About four in 10 American cities are seeing a reduction in air pollution, according to an April report by the U.S. Conference of Mayors.
The report shows how an environmental campaign launched almost a decade ago has taken root in cities across the country. Its findings suggest that local political leaders are taking steps to curb greenhouse gas emissions created by their own government operations and the community at large. The report also leaves room for future research on how cities track the emissions, how much the average city has cut emissions and which local practices have the largest impact.
The findings come from a survey of the nation's mayors conducted between November 2013 and January 2014. Nearly 1,400 mayors, mostly from cities with at least 30,000 residents, received an emailed survey. Of those, 282 mayors responded. The population size of cities represented in the survey varied widely, from places as small as Pharr, Texas (about 73,000) to the some of the largest urban centers in the country, such as Los Angeles (about 3.9 million).
A majority of respondents (149 cities) said they had taken a public action -- in the form of a mayoral pledge, a formal city council vote, or both -- to reduce greenhouse gas emissions.
In cities that made a public commitment, 71 percent said they had recorded a drop in emissions caused by city government operations, the community at large, or both. Because of the way the survey was written, the results exclude cities that saw a reduction in emissions but did not take a public action, leading the report's authors to conclude that in all likelihood more cities are cutting emissions than what the survey found.
About 48 percent of mayors said they had conducted some kind of inventory of greenhouse gas emissions, either of city operations, the community at large, or both. The report does not explain how cities conducted those inventories or whether they measured emissions in comparable ways.
The report also highlights some strategies employed by mayors who are trying to reduce emissions. For example, some mayors said they asked citizens and businesses to take voluntary steps to curb their own emissions. They also listed promising technologies they've used, such as energy-efficient lights and solar electricity.
The report on reduced emissions is the third in a series about energy efficiency and the environment released in 2014 by the mayors group. Next year is the 10-year anniversary of a voluntary initiative launched by the mayors group to curb local greenhouse gas emissions in cities across the country. The group’s Climate Protection Agreement included three specific provisions:
Set city-specific targets to reduce local greenhouse gas emissions and take steps, such as increasing the use of alternative energy and expanding bike lanes, to reach those targets; Urge states and the federal government to to enact policies and programs that would reduce national greenhouse gas emissions to 7 percent below their 1990 levels; Urge Congress to enact a law that would limit greenhouse gas emissions and allow businesses to buy credits if they want to exceed their cap, more commonly known as cap and trade. The mayors group launched the voluntary campaign after then-President George W. Bush decided in 2005 not to sign the Kyoto Protocol, an international agreement between more than 140 countries to reduce greenhouse gas emissions. More than 90 percent of mayors from American cities with at least 30,000 residents -- or 1,060 mayors -- have signed the Climate Protection Agreement.
A pair of mayors from opposite political parties oversaw the most recent climate change report, Carmel, Indiana, Mayor Jim Brainard (a Republican) and Bridgeport, Conn., Mayor Bill Finch (a Democrat). They also co-chair the task force on energy independence and climate protection for the mayors group.
“As we all know, there are some, for political or other purposes, who try to make this a divisive issue,” Brainard said on a press call April 22. “In our cities and among mayors, however, it is unifying because we are saving our taxpayers money when we become more energy efficient.”
Greenhouse gas emissions in the United States increased by 4.7 percent between 1990 and 2012, though the country did experience several year-over-year decreases since 2005, according to the Environmental Protection Agency. To the extent that emissions have gone down in any given year, the agency credited several factors that are not the result of municipal policy, such as increased fuel prices, increased coal prices and moderate seasonal weather (cool summers or warm winters) that resulted in less home energy use. Also, some major sources of emissions, such as agriculture, are largely outside mayors' scope of influence. It remains to be seen whether the aggregate effect of policies being enacted by cities can make a significant dent in national emissions.