Planetizen - Urban Planning News, Jobs, and Education

Sea Level Rise Will Not Be Uniform

As the climate warms, the world's glaciers and ice sheets are melting, but sea level increase will be greater in some places due to the earth's rotation and gravity, according to a newly released study by the NASA Jet Propulsion Laboratory.
November 27, 2017, 2pm PST | Irvin Dawid
Share Tweet LinkedIn Email Comments
The TerraMar Project

How much can you expect rising sea levels to threaten your coastal city? The answer lies in part in knowing which glacial ice melts affect it, so planners can determine how much of an increase to prepare for.

"NASA's Jet Propulsion Lab has mapped how changes in these giant ice fields influence sea levels both nearby and thousands of miles away," reports Christopher Joyce, science correspondent for NPR (audio available). "They published their results in the journal Science Advances."

It turns out that in New York City, the sea level would be affected more by melting ice on the northern end of Greenland than much closer ice in southern Greenland, or even ice in Canada.

Scientists are now using this information to predict the future for American cities, but they're also building in a lot of local geographical information.

"The National Oceanic and Atmospheric Administration (NOAA) is putting together a sea level rise grid for the country, one that will factor in local conditions as well as the effects of faraway melting ice," adds Joyce.

Sea level decrease?

Yes, melts in the eastern Greenland ice sheet could cause a minor drop in sea level in Norway while raising sea levels off Tokyo by several inches, writes Joyce.

Unrelated to the NASA report, a 2007 study found that the melting of glaciers outside Juneau, Alaska is causing the land to rise faster than the sea level, resulting in net sea level decline.


Jeff Goodell’s new book, The Water Will Come: Rising Seas, Sinking Cities, and the Remaking of the Civilized World was reviewed by Jennifer Senior for The New York Times on Nov. 22. While Joyce of NPR indicates that sea level has risen an average of eight inches over the last century, Senior writes that the authors of climate reports for the 2015 Paris agreement estimate sea level rise at over three feet by 2100.

Now many scientists believe that estimate is too low. Some say the sea could rise as much as six feet; others say even more than that.

“For anyone living in Miami Beach or South Brooklyn or Boston’s Back Bay or any other low-lying coastal neighborhood,” Goodell writes, “the difference between three feet of sea level rise by 2100 and six feet is the difference between a wet but livable city and a submerged city.”

"Of all the American cities in this book, Miami seems least equipped to handle a rise in sea level, founded as it is on pleasure, real estate and the inalienable right to not pay state income taxes," adds Senior.

Full Story:
Published on Friday, November 24, 2017 in NPR
Share Tweet LinkedIn Email