NEWS

Few transportation choices create big carbon footprints

05/29/2008

Christa Marshall, ClimateWire reporter

The Lexington-Fayette region in Kentucky has the worst per capita carbon footprint of the nation’s 100 largest metropolitan centers, while Honolulu and car-dependent Los Angeles, surprisingly, fare the best, according to a new survey of urban emissions.

An area’s mass transit use, level of sprawl, freight traffic, electricity pricing and air conditioning and heating use all played major roles in determining how it ranks in the study from the Brookings Institution, a Washington, D.C., think tank.

The Mississippi River essentially divides the high and low carbon emitters, with nine of the 10 worst metro areas appearing in the East. The West was the only region to decrease its per capita carbon footprint from 2000 to 2005.

"We hope with this report we’re going to promote a competition for the climate and energy challenges we face," said Marilyn Brown, a study co-author and energy policy professor at the Georgia Institute of Technology.

But the study warns that results for any particular metropolitan area should be "treated with caution."

2005 Per Capita Carbon Footprints from Transportation and Residential Energy Use Varied Widely by Metro Area
Largest Carbon Footprints (out of 100 largest metro areas)	Smallest Carbon Footprints (out of 100 largest metro areas)
1. Lexington-Fayette, Ky.	1. Honolulu, Hawaii
2. Indianapolis, Ind.	2. Los Angeles-Long Beach- Santa Ana, Calif.
3. Cincinnati-Middletown, Ohio-Ky.-Ind.	3. Portland-Vancouver-Beaverton, Ore.-Wash.
4. Toledo, Ohio	4. New York-Northern New Jersey-Long Island, N.Y.-N.J.-Pa.
5. Louisville, Ky.-Ind.	5. Boise City-Nampa, Idaho
6. Nashville-Davidson-Murfreesboro, Tenn.	6. Seattle-Tacoma-Bellevue, Wash.
7. St. Louis, Mo.-Ill.	7. San Jose-Sunnyvale-Santa Clara, Calif.
8. Oklahoma City, Okla.	8. San Francisco-Oakland-Fremont, Calif.
9. Harrisburg-Carlisle, Pa.	9. El Paso, Texas
10. Knoxville, Tenn.	10. San Diego-Carlsbad-San Marcos, Calif.
Data courtesy of Blueprintprosperity.org.

The authors focused solely on residential energy use and vehicles using highways, leaving out emissions of commercial buildings, industry and non-highway transportation. That excludes about half of a metropolitan region’s carbon footprint, Brown said.

"Steelmakers and other industry can put a lot of greenhouse gases in the atmosphere, so this study only is a subset of the carbon picture," said Kevin Gurney, assistant professor of earth and atmospheric sciences at Purdue University and the director of the Vulcan Project, a federal government-supported map of carbon dioxide emissions. He did not participate in the Brookings survey.

Still, Vulcan’s numbers for Los Angeles County seemed similar to Brookings’ measurement of 1.41 metric tons of carbon per year for the Los Angeles-Long Beach-Santa Ana corridor when industry was factored out, he said.

The urban core of Los Angeles is dense, and there is probably misinformation about the city, Brown said, although she conceded that the study did not include commuters from some counties surrounding the city.

To calculate a city’s listing, the Brookings researchers gathered traffic data from the U.S. Department of Transportation and obtained electricity sales information from Platts Analytics.

The average resident of Lexington, Ky., emitted about two and a half times more carbon from transport and homes in 2005 than the average resident of Honolulu, according to the report. Indianapolis; the Cincinnati-Middletown area of Ohio, Kentucky and Indiana; and Toledo, Ohio, followed Lexington in carbon emissions.

Economic strengths create environmental weaknesses

The high emitters "tend to be in areas with few transportation choices," said Andrea Sarzynski, a senior research analyst in Brookings’ Metropolitan Policy Program. "They don’t allow for biking, walking and mass transit."

Location along major freight corridors didn’t help many urban areas, as 24 percent of carbon emitted on highways in the 100 largest metropolitan centers comes from freight trucks, Sarzynski said. Weather also came into play for cities that depend on heating and air conditioning excessively, particularly if their fuel sources were fossil fuels, she said.

Lexington has taken proactive steps in the past six months to reduce its carbon footprint by increasing funding for alternative transportation, said Cheryl Taylor, the city’s commissioner of environmental quality, a position created last year.

"Like many cities, our economic strengths create environmental weaknesses," Taylor said. "Our proximity to the eastern coalfields has provided us with some of the nation’s lowest electrical costs."

Those low costs are a problem for carbon output because they discourage changes in behavior, the report argues. The 10 cities with the lowest per capita electricity consumption were in states with higher than average electricity prices.

Many states and localities have passed their own climate initiatives in recent years, but the study’s authors argued that the government needs to do much more.

In particular, they urged lawmakers on Capitol Hill to put a price on carbon, pass a national renewable electricity standard, invest in research and development and help states reform electricity regulations so utilities are rewarded for efficiency.

And there is good news for the 100 largest urban areas, which house two-thirds of the nation’s population, particularly in comparison to more rural parts of the country that often have less mass transit.

"The carbon footprint of someone living in a large metro area is 14 percent smaller than the average American’s, and in recent years, has expanded by only half as much," the report says.