A bottom-up approach to climate mitigation for developing countries may have advantages over a top-down approach. Top-down approaches based on emission caps could incentivize setting overly high targets or delaying early action. They may also reduce predictability of emission levels and reductions compared to business-as-usual baselines. Bottom-up approaches like Nationally Appropriate Mitigation Actions strengthen domestic institutions in developing countries, which is important for successful low-carbon development programs but underemphasized in top-down approaches.