Extreme weather, such as the heavy rain that caused flooding along the Mississippi River, the tornados that ripped through the Midwest and South, and droughts in the West, all represent a “new normal” for which governments must plan, according to some scientists. Several cities and counties are heeding the dire forecast and laying plans to adapt infrastructure to accommodate more frequent and destructive storms.

During a May 18 teleconference sponsored by the Cambridge, Mass.-based Union of Concerned Scientists and the Washington-based ICLEI: Local Governments for Sustainability (ICLEI), climate scientists presented findings that the amount of moisture in the air is increasing, affecting the frequency and intensity of snow and rain throughout much of the country. “Calling it global warming is just a very, very small part of what we're seeing. What we're really seeing is 'global weirding,” said Katherine Hayhoe, climate scientist and research associate professor at Texas Tech University in Lubbock, Texas. “There's a lot going on today that is not what we are used to.”

While scientists cannot attribute any particular event specifically to climate change, Hayhoe says they do know that the background conditions against which regular weather patterns operate have changed. For example, Chicago, where Hayhoe has conducted several observations over the past few years, has had two “hundred-year storms” in three years.

Chicago officials are taking the forecast of increased extreme weather seriously and planning infrastructure improvements that can better channel large volumes of stormwater, says Aaron Durnbaugh, deputy commissioner for Natural Resources and Water Quality at the Chicago Department of Environment. Durnbaugh acknowledges that the forecasts are likely to change in the future as more information is gained, but he says that does not mean officials should postpone their adaptation plans. “We can't wait for the science to be 100 percent,” Durnbaugh says. “We need to act now. We need to prepare today with the best forecast information that we can have.”

Build it bigger

Along with large cities like Chicago, smaller cities like Lewes, Del., and Keene, N.H., are planning for more extreme weather, says ICLEI Climate Director Missy Stults. The best approach, she says, is to incorporate infrastructure modifications into regularly scheduled maintenance and improvement projects. For example, when Keene had to replace several culverts, the city expanded their width to accommodate greater stormwater levels. “If you can get in when you are already doing infrastructure updates, the cost is minimal, sometimes it doesn't even exist,” Stults says.

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