Approaches that root national climate strategies in local actions will be essential for all countries as they develop new nationally determined contributions under the Paris Agreement. The potential impact of climate action from non-national actors in delivering higher global ambition is significant. Sub-national action in the United States provides a test for how such actions can accelerate emissions reductions. We aggregated U.S. state, city, and business commitments within an integrated assessment model to assess how a national climate strategy can be built upon non-state actions. We find that existing commitments alone could reduce emissions 25% below 2005 levels by 2030, and that enhancing actions by these actors could reduce emissions up to 37%. We show how these actions can provide a stepped-up basis for additional federal action to reduce emissions by 49%—consistent with 1.5 °C. Our analysis demonstrates sub-national actions can lead to substantial reductions and support increased national action.

对于所有国家来说，将国家气候战略植根于地方行动的方法对于所有国家来说都是至关重要的，因为它们根据《巴黎协定》制定了新的国家自主贡献。非国家行为者采取气候行动对实现更高的全球雄心可能产生巨大影响。美国的地方行动为此类行动如何加速减排提供了标准。我们在一个综合评估模型中汇总了美国的州，市和商业承诺，以评估如何根据非州行动制定国家气候战略。我们发现，到2030年，仅现有的承诺就可以将排放量比2005年的水平减少25％，而加强这些行为者的行动可以将排放量减少多达37％。我们将展示这些行动如何为进一步的联邦行动提供基础，以将排放量减少49％（与1.5°C一致）。我们的分析表明，地方行动可以导致大量减少，并支持增加国家行动。