Louisiana declares coastal state of emergency

Rising seas in the Gulf of Mexico have been eating away at Louisiana's coastline for decades.

Now the situation has reached "crisis" levels according to Louisiana Governor John Bel Edwards.

Governor Edwards declared this state of emergency for Louisiana's coastline Wednesday.

Climate Cast: America's early climate refugees

The Louisiana declaration comes as a new study in the journal Nature Climate Change  predicts as many as 13-million Americans could migrate away from the coast if global sea level rises the expected 6-feet by 2100.

That’s a significant climate migration, and will create millions of new ‘climate refugees’ relocating in other U.S. cities.

I talked with Mashable Science Editor Andrew Freedman about the growing reality of American climate migrants now and in the future on MPR's Climate Cast this week.

Here's a clip from Andrew's Mashable piece this week.

The biggest net population gain would be in Texas, which would see migrants from Louisiana, Virginia, and low-lying areas in the Lone Star State, the study found. In particular, the Austin and Round Rock area of Texas could see a net gain of as many as 820,000 people, depending how well coastal areas adapt to sea level rise.

Orlando and Atlanta are also projected to receive more than 250,000 climate migrants through 2100. Phoenix and Las Vegas, both of which are already struggling to keep up with water and electricity demand, could also see an influx of people.

The biggest population-losing cities are not that surprising: New Orleans and Miami.

In Florida, the area from West Palm Beach south to Miami is projected to lose as many as 2.5 million people by 2100 due to sea level rise-related flooding, the study found. Some 2 million people could still flee the area even if climate change adaptation measures are undertaken, such as building sea walls, raising coastal roads to prevent them from flooding regularly, keeping salt water from entering water supplies, and other projects.

Nine states could see a net population loss, including Massachusetts, South Carolina, California, Virginia, New Jersey, Louisiana, and Florida.

Climate change: A stealthy threat

The biggest takeaway as we think about climate change now and in the future?

Many think of climate change as a slow background change. Certainly it is that on many levels. But then periodic catastrophic events hit on top of that elevated 'base state' of a higher sea level, and a warmer, wetter and more powerful atmosphere.…and boom. That’s when sudden increasingly damaging events and economic shock waves happen. Suddenly events and situations become much worse and much costlier because of climate change.

Think of it this way. It’s like taking your foot off the brake and letting your car pick up speed downhill. You go faster and everything is fine…until you hit something. Then the damage is much worse.

That’s why climate change is such a stealthy threat, that suddenly becomes severe or even catastrophic.