How Urbanism Slows Global Warming

Sure, hybrid cars and other energy-efficient vehicles are part of the solution to global warming and oil dependency, but how much people drive is as important as what people drive.

The separate-use zoning codes that shape sprawling exurban areas make it impossible to do anything but drive between all important destinations -- home, work, school, stores and cultural destinations. Compact urbanism brings many of those locations within walking distance and urban densities support high-quality transit service, giving people convenient lower-impact ways of getting around. Even better, New Urbanism makes these features part of environments recognized for their livability, desirability and sense of place. It's not about taking away people's right to drive; it's about them choosing to use their cars less by taking advantage of compelling urban places.

The LEED-ND Public Health Report compiles convincing evidence on urbanism's role in reducing greenhouse gas emissions from a series of leading studies. I'll provide highlights from that report (and other sources) in a future posting, but in the meantime, CNU has just posted a concise slide presentation on the relationship between climate change and transportation (and the role of urbanism as a remedy) from Hank Dittmar, the co-author of one of those leading studies.

The slide above (from Dittmar's slideshow) shows how dense cities are commonly viewed as areas of concentrated CO2 emissions (when emissions are viewed on a per-square-mile basis) but are actually extremely low producers of such emissions when viewed on a per capita (or per household) basis. Specifically, the average exurban household in a sprawling Chicago exurb generates about 11.5 tons of C02 per year, but those in suburban areas served by commuter rail generate 23% less C02 with their cars, or about 9 tons on average. By moving to a city neighborhood -- or a compact, mixed-use rail-connected suburb such as Evanston or Oak Park -- a household would expect to see their auto-generated C02 drop steeply toward about 2.5 tons per year. They'd be switching to transit for some trips, which involves some generation of greenhouse gases, but at a far, far reduced rate. And more destinations would be within walking and biking distance too. Take a closer look at the maps.

The difference is all in the efficiency with which people move around highly urbanized environments. Thanks to the Center for Neighborhood Technology, the original source of this revealing map.

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paytonc's picture

More education needed

A friend sent along these recent Gallup Poll results, from a poll taken Mar. 23-25:

Steps the Government Can Take to Reduce Global Warming (by party identification):
Democrats | Independents | Republicans (percentage saying "should be doing")
72 | 64 | 58 Starting major research effort to develop new energy sources
72 | 60 | 47 Requiring government office buildings to use renewable energy sources
59 | 43 | 36 Requiring surcharge on utility bills when energy use limits exceeded
59 | 44 | 26 Banning vehicles that do not average at least 30 miles per gallon
47 | 35 | 26 Setting land-use policies to discourage suburban sprawl
46 | 40 | 28 Imposing tough restrictions on U.S. industries and utilities

While Americans, especially Democrats and Independents, were quite enthusiastic about taking individual steps to combat global warming (over 75%, and over 80% of Dems and Inds, said they should be "spending thousands of dollars to make [my] home energy efficient" and "riding mass transit whenever possible"), they're much more wary of government "making these choices for them." Not even a majority of Democrats want to discourage sprawl, and Independents seem quite wary of government intervention.

I think that this means we should both focus on teaching people that urbanism means higher quality of life, wiser investment of scarce resources, and greater choices -- and saving the world, of course.

More on the "Convenient Remedy" at NRDC, including Atlanta maps

Kaid Benfield blogs at the NRDC website and joins John Norquist in touting urbanism and smart growth as convenient remedies to the Inconvenient Truth of global climate change.

Benfield's sharp posting includes dramatic new maps created by Eliot Allen of Criterion Partners, showing how much less driving people in Atlanta's walkable near-in neighborhoods do than those in Atlanta's exurbs -- as much as five times less.


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