The Financial Markets Standards Board (FMSB) has published a Spotlight Review updating its assessment of carbon markets, extending its 2022 work on voluntary carbon markets to cover compliance markets as well. The review notes ongoing advances in market design and operation, including broader coverage and tighter emissions caps in multiple jurisdictions’ compliance schemes, alongside improved certification practices in voluntary carbon markets. It also highlights constraints on further scaling, including market fragmentation and limited fungibility of credits across schemes, and points to international cooperation as a key requirement to accelerate progress. Looking ahead, the paper considers potential future integration of voluntary and compliance markets and the linking of national and international frameworks into a single coherent system.