Jim Hansen Says Your Favorite Coastal Cities Are Going To Drown

If sea levels rise substantially with climate change
what do we do with this big South Florida neighborhood?  

This hasn't been the greatest week in climate change news.

We learned, as I noted Tuesday, that June, 2015 was the hottest on record, according to NOAA. And this year has a strong chance of being the hottest on record, beating the mark set last year.

Then former NASA chief climatologist Jim Hansen came along to really put people in a bad mood. For good reason, too.

Hansen is the guy in 1988 who brought climate change to the national conversation during congressional testimony during that hot summer.

Climate change has been, pardon the pun, a hot button issue ever since.

Hansen's science and general predictions since then about global warming have been spot on, but he's got a lot of people hoping he's totally wrong about how sea levels will change as the planet warms.

He says sea levels will rise by about 10 feet by 2100, much faster than outfits like the United Nations Intergovernmental Panel on Climate Change, or IPCC project. The IPCC has been saying the sea level rise would be something like three feet by the year 2100.

Many coastal cities tend to be just a few feet above sea level now, so you can see how a rise three times as much as current predictions would be a HUGE problem.

Here's how The Daily Beast put it as they described Hansen's latest research and comments on sea levels

"This roughly 10 feet of sea level rise - well beyond previous estimates - would render coastal cities such as New York, London and Shanghai uninhabitable. 'Parts of (our coastal cities) would still be sticking above the water,' Hansen says, 'but you couldn't live there.'"

We've heard these dire warnings about coastal cities and sea level rises again and again as we talk about global warming.

What's different here is Hansen says this coastal inundation will come much sooner than previous research projected.

Hansen's work indicates Earth's ice is melting faster and the oceans are getting higher much faster than expected.

If Hansen and the 16 other scientists he worked with on this are  right, it would be much harder than expected to buttress coastal cities against the rising tides. And they'd have to do it much faster.

It would cost untold billions of dollars to do this, and the faster you have to raise that kind of money, the harder it is.

As the Daily Beast noted, Hansen's work might throw a monkey wrench into the big United Nationsl climate summit in Paris this coming December.

The goal there is to limit Earth's warming to 2 degrees Celcius, but Hansen says even an increase of 2 degrees would be catastrophic, especially for coastal areas.

So, will everybody at the summit just give up and say we can't fix this and to hell with it? Who knows?

CAVEATS

There are some caveats to this Jim Hansen bombshell. The research isn't peer-reviewed yet, having been published in an open access journal in which peer review takes place after publication, not before.

It will be a while yet to see whether other scientists poke holes in Hansen's conclusions after they review it.

Climate scientist Michael Mann, a guy not shy about warning about the dangers of climate change, said he is a little skeptical of Hansen's assumptions that melting of ice shelves will accelerate constantly with time.

Might there be slowdowns in the rate of ice warming? We don't know. Still, Mann said Hansen's research is good in that it puts out provocative ideas for other scientists and policy makers to chew over.

It'll be interesting to see how well Hansen's research holds up under scrutiny. As I noted, he does have a track history of being very accurate with his work.


RISING TIDE IN SOUTH FLORIDA

If Hansen is right, one place that's particularly screwed if Hansen is right is South Florida

The Globe and Mail had a piece  about the trouble the southern tip of Florida is in if sea levels rise even slower than Hansen and his buddies suggest:

"Few places are as geographically ill-equipped to deal with rising water as southern Florida. Not only is much of the land barely a few feet above sea level, it also sits on a bed of porous limestone and sand, maked measures such as dikes far less effective.

Higher sea levels would eat away at the barrier islands that buffer the coast against powerful storms - which is hugely problematic, given that more powerful storms are one of the hallmarks of climate change. The rising water also threatens to slip inland and contaminate the wells that provide much of the region's drinking water."

Even for people in South Florida who live above the level that water is projected to rise to, they're still screwed. Yes, the house might be above water, says Harold Wanless, chair of the Department of Geological Science at the University of Miami.

But Winless said, sewage services are kaput, there might not be electricity, and the roads to and from this house might be under water. Sounds lovely, no?

Eventually, a lot of people are going to have to abandon South Florida. They're still building seaside condos and shopping centers and entertainment places like mad. So what happens to all that when the water rises?

As the Globe and Mail points out, what if insurance companies stop covering these at-risk properties? It you can't insure your house or building, it's basically worthless.

If people abandon lots and lots of threatened property, then what? Are banks left on the hook for abandoned mortgages? What happens to commerce in what's left of the area. Where do you put all the people who leave South Florida? Will there be severe economic ripple effects throughout the nation?

If Jim Hensen is right, things are going to get very VERY messy in the coming decades. And not just with the climate and sea levels alone.