US cities in front line as sea levels rise

Deborah Zabarenko in Reuters: The signs of rising water are everywhere in this seaport city: yellow "Streets May Flood" notices are common at highway underpasses, in low-lying neighborhoods and along the sprawling waterfront. Built at sea level on reclaimed wetland, Norfolk has faced floods throughout its 400-year history. But as the Atlantic Ocean warms and expands, and parts of the city subside, higher tides and fiercer storms seem to hit harder than they used to.

Dealing with this increased threat has put Norfolk at the forefront of American cities taking the lead on coping with intense weather, from floods to droughts to killer heat, without waiting for the federal government to take the lead.

In Norfolk, home to the largest U.S. Naval base and the second biggest commercial port on the U.S. Atlantic coast, floods are a perennial problem that has worsened in recent decades, Assistant City Manager Ron Williams Jr told Reuters.

The relative sea level around Norfolk has risen 14.5 inches (.37 meter) since 1930, when the low-lying downtown area routinely flooded. The floods are worse now, because the water doesn't have to rise as high to send the river above its banks and into the streets, Williams said. At the same time, severe storms are more frequent. "We've had more major storms in the past decade than we've had in the previous four decades," he said. Extreme rainfall events have increased too.

Williams does not call what's happening in Norfolk a symptom of climate change. "The debate about causality we're not going to get into," he said. Still, many scientists see the frequent flooding as consistent with projected consequences of rising global temperatures, spurred by increased emissions of greenhouse gases.

No matter what city leaders call it, some of their actions speak louder than words. Williams said Norfolk, a city of 243,000, needs a total investment of $1 billion in the coming decades, including $600 million to replace current infrastructure, to keep the water in its place and help make homes and businesses more resilient....

The USS Harry S. Truman heads up the Elizabeth River as it passes the downtown Norfolk waterfront, US Navy photo by Mass Communication Specialist 3rd Class Tyler Folnsbee/Released