JUL 13, 2017

When will sea level rise make you move?

WRITTEN BY: Kathryn DeMuth Sullivan

Here’s a scary statistic: by 2035 about 170 US communities will be in a state of chronic inundation. That’s less than twenty years from now. Is your community one of those?

A new study from The Union of Concerned Scientists is trying to make those number real to coastal residents now before it’s entirely too late. The study, entitled, "When Rising Seas Hit Home," was published in the journal Elementa and states that by 2100, up to 670 U.S. communities could face chronic inundation. But what does that even mean?

The scientists define chronic inundation as “flooding that occurs at least 26 times a year over at least 10 percent of a community's usable, non-wetland area, disrupting lives and businesses and making normal routines impossible.” The question they’re asking is, how many times of your basement flooding with seawater would it take for you to consider climate change an urgent problem?

"We hope this analysis provides a wake-up call to coastal communities — and us as a nation — so we can see this coming and have time to prepare," co-author Erika Spanger-Siegfried.

The team of scientists analyzed sea level rise in three situations: low, intermediate, and high. A "low scenario" constitutes the least amount of disruption and adheres to the Paris Climate Accord’s goals. Under this scenario, the average global sea level rise would stay below 1.6 feet.

With an "intermediate scenario" the scientists assumed that carbon emissions would peak at 2050 and decline in the latter half of the century. That would leave the planet with roughly 4 feet of sea level rise and a moderate rate of ice sheet melt.

But with a "high scenario," carbon emissions would continue to rise throughout the century and would result in a 6.5-foot rise in sea level. That might sound unreasonable because it would mean such failure on our human effort, but UCS scientists have said that such a scenario is "increasingly plausible" due to the accelerating loss of ice sheets.

To make their research accessible and user-friendly to the average layperson, the UCS developed an interactive online map that shows inundation models in the three scenarios. You can go to arcg.is/2ubkUCZ and zoom in and out of streets to see how your own neighborhood will fare.

UCS senior climate scientist Astrid Caldas told The Daily Press in a phone interview, "What we're trying to do is identify which areas on the coast are going to be hit first. And hope that the policymakers at the local and state levels start thinking about actions and start trying to find resources to do what they need to do to either prevent, accommodate or, if need be, to move some people away from the flood areas. Because the sea's coming."

Sources: UCSUSA (2), The Daily Press