Rising Seas: Coastal flooding already here

Rising sea level already lapping at the coasts

Rising sea level due to climate change is not some far off effect. It's already a reality for coastal communities.

If you missed Climate Cast this week I highly encourage you to listen to my discussion with Kerri and Justin Gillis from the New York Times.

Here's Justin's piece on how rising sea level due to climate change are a reality now on the coasts.

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NORFOLK, Va. — Huge vertical rulers are sprouting beside low spots in the streets here, so people can judge if the tidal floods that increasingly inundate their roads are too deep to drive through.

Five hundred miles down the Atlantic Coast, the only road to Tybee Island, Ga., is disappearing beneath the sea several times a year, cutting the town off from the mainland.

And another 500 miles on, in Fort Lauderdale, Fla., increased tidal flooding is forcing the city to spend millions fixing battered roads and drains — and, at times, to send out giant vacuum trucks to suck saltwater off the streets.

For decades, as the global warming created by human emissions caused land ice to melt and ocean water to expand, scientists warned that the accelerating rise of the sea would eventually imperil the United States’ coastline.

Now, those warnings are no longer theoretical: The inundation of the coast has begun. The sea has crept up to the point that a high tide and a brisk wind are all it takes to send water pouring into streets and homes.

Federal scientists have documented a sharp jump in this nuisance flooding — often called “sunny-day flooding” — along both the East Coast and the Gulf Coast in recent years. The sea is now so near the brim in many places that they believe the problem is likely to worsen quickly. Shifts in the Pacific Ocean mean that the West Coast, partly spared over the past two decades, may be hit hard, too.

These tidal floods are often just a foot or two deep, but they can stop traffic, swamp basements, damage cars, kill lawns and forests, and poison wells with salt. Moreover, the high seas interfere with the drainage of storm water.

In coastal regions, that compounds the damage from the increasingly heavy rains plaguing the country, like those that recently caused extensive flooding in Louisiana. Scientists say these rains are also a consequence of human greenhouse emissions.

“Once impacts become noticeable, they’re going to be upon you quickly,” said William V. Sweet, a scientist with the National Oceanic and Atmospheric Administration in Silver Spring, Md., who is among the leaders in research on coastal inundation. “It’s not a hundred years off — it’s now.”

Louisiana floods directly liked to climate chnage.

How will climate change most likely affect you? It's increasingly clear that a warmer with higher water content atmosphere is producing more frequent mega-rains. A new attribution study shows that the devastating Louisiana floods were probably 40% to 50% more likely due to human-induced climate change.

Climate Central elaborates.

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Climate change played a heavy role in the nightmarish storm that brought a three-day deluge to coastal Louisiana last month, triggering floods that killed 13 and left thousands more homeless, research released Wednesday showed.

The unprecedented 1 to 2 feet of rain that fell over parts of Baton Rouge and nearby communities over several days in the middle of August stunned experts. While such deluges are rare, the new research indicated that the likelihood the region will experience them may have doubled during the past century.

“This is a storm that’s going to be studied for years to come,” said Barry Keim, the Louisiana state climatologist and a professor at Louisiana State University. He was not involved with the study, which was published as a discussion paper Wednesday before being peer reviewed.

The findings were consistent with the general principle that global warming caused by greenhouse gas pollution from energy, farming and deforestation is increasing the risk and intensity of heavy storms worldwide.

The stubbornly slow-moving storm dumped more rain over the flood-prone region than its flood infrastructure could handle. At least one city, Central, home to 30,000 residents and 9,000 buildings that were flooded, is working to help property owners rebuild as quickly as possible, despite the rising risks that such floods could happen again.

“The odds of an event like this have increased over the past 100 years by at least 40 percent — and most likely a doubling,” said Karin van der Wiel, a Princeton University and National Oceanic and Atmospheric Administration researcher who was involved with the study. She is based at the federal lab that conducted the analysis.

Climate Stories from the twiterverse

Here are a few more climate stories that grabbed my attention this week.

California leading on climate chnage?

Watching Lake Mead