Warming could worsen many problems along coast

Louisiana's coastal parishes and other Gulf communities from Houston to Mobile should build higher and more resilient roads, bridges and other infrastructure to withstand more intense hurricanes and rainstorms, sea level rise and higher temperatures caused by global warming during the next 50 to 100 years, according to a draft report prepared by the federal Department of Transportation and the U.S. Geological Survey. But Louisiana, largely in response to Hurricanes Katrina and Rita in 2005, may be ahead of other states. Transportation and hurricane-protection planners in Baton Rouge are already responding to concerns raised in the report, forging ahead with heat-resistant pavements and higher bridges and levees.

Elsewhere along the coast, transportation planners are only now considering the effects of climate change in the next 100 years, which could include as much as a 4-foot rise in sea level, a 10 percent increase in the intensity of hurricanes, a dramatic increase in the number of days with temperatures of 90 and 100 degrees or higher, and more periods of intense rainfall.

At risk are thousands of miles of roads, hundreds of bridges and dozens of airports that will be flooded more often or could be damaged by periods of high heat or more frequent hurricanes, or whose operations could otherwise be affected by climate changes, according to the report.

The report concludes that the combination of more intense hurricanes and higher sea levels also will expand the area facing potential storm damage, a concern because existing roadway capacity is not designed for large-scale evacuations.

"This preliminary assessment raises clear cause for concern regarding the vulnerability of transportation infrastructure and services in the central Gulf Coast due to climate and coastal changes," the report concludes.

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