More dense, pedestrian-friendly development produces fewer GHGsThe House passed their climate change bill last spring, and the Senate Environmental and Public Works (EPW) Committee passed their version last week. It now moves on to the Finance Committee and perhaps Agriculture. It will be well into next year by the time the bill gets to the Senate floor.

The House and EPW versions have one major thing in common: They focus nearly all attention on reducing green house gases (GHGs) from the supply of energy. Through renewables, carbon sequestration, and a host of other supply-side measures, these bills hope to achieve the goal of 80 percent reduction in U.S. GHG emissions by 2050.

However, these bills are ignoring the demand side of the equation. Most research shows that the U.S. will not meet this ambitious goal without both the supply and demand measures. The demand side focuses on changing the built environment.

The built environment is both buildings and the transportation needed to get between them. Our buildings account for over 40 percent of energy usage and GHG emissions. The transportation system, largely fossil fueled cars and trucks, is responsible for about 30 percent. At approximately 70 percent, the built environment is the largest category of energy consumption and GHG emissions.

We now know that walkable urban development--where most daily trips from home can be made by walking, bike, or transit and where houses unintentionally shares their heat with the next door neighbor--uses far less energy and emits far less GHGs than the conventional drivable sub-urban household. Drivable suburban households are dependent on their cars for nearly all trips from a house with all sides exposed to the elements. Research shows that these urban households use and emit one- to two-thirds of the energy and GHGs of a car-dependent suburban household. The Urban Land Institute estimates, following three studies, that transportation-only GHG emissions reduction from walkable urban development could reduce total GHG emissions by 10 to 20 percent by 2050 alone.

We need policy that promotes demand-mitigation measures so more Americans will use less energy and emit less GHGs by where and how they live, work, and recreate. The fact that there is pent-up market demand for low GHG-emitting pedestrian-friendly urban development makes this a relatively easy policy for consumers to accept to boot.