Advancing the global statistical standard for urban ecosystem accounts

• Challenges for standardising thematic urban ecosystem accounts are identified. • Global scarcity of urban ecosystem accounting pilots’ limits framework development. • Socio-technological variables are required to capture urban ecosystem degradation. • Challenge interdependencies require a stepwise prioritisation of their resolution. • Stakeholder engagement and agreed global policy themes are key for standardisation. The System of Environmental-Economic Accounting-Ecosystem Accounting (SEEA-EA), adopted by the United Nations, provides a standardised global framework for measuring and monitoring the extent, condition, and services of ecosystems. However, its application to urban ecosystems faces conceptual and operational challenges. With the aim of advancing the SEEA-EA framework for thematic urban ecosystem accounting, we identify key challenges and frame potential solutions based on existing lessons and approaches. Through a review of scientific and grey literature, we identify 24 challenges, with lessons and approaches suggested for 17 of them. Many challenges are highly interconnected and shared with accounts for other ecosystem types. Still, urban ecosystems present specific challenges, such as the lack of a global classification scheme, ambiguity in defining urban ecosystems and determining which assets belong to them, and persistent gaps in fully capturing urban ecosystem degradation. To address the identified challenges, we propose solutions, such as the development of a complementary ‘sister’ condition table to account for socio-technological variables, the integration of scenario modelling into monetary ecosystem asset accounts to reflect future projections and uncertainties, and the definition of internationally agreed policy uses to ensure consistent implementation. We also highlight the need for a careful prioritisation of the next steps based on the interdependencies among challenges. By mapping challenges, synthesizing lessons and approaches, and framing solutions, this study contributes to moving towards a globally standardised thematic urban ecosystem accounting framework. Such standardisation will enhance the relevance of SEEA-EA thematic urban ecosystem accounts in informing urban sustainability policies.