A 'green' Rx to save carbon: city density plus transit.

Earth Day this year was a lot different from the first observance in 1970. Back then, we faced highly visible smog in the air, towns combating toxic waste sites, and a Cuyahoga River on fire.

Today's challenges are so much greater--biodiversity, species loss, melting polar caps, rising sea levels, longer droughts. And now a global food crisis triggered in part by our craze for corn-based ethanol to shake petroleum dependency. But human ingenuity is not yet extinct. And some basic truths require our careful attention.

For ingenuity, consider all the "green" planning that's under way in our communities, both the building of fancy new energy-efficient buildings and--perhaps even more important--rehabbing of buildings for greater energy efficiency, and thus fewer carbon emissions.

Because while we talk of the energy gobbled up by cars, trucks and airplanes, the fact is they account for just 27 percent of U.S. greenhouse gas emissions. Almost twice as much--48 percent--is produced by the construction and operation of buildings.

In several regions, major financial houses are developing ways to let office building owners upgrade to high energy efficiency savings with virtually zero upfront expenses. The costs (for new energy-saving furnaces, windows, insulation) are automatically paid through subsequent energy savings. All that's missing now is a parallel plan for homeowners.

Building energy upgrades offer our earliest, biggest chances to cut greenhouse gas emissions. And they produce another dividend: lots of blue collar jobs including electricians, carpenters, drywall contractors--the list goes on and on. And these are jobs that can't be shipped overseas.

Richard Moe, president of the National Trust for Historic Preservation, pulls us up short with an easily ignored fact: Instead of tearing down our older buildings for bigger or fancier replacements, we do a lot better, energy-wise, to rehabilitate and keep using them.

"Preservation is sustainability--buildings are vast repositories of energy," Moe argues. For a 50,000-square-foot building, he notes, the cost of teardown and replacement--hauling away tons of waste, re-excavating, manufacturing new construction materials, operating tools, installing lighting and heating and cooling systems--"embodies" the equivalent of 640,000 gallons of gasoline.

Moe asserts that even if a project includes 40 percent recycled materials, it takes about 65 years for a "green, energy-efficient office building" to recover the energy lost in demolishing and replacing an existing building.

What about that? I asked Jonathan Rose, a lead "green" community developer and chair of a sustainability commission created by New York's Metropolitan Transportation Authority. "In most cases," said Rose, "it's correct to save old buildings." But not always, he cautions: Higher density of offices and residences is necessary to support public transportation and reduce our gasoline consumption. "More accessibility," he asserts, "means higher density"--especially near transit.

So why is density so critical? Consider New York. With a robust, convenient subway/bus system, New Yorkers have per capita carbon dioxide emissions a quarter of the national average. Rose wants New York--and urban regions nationally--to go further, embracing the renewable energy sources and higher efficiencies to be "globally competitive and locally equitable." The U.S. is projected to have 90 million more people in the next 40 years, he notes, adding:

"If this growth is not clustered around green transit, we will not only overwhelm our climate, but also destroy much of our nation's biodiversity through suburban sprawl. Green mass transit is the key to a green future."

One has to think that a century ago, we were celebrating new streetcar and subway systems. Rose is insisting our new century's success depends on the same. For the New York region, for example, "We aspire to have 86 percent of all new trips generated by our population growth be generated by transit--trains, buses, mini-buses, plus bike paths and walkability."

The puzzle is affordability. Private markets should be able to finance energy efficiency steps for buildings. But big-scale public transit improvements and expansions, lifting our urban regions to world standards, will require public dollars--including a significant federal share. And there's the rub: Whether the proposed source is the Treasury or a future carbon "cap and trade" system, opponents are sure to cry "unaffordable."

But "unaffordable" compared to what? Check the clean energy advocacy group, Oil Change International (www. priceofoil.org/climateofwar/). It claims that the "projected total U.S. spending on the Iraq War" (assuming about $3 trillion) "could cover all of the global investments in renewable power generation needed between now and 2030 to halt current warming trends" (i.e., restraining global temperature increases to 2 degrees centigrade).

Translation: Without a massive war-to-peace transition, focused on serious climate-related investments, on Earth Days in decades to come we'll be mourning the more sustainable society we could have had.

Neal Peirce's e-mail address is nrp@citistates.com.

The opinions expressed in this column are not necessarily those of the National League of Cities or Nation's Cities Weekly.