Washington scored 68.76 , with a ranking of third for transportation and eighth for lifestyle and policy . It comes in ninth for environment and 29th for energy sources . Dedicated team Sustainable DC are working toward the Sustainable DC plan , which aims to make the District of Columbia the ‘ healthiest , greenest and most liveable city in the United States ’ by 2032 . Some of these targets include developing three times as many district-based businesses , cutting citywide obesity by 50 %, reaching out to at least 50 % of children in the district to educate them about sustainability , and to reduce the city ’ s greenhouse gas emissions by 50 %. 30 October 2017