Revisiting the challenges to monitoring, evaluation, reporting, and learning for climate adaptation

Monitoring, evaluation, reporting, and learning (MERL) is a key mechanism for advancing climate change adaptation by enabling reflection, preparation and improvement. While challenges to MERL are typically grouped into conceptual, empirical, and methodological categories, emerging issues demand attention as adaptation practice matures. These challenges are pressing for two reasons. First, the maturing field of adaptation introduces complex challenges beyond technical considerations, yet risks perpetuating structural problems seen in other MERL domains. Second, adaptation is inherently transversal, spanning multiple policy arenas—local to global, and across sectors such as environment, development, transport, water management, and education—further multiplying the diversity of challenges. Through a scoping review of scientific and grey literature, we synthesised a framework of emerging challenges to designing, implementing, and using MERL for adaptation. These include ontological challenges (how adaptation and related concepts are defined and contested), epistemological challenges (whose knowledge counts, and how it is valued), axiological challenges (nature and types of value being placed on MERL), social challenges (equity and justice aspects in MERL processes affecting effectiveness), material challenges (use of financial and human resources), political challenges (dynamics affecting transparent evaluation), and spatio-temporal challenges (integration of complex spatial and temporal dimensions). This framework highlights key gaps and needs in current MERL practices. By addressing these challenges, adaptation policy and science can advance in ways that are more grounded, equitable, and effective, enabling improved responses to the complex and evolving demands of climate change adaptation. • Challenges to MERL for adaptation are now theoretically conceived as mainly conceptual, empirical, and methodological. • MERL for adaptation has faced an evolution due to expanding practice and transversality across scales and sectors. • We gather evidence of more diverse challenges from a scoping review of scientific and grey literature. • New challenges cover ontological, epistemological, axiological, social, political, material, and spatio-temporal categories. • Updating our understanding of these challenges illuminates pathways towards more grounded, fair, and effective MERL.