Carbon markets incentivize renewable energy, CCS, DAC, nature-based solutions and other CO2 offsets. In the past, we naïvely assumed these would grow as much as needed to reach Net Zero by 2050. This 14-page note revises our forecasts, by analogy to other forms of charitable giving. We see voluntary carbon markets reaching $400bn pa by 2050, while the EU ETS could be scaled back?