New Report: Sea Level Rise To Accelerate - A Lot

 A chart from a new NOAA report on sea level rises
over the next 30 years paints a grim picture of the 
future. Click on the image to make it bigger, easier to see.

 We're starting to get accustomed now to reports of "sunny weather" coastal flooding, in which high tides in the absence of a storm still cause a little flooding in low-lying ocean front areas.  

This problem is going to get worse in the next three decades. A lot worse. 

Sea levels along United States coasts have risen by ten to 12 inches on average in the past century. That doesn't seem like a lot, until you consider how many roads, houses, buildings and infrastructure are barely above sea level. 

The new report says sea levels in the next 30 years will rise by as much as they did in the past century going up another ten to 12 inches. 

As the Washington Post reports:

"Kristina Dahl, a principal climate scientist with the Union of Concerned Scientists, said research she and colleagues have done suggest that 10 to 12 inches of sea level rise by 2050 would put roughly 140,000 homes at risk of 'chronic inundation,' or flooding every other week on average."

Due to more local changes in land and sea interactions, this sea level rise will be uneven, the report indicates.   Along the East Coast, the projected rise is about 10 to 14 inches, according to the report. It'll be worse on the Gulf Coast, with projected rises of between 14 and 18 inches. 

The faster rate of sea level rise along the Gulf Coast is interesting because, fossil fuels are making glaciers melt faster, contributing to sea level rise. And, as NPR points out, oil and gas extraction along the Gulf Coast is making the land sink, contributing to the sea level rise. So that's two ways fossil fuels are contributing to the problem. 

It's not just the visible flooding that's the problem. Subtle rises in sea levels can make corrosive, salty ocean water infiltrate sewers, building sub-basements, and drinking water supplies. 

And all that that says nothing about what happens when a big storm comes along. 

Moderate flooding - usually enough to cause damage - is forecast to happen ten times as frequently in 2050 as it does now, the NOAA report tells us.  Major coastal flooding which is inevitably terribly destructive, will be five times as frequent as it is now, the NOAA report says. 

This latest bit of bad climate news comes courtesy of the National Oceanic and Atmospheric Administration, or NOAA.  This federal study is an update of one done in 2017 and takes advantage of cutting edge modeling from a recent United Nations report on climate change and improved ice sheet modeling and more accurate observational data.  NOAA also used readings from tidal gauges and satellite imagery to complete their analysis, according to the Washington Post. 

The sea level rise projected by NOAA over the next three decades is pretty much set in stone even if we waved a magic wand today and eliminated almost all greenhouse gas emissions. 

The NOAA report tells us that depending on how well or poorly we do with limited greenhouse gases, sea level rises might stabilize at about two feet above the historic average or gaining by nearly eight feet. 

Coastal flooding has already gotten a lot more frequent. Another report last year found that coastlines in the United States had twice as much flooding as they did just 20 years ago, the Washington Post notes. 

Climate change is causing sea level rise as a warmer climate melts ice that is not floating on the sea.  Arctic sea ice, if it all melts, won't raise sea levels much because it's already in the water.  It's like if the ice cubes melt in your glass of gin and tonic, the amount of liquid in your glass won't go up.

But, as ice melts from Antarctic, or the Greenland ice cap, or the mountain glaciers around the world, the water ends up in the ocean and levels go up. 

To make matters worse, water expands a bit as it warms up.  A warmer ocean would get "bigger" and contribute to sea level rise.

Those Antarctic and Greenland ice sheets are the real wild card in terms of sea level rise. The amount of warming sufficient to cause rapid melting in those two places is a big unknown, the NOAA report acknowledges. 

"....ice sheet instability is difficult to model and there is great variability in current modeling approaches. Efforts are underway to improve our understanding of ice sheet dynamics in order to more precisely project future sea level rise in response to continued emissions and warming," the report states. 

Despite dire reports like this, develop continues at a fast pace along many of the nation's coastlines.  At some point, something's got to give.