The release last Thursday of a report by the Brookings Institution ranking the Seattle-Tacoma-Bellevue metropolitan area as the sixth lowest in the nation in terms of per capita carbon emissions comes at a time when Bellevue has been aggressively working to reduce its carbon footprint, officials say.

“The report is encouraging, but we should be careful not to read too much into it,” Bellevue Mayor Grant Degginger said. “It’s going to take a multitude of efforts over decades to achieve our ultimate goals.”

The report marks the first time carbon emissions from metropolitan areas have been studied. It measured carbon emissions in two areas – highway transportation and residential energy use – in 2000 and 2005.

Sheida Sahandy, who serves as lead for the city’s Environmental Stewardship efforts, noted the study sets forth only a partial carbon footprint because it does not account for emissions from the commercial building sector, industry or non-highway transportation, such as ships and air travel.

“It is a snapshot of two areas in two years,” Sahandy said. “Nevertheless, it is a great starting point to inform policy choices being made on the federal level.”

The report is an example of steps being taken to tie together local efforts to reduce man-made causes of climate change and gain a better understanding of the nation’s entire emissions picture. The United States Senate is currently considering legislation aimed at reducing greenhouse gas emissions in coming decades by allowing companies to trade, save or borrow emission allowances.

In Bellevue, the city’s ongoing greenhouse gas reductions efforts have included:

Adopting land use patterns that concentrate development density in the downtown area, which has been shown to reduce greenhouse gas emissions as compared to a more dispersed pattern of development.

Conducting a citywide tree canopy study to guide the preservation and enhancement of the city’s tree canopy.

The establishment of native growth protection areas as part of the city’s critical areas ordinance.

Adopting a transportation policy statement calling for increased mass transit systems to reduce dependency on single-occupancy vehicles.

Conducting a greenhouse gas emissions inventory in 2007 following adoption by the City Council of the U.S. Mayors Climate Protection Agreement. That inventory is being used to identify emissions reductions opportunities.

Educating the city’s development services staff on energy-efficient and environmentally friendly building practices.

Purchasing hybrid vehicles when feasible for the city fleet.

Electing to renovate and reuse an existing building as its new City Hall. The building is located next to the transit center, encouraging public transportation for staff and residents. In the renovation process, energy-saving measures were used that are expected to reduce carbon dioxide emissions by 638 metric tons by 2012, and to save city taxpayers between $60,000 and $70,000 a year in energy costs.

“It is a complex and long-term problem but, as the report shows, we are making progress and we are among those municipalities leading the way,” Degginger said. “That is pretty exciting.”