Coastlines in Danger: The Rate of Global Sea Level Rise is Accelerating

A new NASA study published just yesterday confirms long-held warnings about rising oceans from IPCC and other climate change watch dog bodies. What it found, looking back over the last 25 years, was not only that seas were rising, but that they were rising at an ever-increasing annual rate.

If we took a snap shot of the present day, we’d find that oceans are rising at a rate of around 3.3 mm per year. If that rate were to hold steady, it would translate to a 33 centimeter rise per century. Or about 1.1 feet. This is global average rise, of course. In more vulnerable places like Tidewater, VA, or New Orleans, or Miami, such a larger swelling of the world’s ocean could translate to 2-3 feet due to local conditions like subsidence or ocean current change.

That’s bad enough. But it’s not the whole story.

(NASA study shows that sea level rise rates are accelerating due to the melting of large glaciers in Greenland and Antarctica. The key driver of this melt is human fossil fuel burning and related accumulation of heat-trapping carbon dioxide in the Earth’s atmosphere. Carbon dioxide levels this year will hit near 412 ppm in April-May, a level not seen in 10-15 million years. Video Source: NASA.)

According to NASA, that annual rate of sea level rise is also rising. In other words, it’s accelerating like a car when you slowly but inexorably increase pressure on the peddle.

The present annual increase measured by NASA’s satellites shows a 0.08 mm rate of acceleration averaged over the past 25 years. What this means is that if the rate of increase remains steady, next year seas will rise by 3.38 mm, and the following year seas will rise by 3.46 mm. Extrapolate that to the end of this Century and you’d get an annual rate of rise of around 10 mm per year — or about 3.3 feet every 100 years.

This translates to roughly 26 inches of additional sea level rise from now to 2100 globally — or about 3-5 feet in more locally vulnerable places like Tidewater, New Orleans, and Miami.

(Over the past 25 years, the rate of sea level rise has been accelerating by 0.08 mm per year. A backwards extrapolation by NASA of satellite data is a broad confirmation of sea level observations and predictions by IPCC. However, increasing ice sheet instability in Greenland and Antarctica could further spike rates of acceleration, endangering coastal cities even more. This serious global risk is amplified by continued fossil fuel burning, and moderated by more rapid transitions to clean energy. Image source: AVISO.)

Of course, given the fact that we continue to burn fossil fuels, that the necessary renewable energy transition continues to be delayed by predatory industries and their proxy politicians (primarily republicans like Trump in the United States), there is no guarantee that the rate of annual increase in sea level won’t accelerate faster than it already is. So, for this reason, the new NASA, IPCC-confirming, report should be viewed under a caveat (Dr Eric Rignot points toward sea level rise of greater than 1 meter by 2100).

In other words, if we don’t respond soon, the glaciers in Greenland and Antarctica that are already speeding the rate of global sea level rise could start to really let loose and get us into even more trouble than we already are.


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  1. Sharing on FarceBook

  2. Robert in New Orleans

     /  February 14, 2018

    Vice on HBO “Our Rising Oceans”,

    This episode has an interview with Dr Eric Rignot.
    A must watch for those who not seen it yet.

  3. Robert in New Orleans

     /  February 14, 2018

    2017 Fall Meeting – OS21B: Sea Level Rise and Coastal Flooding I

    • What’s interesting to me here is that the train doesn’t even utilize its whole roof for solar panels. Perhaps 50-60 percent. Given that solar panel efficiency keeps rising, I’d think that solar rail is a growing opportunity. (Tweet pending)

    • Of course, you don’t need to simply just place panels on trains to have solar rail. You can put the panels by the tracks or just simply have a dedicated solar or wind farm providing energy to the line.

    • Panels on cars may provide an added utility by generating power directly. But there’s probably a cost benefit equation involved.

      Would think that solar has greater utility for ships at sea when combined with solar sails and large battery storage capability as we’ve seen in some recent applications.

    Polar vortex defies climate change in the Southeast U.S.
    Winters in the Southeast have been getting colder instead of warmer
    Overwhelming scientific evidence has demonstrated that our planet is getting warmer due to climate change, yet parts of the eastern US are actually getting cooler. According to a new study, the location of this anomaly, known as the ‘US warming hole,’ is a moving target. During the winter and spring, the US warming hole sits over the Southeast, as the polar vortex allows arctic air to plunge into the region, resulting in persistently cooler temperatures.
    After spring, the U.S. warming hole moves north and is located in the Midwest.

    • It’s a pretty recent issue and it will continue to move as the Arctic warms. In other words, it’s not stable. Eventually, it get wiped out altogether and the snap is toward much greater warming. Note that mid latitude weather instability is a feature of polar amplification in the temperature range of 1-3 C above average. It tends to end in the NH after the Greenland Ice Sheet goes through its major large melt pulses. But the indicators are that if we continue warming the Arctic so rapidly, that instability increases before it decreases.

      Also worth noting that the trade off for a warming hole is a warming spike somewhere else. Presently, that’s the U.S. West Coast and Alaska.

  5. Rob orlov

     /  February 14, 2018

    If NASA Wrote this its all FAKE……..

    • Robert in New Orleans

       /  February 14, 2018

      Hola apparatchik, como esta?

      • Robert in New Orleans

         /  February 14, 2018

        I know, I know.
        Do Not Feed The Troll
        But every now and then I love to play “Whack the Troll With Science”

        The entity that refers itself as orlov may or may not be a russian troll, but is sad that it seams that the only things that come out of russia are:
        Dirty Fossil Fuels
        Military Weapons
        Internet Trolls & Trolling
        Car Crash Videos

    • Well then you can pick up some bargain coastal real estate. Apparently it’s selling at a 7% discount. Once everybody figures out that ‘sea level rise is fake’ think how smart you’ll look.

    • Hmm. Someone who believes the moon landing was fake too, then? OK looney toons russian troll bot. Not sure how you made it through the filter, but you can go gather with other similarly insane or ignorant non-people elsewhere. Preferably in that same dark internet hole from which you were spawned and far away from actual thinking, feeling, compassionate westerners.

  6. wharf rat

     /  February 14, 2018

    EU Tells Trump: No Paris Climate Deal, No Free Trade

    France’s foreign affairs minister Jean-Baptiste Lemoyne told the French Parliament last week that his country will insist that TTIP never be revived if Trump carries through on his promise to leave the Paris Agreement.

    “One of our main demands is that any country who signs a trade agreement with EU should implement the Paris Agreement on the ground,” Lemoyne said. “No Paris Agreement, no trade agreement. The U.S. knows what to expect.”

    Given that every country has veto power over new free trade deals, this threat alone would be enough to kill TTIP. Among EU member states, France has been the most skeptical about the free trade deal.
    The EU recently concluded a free trade deal with Japan that includes language on the Paris Agreement, and such language is already in drafts of a free trade deal with the Mercosur countries – Argentina, Brazil, Paraguay and Uruguay.

    • Trump withdrawal from Paris could be extraordinarily damaging to the U.S. economy. In all honesty, I think that any country not signing on to and pursuing Paris should be hit with sanctions.

  7. Jeremy in Wales

     /  February 14, 2018

    As you say towards the end of your article “there is no guarantee that the rate of annual increase in sea level won’t accelerate faster than it already is”.
    This would seem to be the major future unknown. We know that glaciers can change behaviour most famously with the Jacobshavn Glacier that appeared to be in balance from 1955-85 and then in 1997 began to thin and accelerate greatly leading to the famous clips we have all seen.
    If more glaciers in contact with sea water start to change behaviour then will have a major problem and the ones to watch seem to be the Pine Island Glacier (whose behaviour may now be altering) and its neighbour Thwaites.
    The other process, especially in Greenland that will affect sea-level is surface melt, insideous and unspectacular which is likely pollution fed

    • Absolutely.

      It’s one of those issues that could produce complete surprises. And because we don’t a a clear proxy for what’s happening now, it’s difficult to predict the probability of future catastrophic instances such as a large glacial melt pulse at some time in the future.

      Based on meta-analysis of past climates, my opinion is that these risks become acute when temperatures rise to a range of 1.5 to 2.5 C above 1880s averages. Stresses to glacier systems at that point are quite high. We are about 80 percent likely to pass the 1.5 C threshold by or before 2030 on the present emissions pathway.

      • I agree that’s a probable timeframe for a sudden lurch in marine terminating glacier caused sea level rise. I’m worried pine island and WAIS could start adding 5mm/yr by themselves. Add on Greenland and Totten, and we could soon be at 10+mm/yr. this will be an economic disaster.

  8. Erik Frederiksen

     /  February 14, 2018

    In 2016 a numerical ice sheet model by Pollard and DeConto was finally able to put some physics behind what John Mercer and Jim Hansen have been writing about large, fast sea level rise (according to Richard Alley regarding Hansen)

    However, according to Alley, in an email I received from him two days ago, that numerical model “specified a maximum retreat rate that has already been exceeded in Greenland for short times, and the wider glaciers and deeper beds of Antarctica will likely allow faster or much faster retreat than has been achieved in Greenland”, so the several meters of sea level rise over the next hundred years DeConto says their model produced under BAU may be conservative.

  9. Erik Frederiksen

     /  February 14, 2018

    “We are on pace for one meter per century of sea level rise from the ice sheets and glaciers and thermal expansion but the paleoclimate record suggests that if we get a half degree warmer like during the Eemian but maybe not even half a degree warmer, maybe we’re already there, sea level is going to be 6 to 9 meters higher.”
    NASA glaciologist Eric Rignot in 2017


    In Australia, News Ltd and the deniers such as the IPA and Coal backed Industry have created a belief set in especially the finance Industry that GW and Climate Change and the Consequences are all fake.
    Meaning Insurers and the Finance and agricultural and mining and tourism sectors face great threats

    None of our insurers are keeping pace with climate change
    If any Australian company needs to come clean over its climate risks, it’s QBE.
    Not just so shareholders can understand how secure (or not) their capital is as climate impacts intensify.

    This is about Australians being able to see just how perilous our future has become without urgent action to cut greenhouse gas emissions.
    Last October QBE said it expected 2017 to be the costliest year in the history of the global insurance industry, flagging a $US600 million ($767 million) hit to its pre-tax earnings. They weren’t wrong, nor were they alone.
    The triple-whammy of hurricanes Harvey, Irma and Maria hitting the US and Caribbean contributed to a record $US135 billion in payouts globally on natural disasters. Wildfires in California made things worse and, for Australian general insurers, Tropical Cyclone Debbie added to the pain.
    And understandably there have been some drastic responses from within the industry. Hannover Re was even forced to sell its entire stock portfolio, worth €953 million ($A1.5 billion) , prompted by natural disaster claims.

    Last year, individual large claims and natural hazards cost QBE $1.7 billion, or 15 per cent of the company’s net earned premium.
    Compare this to the seven year average of 8.1 per cent to 2010, and you get an idea why QBE called it “unprecedented”.
    Additionally, over the past decade, IAG under-provisioned for natural hazard claims by almost $1 billion while Suncorp under-provisioned by $1.9 billion.
    It appears none of our general insurers are keeping up with the pace of climate change.
    By January, QBE had received its fourth downgrade of the financial year, to the frustration of investors and analysts.
    Although every company faces climate risk to some extent, for QBE it is both acute and direct, since it stems from the impacts of climate change manifesting as claims. Plus, of course, managing the thorny issue of certain parts of the world simply becoming uninsurable.

    The Climate Council has highlighted the increases in extreme weather and climate events Australia is facing as climate change intensifies.
    But gradual changes to the climate also pose risks to transport, agriculture, infrastructure and most other sectors. For insurance companies, these all have a dollar value attached and bringing those figures to light will show the broader public just how acute the risks of climate change are.
    That’s why it’s so important that insurance companies disclose their climate risks and why we need to be ready for what they say.

    • Kiwi Griff

       /  February 15, 2018

      Climate change is beginning to hit insurers in the pocket .

      Last year NZ had record weather related claims .
      This year has already got off to a running start.
      Where I am in NZ we have already had 400% of average rainfall in the last month.

      We are facing another ex tropical cyclone next week. If the storm hits were I live it will result in extreme flooding as we are already soaking wet.
      The outlook for next week.
      “Tropical Cyclone Gita is expected to approach New Zealand from the northwest next week. There remains a large amount of uncertainty with regards to the speed and position of Gita, but the passage of this system across New Zealand would bring a period of highly impactful severe weather. On Monday,there is low confidence of Gita moving onto the country, then the confidence increases to moderate on Tuesday. Correspondingly, there is low confidence of associated severe gales and heavy rain spreading across central and northern New Zealand, then the confidence increases to moderate on Tuesday. In addition to severe gales and heavy rain, winds associated with Gita would cause large waves to affect coastal places, and the expected storm surge would allow run-up of waves in low-lying coastal places particularly at high tide.”

      It is unfortunate that it will take such events to wake the populace up to what we have done to this planets atmosphere .

      • Mark in OZ

         /  February 16, 2018

        Great points Frank S!
        Pressure is mounting to make ‘ESG’ reporting mandatory on the ASX 200 (Australia’s main stock exchange). and forward looking companies are already ‘on-board’. Those that are resisting ( no surprise) are the ones that have the most to lose. Just a matter of time, really before they are compelled and if they still resist, global ratings agencies ( i.e. Morningstar) will expose their frailties. The Neo-lib philosophy (rampant in Straya) is just ‘kick the can’ and hope nothing bad happens on ‘our’ watch. An endless line of those willing to take the money’ and run.

    • This kind of organized promotion of climate change denial is a crime against human civilization and the natural world. It makes the world more dangerous and costly for everyone. Meanwhile, profits from perpetrating the crime go only to a handful of people who hurt themselves, their families, and their peers in the end as well.

  11. wj long

     /  February 15, 2018

    CLIMATE SCIENCE SPECIAL REPORT suggested 8ft of SLR by 2100, Which I do not have a link for. But Mercer…..

  12. Dave McGinnis

     /  February 15, 2018

    KEYW my home town is a good place to measure MSL change as it is a stable platform and has a good long record. One inch per decade is accurate looking back, but looking forward it might be more like 3″. There has been a shift since about 2000.

  13. kassy

     /  February 15, 2018

    Climate change to shift timing of glacial runoff

    The distribution of freshwater runoff from glaciers throughout the year may change as the climate warms, predicts a study in Nature Climate Change. During this century, for around half the 56 glaciers examined, annual runoff is expected to increase to a peak then reduce, whilst annual runoff for the remainder seems already to have peaked and is predicted to continue to fall. What’s more, the proportion of the run-off taking place in the melt-season looks set to decrease in more than a third of the basins.

    Although there was substantial variation between basins, the researchers came to some key conclusions. More than one third of the basins are set to experience an overall reduction in runoff greater than 10% during at least part of the melt-season by the end of the century, they found. It is important to note that these glacier-containing basins house almost one-third of the global human population. The disruption of glacial runoff could have serious effects on these communities, as well as countless natural habitats downstream from melting glaciers.

  14. “the figures are not waiting”
    from a poem by Susan Stewart (

    “… Wake up.
    The wind is not for seeing,
    neither is the first
    song, soon half-
    way gone,
    and the figures,
    the figures are not waiting…”

  15. wharf rat

     /  February 15, 2018

    A ship has made a winter crossing of the Arctic without an icebreaker for the first time as global warming causes the region’s ice sheets to melt.

    The tanker, containing liquefied natural gas, is the first commercial vessel to make such a crossing alone during the winter months.

    Belonging to the shipping company Teekay, the ship Eduard Toll made its way from South Korea to the Sabetta terminal in northern Russia in December.

    From there, it sailed to Montoir in France to deliver a load of liquefied natural gas

  16. Robert E Prue

     /  February 15, 2018

    James Hansen suggested the rate of sea level rise could double every 10 years. 40 years from now, sea level could be going up over a foot per decade.

  17. kassy

     /  February 15, 2018

    Who should be held responsible for the Aliso Canyon gas leak?

    SoCalGas’s corporate dysfunction and a lack of oversight for underground gas storage facilities are responsible for the largest methane gas leak in American history, USC-led study finds

    The SS-25 well is 64 years old and 8,750 feet deep. An underground safety valve designed to shut off flow to the surface when abnormal conditions occurred was removed in 1979 and never replaced, according to the study.

    “If a functional kill valve were in place for well SS-25 in October 2015 when the leak began, the leak could have been stopped in a matter of hours or days rather than after four months,” Meshkati said.

    SoCalGas made eight unsuccessful attempts to stop the leak using kill procedures. It later contracted a well control company to “facilitate a proper kill procedure,” the study reported.

  18. Jeremy in Wales

     /  February 15, 2018

    Because I like trains, my model trains and Flying Scotsman, as a kid, ran on electric even my childrens Thomas the Tank had batteries and it seems that we are now moving towards more sustainable real trains:

  19. Steve Bloom

     /  February 15, 2018

    Things move fast here! Reposting this late comment from the prior thread to make sure it doesn’t get missed:

    Robert, please post on Amazing backstory (most intensive climate modeling effort ever AFAIK — thanks, failed huge nuclear weapons project!), plus it means that paper has far more weight. (Other recent projections don’t show the precip decrease, and some even disagree about ridging persistence.) Of course there will be other downstream effects on northern hemisphere and tropical circulation; more papers to come from this group, I expect..

    • Thanks for this Steve. Will see what I can do.

    • Robert in New Orleans

       /  February 16, 2018

      Most Excellent Article!
      Now let’s use that great computational power on modeling ice sheet melt and subsequent sea level rise so I know when to put my house up for sale.

      • kassy

         /  February 16, 2018

        Interesting article:

        “Three variables accounted for 95 percent of the change. Two of them specified the size of snow particles on sea ice, which affects how much sunlight is reflected away. The last one, known as the “thermal conductivity of snow,” essentially defines how fast heat can move through ice. Like the other two variables, it is normally treated as a constant in the dedicated ice model the team used. But in this case, the researchers toggled it within a range that reflected its real-world variability.”

        This is like the glacier melt modelling. The model outputs were out of line until they added the physics where glaciers collapse above 100m of height.

        It might be worthwhile to check the models for more variables which can be replaced with ranges of observational data?

        On another note we have come a long way in modelling with the increase in computing power.

        For anyone interested in history of modelling see the Theory chapters here:

      • Robert
        I knew New Orleans before Katrina. It was a great and beautiful city. Reluctance to leave is not hard to understand.

        • Robert in New Orleans

           /  February 16, 2018

          I actually moved to New Orleans in 1997 and I have ridden out way too many hurricanes since then including Katrina. I know that I have to move sooner or later because I risk being a stranded asset homeowner if I don’t. I might have picked up and left by now, but I am also responsible for my elderly father who is in his eighties and lives nearby. He is stubborn and doesn’t want to move away with me and my wife to somewhere safer. I cannot and will not leave him behind, on the other hand his memory is starting to fail and when he has to move in with us, then is probably when I will move out of New Orleans.

      • The situation is similar with me and my Mom, down to the stubborn. Very sad. We have such lovely memories of the Gulf Coast.

  20. Hilary

     /  February 15, 2018

    from New Zealand:
    Judy Lawrence: Getting climate-change retaliation in early key to success

    “Last year was odd being the fifth warmest year on record, with the pairing of both high rainfall and severe drought. Why are we reacting to these as they happen? We have known about the possibility of them for decades. What can be done to shift our actions from reactive to more planned adaptation?
    Well, change is starting to happen. Take coastal hazards and sea level rise, for example, the impact of which is already being felt.
    Councils, iwi and communities such as Hawke’s Bay and Dunedin have started community-based projects to discuss what can be done. But they will not be able to cope alone.”

    I live in Hawkes Bay, an area very vulnerable to coastal hazards related to climate change & sea level rise (as well as tsunami). Our local councils have begun a process to plan for what’s a coming. They set up a main committee and initiated 2 community based panels to look at future options in the short, medium & long term for the various sections of our local shoreline. This was all supported by scientists, engineers, local maori and have costings for the options. The community panels’ reports are now complete & will begin their process for approval by our local councils.
    I’m not altogether sure about some of their choices but at least this is a constructive start. And now we just have to hope all the local councillors will be brought up to speed on this. Currently our (Napier’s) storm water infrastructure is creaking through lack of maintenance & fails from time to time during heavy rainfall events. Maybe they will focus on all this instead of the various vanity projects they have been wasting the city funds on!

    I am also posting all the link just in case there are some Scriblers who may want to read about this process in more detail. And the final community report is under the Resources section:

  21. More and better models with greater detail and ‘confidence’ is of course desirable, but then again there is this interesting perspective:

  22. Mblanc

     /  February 19, 2018

    So the new work on SLR has got me thinking about Hansen’s interest in doubling rates.

    If we take a start point as the widely quoted current rate of 3.3mm/yr, with 0.084mm/yr acceleration, my primitive mathematical ability gives a doubling time of roughly 40 years.

    Given that we are effectively looking in the rear view mirror, the doubling time is probably a wee bit lower currently, and there are also margins of error to think about. At least this gives us a more convincing lower boundary for how fast things are changing, but I can’t see how the rate of acceleration could fail to increase in the future.

    Part of me thinks the current 3.3mm/yr figure is looking a bit out of date, as it is only a touch higher than the average (3.1mm/yr) over the whole satellite era. Tamino suggests that the current rate is around 4.8mm/yr. That really messes up my suggestion as to the current doubling rate if we use that figure. but then the snapshot of acceleration (and SLR) in any one year is pretty noisy, and therefore not very useful.


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