Compliance carbon markets continue to be at the core of global climate mitigation efforts and raised a record USD 74 billion in revenues in 2023. In 2024, 36 Emission Trading Systems (ETSs) are in force, covering approximately 18% of global emissions. In addition, 22 ETSs are being developed or considered. Japan, Canada, Brazil, India, and Türkiye, for example, are taking important steps towards launching new ETSs. - Major compliance markets underwent significant reforms in the past year to align them with climate- or carbon-neutrality commitments or to cover new emitters. Sector expansion and possible integration of removals are two emerging themes in key systems. - Article 6 of the Paris Agreement establishes different market mechanisms that countries can use to cooperate in achieving their climate targets by trading emission reductions or removals with each other.