The White House has applauded Portland, Ore., and 15 other local governments as “climate action champions” for promising to reduce greenhouse gas emissions. Perhaps the White House should have waited to see whether any of the communities managed to meet their goals before patting them on the back.

Portland’s “modest” goal is to reduce the city and Multnomah County emissions by 80 percent from 1990 levels by 2050. Planners claim that, as of 2010, the city and county had reduced emissions by 6 percent from 1990 levels. However, this claim is full of hot air as all of the reductions are due to causes beyond planners’ control.

Almost two‐​thirds of the reduction was in the industrial sector, and virtually all of that was due to the closure in 2000 of an aluminum plant that once employed 520 people. The closure of that plant hasn’t led anyone to use less aluminum, so all it did was move emissions elsewhere.

Another 22 percent of the reduction was in residential emissions, and that was due solely to 2010’s “anomalously mild winter” and below‐​average summer temperatures, as 2009 emissions were greater than those in 1990. Only 7 percent of the reduction was in the transportation sector, for which Portland is famous. But all of that reduction was due to the recession, not the city’s climate plan, as transport‐​related emissions grew through 2005 and the city didn’t record a reduction until 2009.

Portland doesn’t have many more large factories that it can put out of business to achieve its climate goals. Nor can the city count on a continued economic depression to keep people from driving or an anomalously mild climate to keep people from turning on their heat or air conditioning.

The lesson here is that cities and counties are the wrong level to try to reduce emissions of something like greenhouse gases. This is a lesson we should have learned already based on our experience with toxic pollutants such as carbon monoxide and nitrogen oxides.

In 1970, Congress required urban areas with dirty air to write transportation plans that aimed to reduce air pollution. Since then, total tons of transport‐​related air pollution (carbon monoxide, nitrous oxides, sulfur dioxide, volatile organic compounds, lead, and particulates) have declined by 83 percent—and all of that decline came from making cleaner cars. If anything, too many regional transportation plans have made air dirtier by focusing on trying to get people out of their cars and using increased congestion as a tool for doing so. Cars pollute more in traffic congestion, but planners didn’t built that into their models, so they could claim that their plans would work when they actually didn’t.

Despite this failed record of trying to reduce air emissions at the city and county level, the White House is very grateful to Portland and other local governments for writing greenhouse gas reduction plans that make promises they won’t be able to keep. They will, however, be able to use those plans to increase transportation, housing, and other consumer costs. The cities consider that a small price to pay to be declared a climate action champion.