This top-scoring American city has been at the forefront of climate action for decades. San Francisco’s ambitious 2021 Climate Action Plan details how the city plans to reduce GHG emissions by 61% by 2030 and achieve net-zero by 2040. To reach its goals, San Francisco has implemented, and scored high on, numerous sustainable policies, including the phasing out of natural gas in new and significantly renovated buildings. San Francisco is also the highest-scoring city in the U.S. for efficient water consumption.