This is the extent of flooding from Hurricane Sandy in Cape May, NJ (left) vs. the area that would flood twice monthly by 2100 due to sea level rise (right)

This Is Your Planet on Sea Level Rise. Any Questions?

, climate scientist | October 27, 2017, 11:02 am EST
Bookmark and Share

One of the most powerful televised public service announcements of my youth inspired this post.

There are moments when your own data stops you dead in your tracks. I had one of those moments a few months ago as we were preparing to release our When Rising Seas Hit Home report.

The results were so stark, the case for sound climate policy so clear that I can think of no better way, on the eve of the fifth anniversary of Hurricane Sandy’s devastating landfall, to convey where sea level rise could take us than by spoofing what was arguably the most powerful televised public service announcement of my youth.

Is there anyone out there who still isn’t clear about what sea level rise does? OK. Last time.*

This was the extent of flooding from Hurricane Sandy on Long Island

This is the area that would flood twice monthly by 2100 due to sea level rise

Any questions?


This is the extent of flooding from Hurricane Sandy in northern New Jersey (left) vs. the area that would flood twice monthly by 2100 due to sea level rise (right)

Any questions?


This is the extent of flooding from Hurricane Sandy in Cape May (left) vs. the area that would flood twice monthly by 2100 due to sea level rise (right)

Any questions?


*Yes, this was the actual language used in the PSA.

Data sources: UCS When Rising Seas Hit Home; FEMA Hurricane Sandy Impact Analysis; OpenStreetMap; Partnership for a Drug-Free America

Kristy Dahl

Posted in: Global Warming, Uncategorized Tags: ,

Support from UCS members make work like this possible. Will you join us? Help UCS advance independent science for a healthy environment and a safer world.

Show Comments


Comment Policy

UCS welcomes comments that foster civil conversation and debate. To help maintain a healthy, respectful discussion, please focus comments on the issues, topics, and facts at hand, and refrain from personal attacks. Posts that are commercial, self-promotional, obscene, rude, or disruptive will be removed.

Please note that comments are open for two weeks following each blog post. UCS respects your privacy and will not display, lend, or sell your email address for any reason.

  • tidegateguy

    I have a question…
    When will the rate of sea level rise actually increase to a amount that is greater than the rate of sea level rise that was occurring in the 19th century?
    The mean sea level trend (based on sea level measurements from an actual tide gage) at The Battery, New York (NOAA Station 8518750) was and is 2.84 mm/yr plus or minus 0.09 mm/yr. (This is about a foot per century.)
    The trend line from 1860 to 1880 has the same slope as the trend line for the past 120 years.
    Google “NOAA Sea Level trends” and see for yourself. The Batttery is not an anomaly. All of the sea level trends show the same thing. Constant rates of sea level rise / or fall for a few sites. San Francisco has a tide gage record that begins in 1854.
    Question #2: how many centuries of sea level rise will it take before the sea level (sans hurricane storm surge) causes high tides to flood the areas shown in your article?
    Question #3: if the rate of sea level rise remains at 2.84 mm/yr indefinitely, isn’t that proof that sea level rise has nothing to do with climate change.

    • Apple hater

      Stop spewing all that factual information, you’re going to spoil the purpose of this article.

      • tidegateguy

        You caught me. (That was the idea.)
        I am not a scientist. I’m an engineer. We engineers use science to solve problems. If we get the science wrong, the thing we are engineering will fail. Failure is not an option.
        This is why I am concerned about science.
        Scientists, on the other hand, if they get the science “wrong” a couple of billionaires named Soros and Steyer will stop sending them money.

    • Greg Egan

      I googled the NOAA information And I believe I looked at the same graph/data you’re referring to. 2.84 mm /yr.
      The trendline you’re talking about is also called “the line of best fit”. that is the average over the timeline, it’s not saying that every year the sea level rises 2.84 mm. for example, if you measured sea level rise for 100 years and the first 50 of those years the sea level rose 1 mm and the next 50 years the sea level rose 5 mm per year, The trendline would show an average of 3 mm per year over 100 years.
      I hope that helps at least a little. I think your question it’s a great one and I hope a scientist from UCS will give you a complete answer. i’d say if you don’t see an answer here in the comment section by Tuesday, call them up. It’s an important question and I’d like to see an explanation from an expert.

    • Kristina Dahl

      Thank you, tidegateguy, for these questions, and Greg Egan for your follow up.

      For question #1, Greg is absolutely right. The trend lines you see on the NOAA sea level rise records are average trends over the entire length of the record. So they do not capture changes in the rate of sea level rise over the course of the record. We know from global studies, for example, that the pace of sea level rise has already accelerated to more than double what it was in the 20th century. My blog post from earlier this year summarizes some of the latest science about this acceleration: http://blog.ucsusa.org/kristy-dahl/sea-level-rise-iphone. The upshot is that the average rate of sea level rise was about 1.1 mm/year during the 20th century compared to about 3 mm/year now. More and more of that sea level rise is happening due to ice sheet melting (see https://www.nature.com/nclimate/journal/v7/n7/pdf/nclimate3325.pdf?origin=ppub for some very recent data on this.)

      Question #2. The maps I show here represent the area that would flood 26 times per year with a scenario of 6 ft of sea level rise by 2100. These floods would occur largely due to simple high tide flooding rather than storms.

      Question #3. We know from many studies that the pace of sea level rise is accelerating. Because of the inertia of Earth systems, even if we were to stop emitting greenhouse gases today, sea level will continue to rise as Earth systems adjust to our past emissions. There is little question that sea level will continue to rise, though it’s our future emissions and the Earth’s response to those (particularly with regards to ice melting) that will determine how quickly sea level rises in the future. The rate of sea level rise has not stayed steady at 2.84 mm/yr and is not expected to in the future either.

      Hope that answers your questions, and thank you for reading!