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Rising sea levels will be too much, too fast for Florida

It is amazing for me to see the very aggressive building boom underway in south Florida; on the beaches and barrier islands, throughout downtown and in the low western areas bordering the Everglades. They…

At some point, the postman will not always get through. Dan Anderson

It is amazing for me to see the very aggressive building boom underway in south Florida; on the beaches and barrier islands, throughout downtown and in the low western areas bordering the Everglades. They are building like there is no tomorrow. Unfortunately, they are right.

The US National Oceanic and Atmospheric Administration (NOAA) published its assessment of sea level rise in 2012 as part of the National Climate Assessment. Including estimates based on limited and maximum melt of the Greenland and Antarctic ice sheets, it anticipated a raise of 4.1 to 6.6ft (1.25 to 2m) by 2100, reaching 2ft (0.6m) by around 2050 and 3ft (0.9m) by around 2075.

This degree of sea level rise would make nearly all the barrier islands of the world uninhabitable, inundate a major portion of the world’s deltas, upon which hundreds of millions of people live, and leave low-lying coastal zones like southeast Florida increasingly difficult to maintain infrastructure services for and increasingly vulnerable to hurricanes and storms.

The flooding of Florida will begin in earnest within the next 25 years. Peter Harlem, Florida International University

Most models of projected sea level rise assume a gradual acceleration of sea level in line with gradually accelerating ice melt. But our knowledge of how sea level rose in the past paints a very different picture of response to climate change.

At the peak of the last ice age 18,000 years ago sea level was some 420ft (128m) lower due to the vast quantities of water locked away in continental ice sheets. Subsequent ice melt was not a gradual process, but rather a series of very rapid pulses of sea level rise interspersed with pauses in which coastal environments formed. During pulses the seas rose between 3-30ft (0.9-9m) fast enough to drown not just reefs, sandy barrier islands, tidal inlets and other coastal features, stranding their remnants across the continental shelf, now disappeared beneath the ocean.

The cracks are showing

That is what happens when climate change warms enough to destabilise some ice sheet sector. It rapidly disintegrates, resulting in a rapid rise. This is what is beginning to happen to the Greenland ice sheet, where surface melting has concentrated dust and black carbon in the ice on the melting surface darkening and further accelerating the surface melt.

More importantly, warmed ocean water has accelerated the ice melt at both poles, working its way into the glacial fjords under the ice sheet in Greenland and under the outlet glaciers around the Antarctic ice sheets. While this “warm” water is only 2-4°C, even this moderate heat is capable of vast amounts of ice melt, and once started, the melt creates positive reinforcing feedbacks that speed the acceleration far beyond anything originally anticipated.

The inundation will speed up over the decades as more meltwater boosts the oceans. Peter Harlem, Florida International University

Water on the melting ice surface adsorbs more heat which accelerates the surface melt. Meltwater percolating down through the ice lubricates the base permitting faster motion, which results in more extensive fracturing, in turn allowing more, warmer water through the fractures and into the interior of the ice sheet, and so on. We are most certainly witnessing the onset of a rapid pulse of sea level rise.

The view from above

Flying 50 miles over Greenland’s interior last summer, the Jacobshaven (or Ilulissat) Icefjord looked like the bed of a giant meandering stream carved on the surface of the ice. The bottom of the channel, some 500ft (152m) below the level of the ice sheet above was moving faster than than the ice above, having been penetrated by the warmed ocean water. As a result the ice has dramatically fractured and has accelerated, from moving a couple of miles in a year to over 20. A spectacular but most disturbing experience.

Flying over the fractured Greenland ice sheet - we’re in for a bumpy ride. Michael Haferkamp, CC BY-SA

Even if we stopped burning fossil fuels tomorrow, the greenhouse gasses already in the atmosphere will continue to warm the atmosphere for at least another 30 years. And as most of this heat has already been absorbed by the oceans, which have the capacity to store heat for centuries, the overall effect on ice sheet melt will continue for centuries, accelerating all the way. If we are at just 5ft (1.5m) rise at the end of the century, sea level will be rising at a foot per decade – think about trying to maintain a port facility anywhere with that.

Florida – here today…

To consider the risk in present investments is beyond sobering. By the middle of this century most of the barrier islands of south Florida and the world will be abandoned and the people relocated, while low areas such as Sweetwater and Hialeah bordering the Everglades will be frequently flooded and increasingly difficult places to live. Florida will start to lose its freshwater resources, its infrastructure will begin to fail, and the risk of catastrophic storm surges and hurricane flooding will increase.

Florida counties should be planning for their future to determine at what point the costs of maintaining functional infrastructure, insurance, and human health and safety becomes economically impossible. Already, there are areas and properties that will become unlivable within a 30-year mortgage cycle. The Four-county Compact on climate change in southeast Florida has some 1,200 action items to help ensure some stability for the communities there.

And by the end of the century, large parts will be uninhabitable. Peter Harlem, Florida International University

For south Florida, forget the levees and dikes. That may be fine for New Orleans and the Netherlands, but not here where the limestone and sand under our homes is much too porous and permeable. For each day action is put off, it becomes harder and more expensive to make the inevitable changes required. Without planning, there will come a point where society will collapse into chaos.

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27 Comments sorted by

  1. takver takvera

    Journalist and Editor at Indymedia

    Interesting article. I'd like to see recent graphs showing rate of ice mass loss from both Greenland, West Antarctica and East Antarctica. It is clear rate of ice mass loss is accelerating, but at what rate. I'd like to see some modelled projections for likely sea level rise later this century. I thought 1 metre was the likely level by 2100, but from reading this it might be 1.4 to 2 metres or more. Is that right? What is the upper physical limit (worst case)?

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  2. eideard

    logged in via Twitter

    No one seriously involved in progress and politics in the United States - not always mutually exclusive - wastes time trying to characterize development decisions in the neo-Confederacy as being farsighted or even appropriate.

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  3. Kevin Marshall

    IT Consultant at Engineering

    Being an ex-beancounter I like to verify figures.
    Professor Wanless says
    "Including estimates based on limited and maximum melt of the Greenland and Antarctic ice sheets, it anticipated a raise of 4.1 to 6.6ft (1.25 to 2m) by 2100"

    Click on the link to the Report, and you get the statement:-
    "Scientists have very high confidence (greater than 90% chance) that global mean sea level will rise at least 8 inches (0.2 meter) and no more than 6.6 feet (2.0 meters) by 2100."

    Where can we get such…

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    1. David Arthur

      resistance gnome

      In reply to Kevin Marshall

      "Back in 2007 the UNIPCC was forecasting a top end of sea level rise of less than one metre. " Correct: they specifically excluded ice melt from their projections for two reason
      1) because at that time large-scale ice melting was only just starting, and is yet to be detectible in sea level observations.
      2) instrumentation was yet to be deployed to provide comprehensive monitoring.

      "Shepard et al have ice melt in 2005-2010 of 344 Gt yr-1, equivalent to .94mm [/yr] sea level rise. So what accounts for the other 2.15mm?" Largely thermal expansion - I understand that thermal expansion pretty well accounts for sea level rise from ~1880 to ~1980, after which there's been an ever-increasing acceleration.

      There's a nice graph which illustrates this trend-"Global Mean Sea Level (GMSL) - 1880 to 2012" - at the page of John Church's CSIRO group: http://www.cmar.csiro.au/sealevel/

      I wonder if this group is to be targetted by Mr Abbott's CSIRO cuts?

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    2. Kevin Marshall

      IT Consultant at Engineering

      In reply to David Arthur

      Thermal expansion could well account for the the sea level rise from ~1880 to ~1980. If Church's figures are a good indicator of reality, then much of the rise up to 1950 will be due to natural factors, not human.
      The satellite data from 1993 is spliced on Church's figures. I repeat, this shows an average rise of 3.2 mm per year for two decades and no acceleration. A consequence of the lack of acceleration is that if ice melt is making an increasing contribution to that rise, then other factors…

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    3. David Arthur

      resistance gnome

      In reply to Kevin Marshall

      "then much of the rise up to 1950 will be due to natural factors" possibly - yeah: post-glacial thermal expansion that continues throughout warm periods until the next cooling gets underway.

      A look at Holocene temperatures tells us that Holocene peak atmospheric temperatures occurred ~5-6 mllennia ago, and the world was well on track towards the next glaciation when humans struck coal and saved the planet from that fate.

      Sadly, we invented neo-liberalism (which is simply a dressed-up version…

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    4. David Arthur

      resistance gnome

      In reply to Kevin Marshall

      Perhaps we should also consider isostatic rebound - continental crust rises as its icy overburden melts away. This may exacerbate sea level rise at lower latitudes, as earth's crust becomes more spherical with relieving mass loss over the poles.

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    5. Kevin Marshall

      IT Consultant at Engineering

      In reply to David Arthur

      You seem to have a very limited view of political philosophies. "Neo-liberalism" is a derogatory term for the resurgance of classical liberalism of John Locke, Adam Smith and David Ricardo. So-called "robber capitalism" of the USA was an invention of the progressive movement in the late nineteenth century USA.
      When assessing sea level rise, I prefer to look at empirical data rather than colloquial evidence. Like asking elderly people in Britain whether the weather is better or worse, hotter or colder…

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    6. David Arthur

      resistance gnome

      In reply to Kevin Marshall

      Err, it's me who initiated our divergence from the subject of this article, but I can't let that reference to Locke, Smith and Ricardo go without pointing out that their theories are less than ideal if the present circumstance, in which the ongoing environmental and social degradation we see all around the world for the sake of further accumulation of monetary wealth among a pool of super-parasites is the inevitable consequence of following their teachings.

      I think, however, it is your reference…

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    7. Kevin Marshall

      IT Consultant at Engineering

      In reply to David Arthur

      On the classical liberals you offer third hand opinion as fact - an opinion that I have not come across, despite I having studied the history of economic thought as part of my economics degree.
      Similarly, as evidence of you offer an opinion piece by an islander visiting Australia for advocacy training. I prefer the actual evidence. In the 60 years up to 2010 in the South Pacific sea levels have risen by 120mm. Ceteris paribus, the very flat coral islands should have shrunk in size. A geographer…

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    8. Kevin Marshall

      IT Consultant at Engineering

      In reply to David Arthur

      Further on the "sinking" coral islands, you may also recall the article here at the conversation on dynamic atolls by Paul Kench, which found that these low-lying islands rise and fall in line with sea levels.
      https://theconversation.com/dynamic-atolls-give-hope-that-pacific-islands-can-defy-sea-rise-25436
      This is in direct contradiction to the political activist commenting at the Guardian. However, the islands do shift, grow and shrink over time. Along with being exposed to tropical storms, it does make these tropical islands precarious places to live.

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    9. David Arthur

      resistance gnome

      In reply to Kevin Marshall

      "On the classical liberals you offer third hand opinion as fact - an opinion that I have not come across". If you're so sure it's third-hand opinion, then surely you'd have heard of it before?

      In fact my view is not third-hand opinion, it's what I've figured out for myself - as anyone can do when they consider who Locke, Stuart and Ricardo may not have encountered the modern stateless multi-national corporation in all its glory.

      "despite I having studied the history of economic thought as part…

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    10. David Arthur

      resistance gnome

      In reply to Kevin Marshall

      "However, the islands do shift, grow and shrink over time. Along with being exposed to tropical storms, it does make these tropical islands precarious places to live."

      Err, not that precarious - they've been occupied continuously for centuries, in some cases millennia - so the fact that w now have dissemblers trying to tell us that this change isn't rapid says more about the dissemblers than about the world.

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    11. Chris O'Neill

      Retired Way Before 70

      In reply to Kevin Marshall

      "the lack of surface temperature rise in the last 15 years"

      Please stop repeating this global warming denial lie. There was a 92% likelihood of warming in the last 15 years from Gistemp. 92% likelihood of warming does not mean there WAS a lack of warming.

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    12. David Arthur

      resistance gnome

      In reply to Kevin Marshall

      Further on the "sinking" coral islands, you may also recall your high school chemistry, in which the propensity for Calcium Carbonate precipitation from seawater is found to vary with the pH of that sea water. Here's a refresher, albeit from a university: http://courses.washington.edu/pcc588/readings/EH_IV_CarbSys.pdf

      The upshot is, calcifying organisms (eg coral polyps) may not be able to keep up with accelerating sea level rise, particularly as sea water pH decreases.

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    13. Kevin Marshall

      IT Consultant at Engineering

      In reply to Chris O'Neill

      Any calculation of average surface is an opinion, not a fact. Other temperature series (HADCRUT4, UAH, NOAA) show the lack of warming. Even Gistemp shows a lack of warming in the last 10 years. See below.
      The only counter-argument seems to be that every one of the last 4 decades was warmer than the last. Which is a convenient way of covering up a pause.
      http://manicbeancounter.com/2013/09/23/head-of-the-ipcc-rajendra-pachauri-misleads-on-pause-in-global-warming/

      http://www.metoffice.gov.uk/hadobs/hadcrut4/data/current/web_figures/hadcrut4_annual_global.png
      http://www.drroyspencer.com/wp-content/uploads/UAH_LT_1979_thru_April_2014_v5.png
      http://www.ncdc.noaa.gov/sotc/service/global/global-land-ocean-mntp-anom/201101-201112.png
      http://woodfortrees.org/plot/gistemp/from:1984/to:2003/trend/plot/gistemp/from:1984/to:2013/every/plot/gistemp/from:2004/to:2013/trend

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    14. Chris O'Neill

      Retired Way Before 70

      In reply to Kevin Marshall

      "Even Gistemp shows a lack of warming in the last 10 years."

      Sure, anyone can make a cherry-pick with a couple of La Nina years near the end. The error range (±2σ) for the last ten years is ±0.24 degrees C/decade so ten years carries no statistical significance whatsoever.

      Please, in future, don't treat us like idiots.

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    15. Chris O'Neill

      Retired Way Before 70

      In reply to Kevin Marshall

      "Any calculation of average surface is an opinion, not a fact."

      So you think measurements are an opinion, not a fact? Riiiiiiiiiiiiiiiight.

      "Other temperature series (HADCRUT4, UAH, NOAA) show the lack of warming."

      15 years data of HADCRUT4: 87% probability of warming

      15 years data of UAH: 92% probability of warming

      15 years data of NOAA: 85% probability of warming

      So these probabilities of warming mean there WAS a lack of warming, no ifs or buts????????????

      Please, stop treating us like idiots and please, stop spreading global warming denial lies.

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    16. David Arthur

      resistance gnome

      In reply to Kevin Marshall

      "If you disagree with a professor, fine." Err, it's not that I *disagree* with a professor, it's more that the professor is considering only sea level rise, and is hence not looking at sea water changes that are known to adversely affect coral - ocean acidification, and rapid temperature rise.

      It's also worth noting that Prof Kench's example of a coral island that was fine with sea levels 1.5m higher 6 millennia ago is somewhat slower than the ~1m sea level rise anticipated over the next century, let alone the several metres of sea level rise expected thereafter as more polar glaciers undergo the processes now obsrved for Pine Island and Thwaites Glaciers.

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    17. Kevin Marshall

      IT Consultant at Engineering

      In reply to Chris O'Neill

      The your error range does not disprove that the warming has stopped, neither does it disprove evidence of cooling. With accelerating GHG gas levels since the late 1990s (caused by accelerating global emissions) greenhouse gas theory would have
      Now for cherry-picking
      Why chose Gistemp over other data sets? Maybe because it shows the greatest warming trend over the past 40 years and the least warming trend over the 1910 to 1945 period. There there was broadly at least half the warming of 1975-2000…

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    18. Kevin Marshall

      IT Consultant at Engineering

      In reply to Chris O'Neill

      Ultimately a temperature series are an opinion. It might be a very good opinion. but surface based temperatures are based of thousands of thermometers very unevenly dispersed over the planet. There is some estimation, which is why different results are obtained on very similar data sets over the planet.
      Now something in your argument. 87%-92% chance of warming does not mean (a) there has been no warming (b) The median trend is insignificantly different from zero.
      You have mistaken statistics for truth.

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    19. Chris O'Neill

      Retired Way Before 70

      In reply to Kevin Marshall

      "your error range does not disprove that the warming has stopped"

      And you have not proved that it has stopped. In fact no amount of data can disprove that global warming has stopped or indeed even exists. All we have is probability and that probability is rather low, between 8% and 15% depending on the source of data for only 15 years.

      If you want certainty then stop bothering with science because it will never give it to you. I can see that you want certainty that warming is happening.

      "Why chose…

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    20. Kevin Marshall

      IT Consultant at Engineering

      In reply to Kevin Marshall

      Further your dogma, let me give you an analogy,
      I live in Britain, and have huge respect for the British Police, along with the trial by jury system that emerged in Anglo-Saxon England. When the IRA let off bombs in pubs people were justifiably outraged. The police especially, who would want to bring the full weight of the law on the perpetrators. In one case, false confessions were extracted from people wholly innocent. In another case, the clinching evidence was from the hands of the suspects. They had traces of a chemical used in making bombs. The same chemical was found on new playing cards, which a group of Irish workers had been playing.
      In both cases, nobody was going to properly defend "terrorists" in the face of overwhelming evidence. Further, they were Irish, as were the terrorists, and their defense counsel were paid to be biased.The over-turning of the convictions very much undermined people's faith in the police as upholders of the law.

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    21. Chris O'Neill

      Retired Way Before 70

      In reply to Kevin Marshall

      "87%-92% chance of warming does not mean (a) there has been no warming"

      That's what I said. My words "XX% likelihood of warming does not mean there WAS a lack of warming" mean the same thing. You can't even understand the meaning of your own words. The only thing you have achieved is to provide another example of how lacking in cognitive ability those who deny global warming demonstrate themselves to be.

      Thanks for the demonstration. In a way it's reassuring when you demonstrate your appalling incompetence.

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  4. Ray Butler

    logged in via Facebook

    I think action on climate change may reduce the rate of change but I doubt it will stop change, we cannot stop polluting all together and even if we could it would take time for the planet to recover, hence take time for the momentum to come off the rate.

    But another thing I like to add is that swells behave on the pull of the moon; the more water we have in the oceans will likely mean swells are larger as the moon has more to transfer energy on to. So tides will go higher and waves will wash up the shore higher.

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  5. Kevin Marshall

    IT Consultant at Engineering

    I have done some research on the prediction of 1.25 to 2m sea level rise by 2100.
    - It top slices the NOAA prediction of 2012.
    - It is way beyond the UNIPCC's most extreme prediction of Sept 2013.
    - Ignores the UNIPCC's expression of low confidence in any predictions above 1 metre.
    - Is based on extreme melting of the polar ice caps, which latest research repudiates.
    - Is similar to predictions made by Professor Wanless in 2008.
    Despite six years of contradictions, the Professor is still expressing the same extremist beliefs.
    http://manicbeancounter.com/2014/06/01/sea-level-rise-extremism-of-professor-wanless-and-possible-consequences-for-miami-dade/

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