Driving Down Climate Change

Greenhouse gases from transportation are a major contributor to climate change. State officials estimate that as much as 38 percent of carbon dioxide emissions in Oregon come from tailpipes. Reducing petroleum-based greenhouse gases is just as important to limiting climate change as are renewable energy development, more energy efficient buildings and appliances, and changes in manufacturing.

Oregon has a strategy for reducing transportation greenhouse gases, and the legislature has given Metro a leading role in carrying it out. A 2009 state law directs Metro, over the next two years, to engage local governments and the public to find ways to make it possible for us to drive less as the region grows—enough less that carbon dioxide and other atmospheric pollutants from tailpipes drop to less than half their 1990 levels by 2035.

The state is banking a lot on technology to help us get there. Researchers from a group of state agencies believe that Oregonians will buy far more hybrid and all-electric cars in future years; that we’ll buy fewer pickups, vans, and SUVs; and that we will buy new cars more frequently, speeding the conversion of the private-vehicle fleet to a much more efficient, low-polluting mix of cars and light trucks.

In fact, the state predicts that these technological improvements will get Oregon 80 percent of the way to its 2035 greenhouse gas reduction goal for transportation. It’s the last 20 percent reduction in greenhouse gases that Metro’s strategies—a mixture of land use and transportation policies and investments—are expected to deliver for our region.

Metro calls its state-mandated (and funded) planning process “Climate Smart Communities.” Its overall goal is pretty basic: reduce regional driving enough to cut greenhouse gases another 20 percent by 2035. According to state agency estimates, that means the region will have room for about a 22 percent increase in total miles driven over the next 30 years—while our population is expected to grow by 42 percent during that time.  As a result, Portlanders in 2035 will need to drive about 14 percent less than we do today.

There’s actually nothing new about Americans driving less. As I wrote a few weeks back, our region is a leader in an international trend of less driving per person in developed nations. While there’s a lot of speculation about the reasons for this decline in driving, it’s unmistakable here in Oregon, where total driving in 2009 was about the same as in 1999—despite the addition of about 400,000 new residents during that time period. If this trend continues, our region will more easily be able to achieve its transportation climate change mitigation goals.

But the focus of Climate Smart Communities is not on forcing people out of cars. It’s on expanding opportunities for transit, biking, and walking—and on creating the kinds of neighborhood environments that make those transportation choices safe, convenient and enjoyable. Fundamentally, this means shifting new public investment to follow the emerging preferences of our region’s residents: away from expanding roads and expanding the urban growth boundary, and toward focusing growth in town centers and along main streets, and spending transportation dollars to make transit, walking, biking, and shorter driving trips more convenient and safe. 

As we look at the “climate smart” land use and transportation scenarios that Metro planners will share with the public in the months ahead, we should remember to follow the trend toward less reliance on the car—not to fight it. Every expansion of the urban growth boundary will create more driving trips, for longer distances, than development of jobs and housing within our communities. Every expansion of roadways will—temporarily, at least—make it more convenient to drive to more distant shopping or services rather than do business closer to home. Both types of expansion would cost public dollars that should be spent on improved transportation and amenities to serve our existing neighborhoods, and to help drive down the impact of transportation on global warming.