U.S. cities prepare to adapt to climate change

In Chula Vista, Calif., new waterfront buildings will be required to have higher foundations because of an expected rise in sea levels.

In Chicago, where flooding is predicted to worsen, residents can get rebates for putting rain barrels, compost bins and native plants in their yards.

And in New York City, where rising tides are also projected, wastewater treatment plants will elevate their pumps.

While some members of Congress debate the scientific validity of climate change, these U.S. cities are going beyond efforts to mitigate it with lower greenhouse gas emissions. They're at the forefront of an emerging trend: adaptation.

"It's a new field," says Brian Holland, director of climate programs at ICLEI-Local Governments for Sustainability USA. His association launched a Climate Resilient Communities program last year to help cities study effects of climate change and finance ways to adapt. Nearly 600 local governments, representing one-fourth of the U.S. population, have signed on.

As extreme weather continues to sweep the nation and Americans struggle to deal with heat waves and flooding, Holland says many are convinced they need to act. "We're already seeing consequences of climate change," he says, "and those will only intensify."

An increasing number of cities have begun vulnerability assessments, and some — notably Chicago — are already taking steps to counter adverse effects.

"We're mostly at the study and planning phase," says Michelle Mehta, co-author of the "Thirsty for Answers" report this month by the Natural Resources Defense Council (NRDC), which looks at how a dozen U.S. cities will be affected.

The NRDC report says coastal cities such as New York and San Francisco anticipate "serious challenges" from sea-level rise, while Southwestern cities such as Phoenix will face water shortages and Midwestern cities, including Chicago and St. Louis, can expect more intense storms and flooding.

Climate change skeptic David Kreutzer, a research fellow in energy economics at the conservative Heritage Foundation, says there have always been "variations in weather" so it makes sense to prepare for storms. But he says cities may waste money if their regulations are based on "hysterical" projections of sea-level rise.

Scott Huth, public works director for Coronado, Calif., a beach town of 25,000, says the planning is not about politics or being liberal or conservative, it's simply about taking seriously "our duty to make sure that we're informed for things that might potentially happen."

Mehta says some projects meet immediate needs but will also help cities cope with problems exacerbated by climate change. Among them are elevating homes and rebuilding levees in New Orleans, which is steadily sinking. Other projects are more tailored to climate change:

•Seattle has developed a climate tool, now being tested, that allows users to input variables such as the location and timing of a proposed project to learn how it will be affected.

•San Francisco plans next year to build devices in three locations to prevent salty bay water from overflowing into the city's combined storm-water and wastewater system. Rising sea levels already cause four to seven overflows each year that harm water treatment, says David Behar of the San Francisco Public Utilities Commission. "We expect a nuisance will become a problem," he says, adding: "Sea-level rise is inexorable."

•Chicago is planting trees and replacing impervious surfaces such as concrete sidewalks with permeable materials to allow rain to seep into the ground. It has more than 600 green roof projects completed or underway. "We're making the city resilient to climate changes right away," says Karen Weigert, the city's chief sustainability officer.

•Chula Vista, in San Diego County, approved a climate plan in May that calls for more shade trees and "cool" or reflective roofs. Citing a study that sea levels — already up 6 inches since 1900 — will rise 12 to 18 inches more in the next 40 years, it also requires that new waterfront projects account for this projected increase.

•Norfolk, Va., is doing a feasibility study on measures such as dam structures to deal with the area's 14.5-inch rise in sea level over the past 80 years — whatever the cause. "The city is trying to be as proactive as possible without engaging in the hyperbole of climate change arguments," says John White, the city's engineer for storm-water systems.

•New York City is not only planting a million trees, it also has a $1.5 billion, 20-year plan for green infrastructure to help manage storm-water runoff from increasingly powerful storms.

Financing such projects is a challenge now for local governments, but not all needed changes require extra cash, says David Bragdon, director of long-term planning and sustainability for New York City.

"It's altering the way we're doing things," he says. "It's building something to fit the likely conditions of the future."

Contributing: Elizabeth Weise