Study: Seattle area No. 6 on list of smallest carbon footprint

The West Coast's metropolitan areas, including Seattle, had among the lowest carbon emissions per capita in the country in 2005, according to a new ranking of 100 urban areas.

The region's mild climates, hydropower and aggressive energy-reduction policies give its residents smaller carbon footprints, on average, than those of their counterparts in the East and Midwest.

The Honolulu area, with the smallest carbon footprint, ranked No. 1 in the study, from the Brookings Institution, followed by the area including Los Angeles and Orange counties in California, the Portland-Vancouver area, the New York metropolitan area and the Boise-Nampa, Idaho, area.

The Seattle-Tacoma-Bellevue area ranked sixth.

A cluster of Rust Belt urban areas were at the bottom of the rankings, including Cincinnati, Indianapolis, Toledo, Ohio, and Lexington, Ky., which ranked last.

The authors offer a partial portrait of overall emissions, concentrating on residential electricity and fuel use and the mileage traveled by cars and trucks, factors that contribute about half of overall carbon emissions. The calculations do not include industrial emissions, those from commercial or government structures and those from air, rail or sea transportation.

The report was accompanied by policy recommendations, including federal legislation setting a price on carbon emissions, increasing financing for energy research and development, revising federal policies that reward states with high levels of travel and fuel use and providing more, and more predictable, financial support of mass transit.

While the report did not go into the precise causes of each ranking, it provided hints at factors that correlated with higher or lower scores. Population density and the availability of rail transportation were associated with lower per-capita carbon emissions; the Los Angeles area is the most densely populated in the country, according to Brookings figures.

Outside of the West Coast, metropolitan areas in the top 25 included Boston; Buffalo, N.Y., Chicago; New Haven, Conn.; Poughkeepsie, N.Y.; and Rochester, N.Y.

Also associated with high rankings were government policies that promoted energy efficiency, particularly electricity rate-setting policies.

Rate-setting by state regulators has traditionally been geared to make more money for a utility if it sells more electricity. While rates may remain relatively low, pleasing customers, utilities have little incentive to encourage energy conservation.

The Washington, D.C., metropolitan area ranked No. 100 in per-capita residential carbon emissions and No. 89 on the overall list.

"The Washington, D.C., metro area's residential electricity footprint was 10 times larger than Seattle's footprint in 2005," the report said. "The mix of fuels used to generate electricity in Washington includes high-carbon sources like coal while Seattle draws its energy primarily from essentially carbon-free hydropower."

California sets extensive energy-efficiency requirements for home appliances; per-capita energy use has remained largely flat in the state for 30 years. This factor, combined with its low-carbon electricity and warmer climate, is probably why eight of 10 California metropolitan areas made the top 25 on the Brookings list.

Among the report's recommendations was a change in federal law that would require home sellers to disclose the annual energy costs of the dwelling in the years before the sale.

The measurement system was created by three Brookings authors: Marilyn Brown, a professor of energy policy at the Georgia Institute of Technology; Frank Southworth, who is on the senior research staff at Oakridge National Laboratory; and Andrea Sarzynski, of the Brookings Institution.

Material from The Associated Press is included in this report.