More than a year after the Trump Administration withdrew from the Paris climate agreement, cities and states are continuing efforts to meet U.S. climate goals to reduce carbon emissions 26% by 2025. In a recent move, the U.S. Conference of Mayors unanimously approved a resolution during its annual meeting in support of the latest International Energy Conservation Code.

它说：“美国市长会议认识到城市共同努力的独特机会，以达到巴黎协定目标的占主导地位。”本月，一份新报告将量化此类措施的影响。The analysis, from the group America’s Pledge—led by California Gov. Jerry Brown (D) and former New York City mayor Michael Bloomberg (R)—is set to be released at the Sept. 12-14 Global Climate Action Summit in San Francisco.

The report, a “bottom-up climate action quantitative analysis,” will examine reductions achieved outside of federal action. Among other things, the report will focus on building energy efficiency and the impact of building retrofits.

该集团的数据显示，商业和住宅建筑目前占美国排放量的28％。美国承诺说：“各州控制着许多最强大的气候政策杠杆，从可再生投资组合标准到空气污染法规。”

To reduce emissions, cities are first tackling energy usage. The latest version of the International Energy Conservation Code (IECC), adopted by the mayors in June, largely maintains similar efficiency standards as the previous code, according to the Natural Resources Defense Council. Still, overall, the IECC has cut CO2 emissions by 36 million metric tons and cut costs by $44 billion over its 20-year existence, according to the Energy Dept. The code is expected to reduce CO2 emissions by 841 million metric tons from 2010 through 2040.

到目前为止，采用2018年代码更新的唯一管辖权是美国维尔京群岛。

Cities may choose to stick with the earlier versions of the code. Zach Baumer, climate program manager for Austin, Texas, says the city uses the 2015 IECC with amendments that make it tougher. “I think a lot of the focus has been on the new code because we have so many new buildings, there’s so much growth and construction happening in our city,” he says.

But cities are using other tools as well to tackle emissions, with a focus on buildings. “If you break down the way we look at reducing carbon emissions, we’re going to look at the biggest chunk first, and about 70-72% of our emissions come from buildings,” says Sandra Henry, Chicago’s chief sustainability officer.

明年，芝加哥将通过建筑物的评级系统扩展2014年的基准法令。城市能源项目高级城市顾问艾米·珠宝（Amy Jewel）表示，每栋建筑物将被分配一个能源绩效评级，该评级将分享。类似的计划将于2020年在纽约市启动。

For cities that set benchmarks or track consumption, “we’ve seen a trend of year-over-year reductions in energy use from 1% to 3% and often even more for carbon emissions,” says Kimi Narita, acting director, City Energy Project at NRDC.

Chicago has taken on retrofits as well, and its voluntary Retrofit Chicago program has 89 participating properties covering more than 56 million sq ft. The program and benchmarking projects together have produced a 1-2% average annual reduction in energy consumption, and the city has reduced emissions in the buildings sector by 17%.