A number of U.S. states have begun to use transportation and land-use policies and projects to reduce greenhouse gas (GHG) emissions in an effort to combat climate change. California's climate change program is among the most ambitious overall, but other states have made at least a small start.

Connecticut, Massachusetts, New York, Oregon, and Washington may well take the top honors, judging by a national survey that found nearly 600 state-level programs that could cut GHG emissions in the areas of climate, energy, transportation, and building. Boos and hisses might greet such states as Alabama, Mississippi, Nebraska, South Dakota, and Tennessee, which, based on the survey, appear to be nearly oblivious to or decidedly uninterested in these issues.

States Target Vehicles, Suburban Sprawl

Transportation policies and projects that aim to reduce greenhouse gas emissions generally fit into two categories: reductions in vehicle miles traveled (VMT) and metro-oriented development, according to Judy Greenwald, vice president of innovative solutions at the Pew Center on Global Climate Change in Arlington, Va., which conducted the survey.

In addition to California, 38 states have mandates or incentives to promote the use of biofuels and 18 states have vehicle GHG emissions standards, according to the survey. An important distinction with respect to VMT programs is that some aim to cut the total number of miles traveled while others focus on slowing the rate of growth of miles traveled.

Two examples of state-level VMT policies listed in the survey were:

• The New York State Energy Plan, established by an executive order in April 2008, called for an assessment of transportation measures to address energy, environmental, and health concerns.
• The Washington state Department of Ecology published a report that recommended strategies to reduce VMT and has been directed to adopt statewide goals to cut per capita VMT in three stages through 2050.

Projects May Reduce Emissions as Byproduct

A 20-page report, "Real Transportation Solutions for Greenhouse Gas Emissions Reductions," by the American Association of State Highway and Transportation Officials cites three examples of state highway projects designed to alleviate traffic congestion as a way to reduce emissions:

• The Dulles Corridor Metrorail Project will add a 23-mile rail line from Arlington County, Va., to Washington Dulles International Airport. The project, scheduled to be completed in 2016, envisions no-transfer Metrorail rides from Washington, D.C., to several major employment and shopping centers in the region and the airport.
• The Legacy Parkway Project in Utah was designed as a 14-mile four-lane highway for commuters in the Salt Lake City metropolitan area. The first phase opened in September 2008.
• The West Dodge Expressway in Nebraska comprises two elevated expressway bridges that were designed to ease traffic through Omaha's busiest highway intersection. The project opened in July 2006.

That these projects were cited in this report demonstrates a challenge researchers face in the effort to catalog transportation and land-use projects and policies that may cut emissions: Many state policies and projects combat climate change indirectly and inadvertently, not necessarily as their prime directive. A smaller scale example of this challenge is a plan adopted in Lancaster County, Pa., to protect farmland, but that also "had the effect of containing sprawl to higher density areas," explains Tara Ursell, communications associate at the Pew Center on Global Climate Change.

States Adopt Climate-Friendly Building Codes

Most states also have adopted new building codes for new state and residential buildings as a way to reduce emissions through land-use policy, according to a map created by the Pew Center.

Two dozen states require new state buildings to meet the Leadership in Energy and Environmental Design (LEED) standard (or equivalent). This standard, promulgated by the U.S. Green Building Council, awards points to buildings based on green-building criteria that include water conservation, energy efficiency, selection of building materials, indoor air quality, sustainable site development and innovation in building design, according to Ashley Katz, a spokesperson for the council in Washington, D.C.

Whether the LEED and other green-building standards reduce GHG emissions is an open question, however. Indeed, some critics have pointed out that LEED-compliant buildings aren't always energy efficient, according to a recent New York Times article.

States Order Cities to Study Emissions

Metro-oriented development seeks to locate jobs and other services closer to where people already are. (The term "smart growth," which generally refers to higher density, mixed-use, and infill development, has fallen out of favor, Greenwald suggests.)

Seventeen states have established some type of metro-oriented development policy, according to the survey. But many of these policies merely order studies or require local-level agencies to consider open space and reduction of emissions in their own land-use planning efforts, rather than mandate specific state-level actions. An exception is the Urban Transit Hub Tax Credit Act in New Jersey, which offers state tax credits to businesses that invest in a facility located within a half-mile of a rail station. This program is limited to businesses that have at least 250 employees and invest $75 million or more in the facility.

The Four Biggest LEED-Compliant Government Buildings

• California Department of Education: 421,150-square-feet; Sacramento, Calif.
• Arizona Biodesign Institute:175,860-square-feet,Tempe, Ariz.
• Newark Center for Health Sciences: 128,000-square-feet,Newark, N.J.
• Lewis and Clark State Office Building:120,000-square-feet,Jefferson City, Mo.

Source: U.S. Green Building Council

The Newark building is unique on this list because it was built on a brownfield while the others were built on previously developed sites. The council doesn't track cost data for LEED-compliant buildings.

California Is a Trend Setter

California has one of the most ambitious programs to reduce GHG: the state's goal is to get 33 percent of its electrical power from renewable energy sources by 2020.

Governor Arnold Schwarzenegger recently signed an executive order that directed the California Air Resources Board (CARB) to adopt regulations designed to achieve that goal. The order set July 31, 2010, as the deadline for the agency to adopt the regulations.

More than 20 other states also have targets to reduce GHG emissions.