite observations and monitoring networks into national inventories. These data can help fill gaps and support plausibility checks.
Significance for policy and practice
More accurate inventories make it easier to prioritize effective mitigation measures, for example targeting methane emissions in the oil and gas sector, in waste management or in the management of open fires. A robust data basis links climate protection with air quality and health objectives and strengthens the credibility of short-term contributions.
Outlook
With the SLCF methodology report, the IPCC reinforces the link between research and applicable policy support. The ongoing review is a key step to refine the guidance technically before its publication in 2027.