World Ecosystem Extent Dynamics (WEED), a toolbox for countries to report on GBF Headline indicator A.2

Ecosystems are fundamental to the planet’s environmental and socio-economic systems, and assessing their condition and services begins with understanding their extent. Developing reliable, standardized and scalable methods for mapping ecosystem extent and change is urgently needed, yet remains a significant challenge. Ecosystems’ inherent diversity, their natural complexity and the variation in their definition complicate efforts to delineate boundaries clearly and represent individual cases correctly.The World Ecosystem Extent Dynamics (WEED) platform is a globally applicable, open-source toolbox designed to support countries and regions to generate extent maps of terrestrial, freshwater and coastal ecosystem types and their temporal dynamics, according to different typologies. Provided as an Earth Observation (EO)-integrated, end-to-end processing system, WEED runs on cloud computing infrastructures and complies with Open and FAIR principles. It offers both graphical and command-line interfaces to support users with varying technical capacities, enabling data upload, analysis, visualization, export, and access to intermediate results with full workflow transparency and reproducibility.The WEED solution combines data-driven (Machine Learning) methods with expert-based approaches to analyse geospatial proxy data, including EO imagery, environmental datasets, crowdsourced inputs and local measurements. Its modular design creates a federated system that integrates state-of-the-art components, including the ARIES semantics platform, the OpenEO processing platform, and the Laco-WIKI reference data platform, applying a digital twin concept. Co-developed with six countries, WEED allows users to upload national reference data for model training and extent mapping tailored to local contexts. In addition to ecosystem extent maps, the toolbox delivers outputs for key policy indicators, such as the Ecosystem Extent accounting tables (UN SEEA-EA) and the Global Biodiversity Headline Indicator A.2 (UN CBD GBF), which can also be extended to other indicators.The WEED platform development is a project funded by the European Space Agency (ESA), and a technology contribution to the Global Earth Observation Atlas initiative (GEO-Atlas). The presentation will introduce participants to the upcoming toolbox (planned release in 2026) and show practical results from the co-creation with countries.