For the first time a delegation of BIPM staff attended the United Nations Climate Change Conference demonstrating BIPM's commitment to promote the importance of metrology with key stakeholders. During the mission, the delegation laid a foundation for collaboration with various liaison organizations at future COP conferences.

The delegation was able to highlight the importance of metrology in several stakeholder events, including a session on the Interplay of regulation and standards in the hydrogen economy: ensuring trade, trust, traceability and transparency. This session, organized by UNIDO, DIN and Hydrogen Europe on 5 December, underscored the significance of accurate metrological standards and reference materials in ensuring the traceability of hydrogen production, distribution, and storage. It also emphasized the importance of mutual recognition of calibration certificates at a global scale. A first key comparison in measuring hydrogen purity (CCQM-K164) will be launched in 2024.

The delegation also participated actively in Earth Information Day, held on 2 December. This event, organized by the World Meteorological Organization (WMO), served as a global gathering of climate scientists. Metrology's contribution to improving measurements in climate science emerged as a prominent theme during the event. BIPM plans a Stakeholder Workshop scheduled for September 2024, where experts from the Intergovernmental Panel on Climate Change (IPCC), the Subsidiary Body for Scientific and Technological Advice (SBSTA), and WMO will be invited to discuss the role of metrology in climate science.

Looking ahead, the CIPM Sectorial Task Group on Climate Change and Environment will coordinate involvement in relevant technical committees, collaboration with national representatives from the metrology community at COP meetings, and partnerships with liaison organizations to emphasize the critical importance of quality infrastructure in advancing climate action.