Planners encouraged to consider climate change

AMHERST, Mass.—If the coming century continues to unfold as the “age of climate change,” it’s clear to University of Massachusetts Amherst land use planner Elisabeth Hamin and colleagues that cities and towns should begin now to assess such predicted impacts as warmer winters, more severe storms, and more intense rainfall. Because if we’ve learned only one lesson already, she said, it’s that we’re going to be surprised by what’s to come.

Hamin recently completed a study with colleagues in Australia that was designed to help community leaders of 68 fast-growing, medium-sized coastal towns there figure out how to plan for the sometimes drastic changes being predicted. For example, she said, some housing developments just getting underway are predicted to be under water in 10 years.

“Their experience is absolutely relevant for us here in the United States,” Hamin said, “because we’re just coming out of a long period when we’ve built very little infrastructure. We need new roads, bridges, storm drains and transit systems. And it looks like the new administration will move ahead with at least some new projects. Based on our findings, what we suggest is, let’s start thinking ahead.”

Her report suggests that rather than design infrastructure with past extremes in mind—once accepted as common practice—towns and cities must switch gears and begin to plan for conditions that fit predictions for the next 100 years, Hamin stressed. Much of the motivation for the Planning for Climate Change Report she wrote with colleagues at the University of Sydney came from mayors who saw what happened in New Orleans after Hurricane Katrina and asked themselves, “Could it happen here?”

Hamin and her co-authors say their study for the Sea Change Task Force also confirmed that “not everyone will be affected in the same way.” For example, older residents are less able than younger ones to adapt or move out of harm’s way, even when given plenty of warning. And the poor don’t have the money, a personal car, or other resources to relocate at all.

Hamin and a UMass Amherst colleague Craig Nicolson, research assistant professor of natural resources conservation, are now collaborating on a project that will assist New England towns in understanding how physical and social vulnerabilities might combine to create challenges related to climate change.

They suggest, among other things, that carefully crafted zoning rules might help everyone from village councils to county boards sidestep problems and guide development to not only save taxpayer’s money but also reduce risk to home buyers’ and developers’ investments.

Until recently, even if mayors and planning commission members wanted to see climate change predictions for their towns, they couldn’t do so easily, according to Nicolson. That’s because past global climate change models divided the earth’s surface into grids hundreds of miles across, larger than some New England states. But now, more useful details on a smaller scale are becoming available.

“In the last five to eight years, experts have been downscaling the global grid data to provide predictions useful on a more local level,” Nicolson said. The new tools include a Northeast Climate Impacts Assessment study by the Union of Concerned Scientists issued in 2007. Nearby Keene, N.H., is one of the few small cities in the United States to have used its conclusions in planning for the future, Hamin said.

Even though cities and towns may not have exact numbers, the UMass Amherst researchers point out, a range can help to identify best- and worst-case seasonal flood extreme scenarios. “You can predict that we’re going to need to build a whole lot of new culverts and bridges to handle more rainfall,” suggested Nicolson. Even better, from Hamin’s point of view, is that looking ahead may give towns more tools and encouragement to deal with managing higher stormwater levels using green techniques that emphasize handling flow on site, with low-impact, environmentally responsive methods.

Overall, Nicolson said, “These kinds of things can now be anticipated. We can prevent some of the most awful surprises by looking ahead instead of backward in time. We can start to answer the question of how we deal with what’s likely to come.”

The Union of Concerned Scientists’ climate change assessment is available online at www.climatechoices.org/assets/documents/climatechoices/NECIA_climate_report_final.pdf.