The discussion how to make baseline setting for international carbon markets consistent with the long-term ambition of the Paris Agreement is playing an important role in the negotiations about Article 6 rules. We propose using an “ambition coefficient” to be applied to baseline methodologies developed under the Clean Development Mechanism (CDM) under Article 6. The coefficient would decline over time – it starts at 100% and falls to 0 in the year when the host country of the activity needs to attain net zero emissions.