Increasingly there appears to be recognition of the need to simultaneously implement adaptation and mitigation. However, the optimal combination of adaptation and mitigation is an open question. The literature on this is rather small, and is inconsistent in conclusions. Here we explore the temporal optimal investment mix between adaptation and mitigation and their relative contributions to damage reduction. We do this using a conceptual framework that integrates mitigation and adaptation considering one time flow and persistent stock adaptation. We also consider unadaptable damages and investment competition. Results suggest that stock and flow adaptation are dominant damage reduction means in the first 120 years while mitigation dominates from thereon. We also find that the adaptation/mitigation mix changes markedly toward mitigation when climate change damages per unit atmospheric CO 2 concentration rises.