Advances of the ESA Climate Change Initiative (CCI): Progress, Integration, and Future Directions

Systematic observations are essential for understanding the climate system and the changes that are rapidly unfolding. The ESA Climate Change Initiative (CCI) was established to meet the needs of the UNFCCC, supporting the development of long term data records of the Essential Climate Variables (ECVs) defined by GCOS that could most easily be addressed by satellite remote sensing. Since 2009 the CCI programme has built-up European expertise by supporting more than 30 projects that are addressing ECVs, each of which produces multiple data products with detailed documentation to meet the needs of the climate research community and support countries’ goals under the Paris Agreement. Much of this research has been taken up by climate services for the operational production of data, most notably via the Copernicus Climate Change Service (C3S).Co-developed with C3S, ESA CCI has pioneered common data standards, SI traceability, uncertainty characterisation, validation and evaluation processes and detailed product documentation. Furthermore, the metadata requirements from the World Climate Research Programme’s obs4MIPs effort are met by projects on a case-by-case basis, ensuring suitability for climate model evaluation. To date, interoperability and consistency between ECV data records have been more difficult issues to address, but are the target of the next phase of the programme (2026-2029), informed by recent cross-ECV project work. This presentation highlights lessons learnt and future advancements in the CCI programme, with specific examples of how the programme’s integration with strategic partners is supporting improvements for data users, and how the ECV projects are directly working with reporting agencies and contributing to policy need. With the expansion of the Copernicus Sentinel missions up to 2030, and an increasingly diversified landscape of climate data providers, ESA aims to expand its role as custodian and developer of satellite-based ECVs, ensuring European expertise in this area is leveraged to support policy needs for understanding climate change, and tracking mitigation and adaptation action.