From the Scientific Urban Legend Department: ‘AGW Sea Level Rise Made Sandy More Destructive’

Guest essay by Kip Hansen, St Thomas, USVI

The Claim:

Even if research shows that Hurricane Sandy was not “caused” by Global Warming, it is certain that sea level rise caused by anthropogenic global warming increased the resultant destruction from Sandy’s storm surge.

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Example:

“ … sea levels continue to rise due to global warming. The picture here is very clear. And that means that every single hurricane that hits land will push seawater farther inland when it does so. Or as one scientist told me in the wake of Sandy, “There is 100 percent certainty that sea level rise made this worse. Period.” “ (footnote 1)

“Climate Change Made Sandy Worse. Period.” (footnote 7)

Background:  

From the New York State Sea Level Rise Task Force Report to the Legislature (2010) — “Sea Level Rise–Causes and Projections : Local sea levels are affected by ocean currents, gravitational forces, prevailing winds, and rise and fall of the land mass. Within the coastal regions of New York State, the land mass is slowly sinking, with the exception of the Hudson estuary north of Kingston. This movement is a result of geological forces and impacts of human activity and development. It affects local, or relative, rates of sea level rise. “

“These projections are supported by empirical data documenting recent sea level rise in New York State. For example, gauges at the New York City Battery indicate that sea level in the 2000s is 4 to 6 inches higher than in the early 1960s” (footnote 8)

“Storm surge in the NYC–LI area can result from tropical storms and extratropical cycles. Hurricanes have directly hit NYC (Scileppi and Donnelly 2007), such as on 3 September 1821 (Ludlum 1963) and 25 August 1893 (National Hurricane Center 2008). The category-3 ( ; 110 kt; 1 kt ’ 0.5 m s 2 1 ) winds during the 1821 event flooded a large portion of southern Manhattan (Ludlum 1963), but at that time the NYC population was only ; 150 000. There have been no other direct hits by major hurricanes (greater than category 2) across NYC–LI since the 1938 ‘‘Long Island Express’’ (National Hurricane Center 2008). Hurricane Gloria (1985) was originally labeled as category 3 at landfall for Long Island but has since been reanalyzed as category 1 (C. Landsea 2008, personal communication). However, it is only a matter of time before another major hurricane will impact the NYC–LI area. “ (This statement proved to be prophetic – Hurricane Sandy hit NJ/NY on 29 October 2012)

“Sea level along New York’s coast has been rising at the rate of almost one foot per century for at least 100 years” (footnote 3)

(footnote 2 – the above four quotes are all from NYS Sea Level Risk Task Force Report to the Legislature 2010)

“The mean sea level trend [at the Battery, Manhattan Island, NY] is 2.77 millimeters/year with a 95% confidence interval of +/- 0.09 mm/yr based on monthly mean sea level data from 1856 to 2006 which is equivalent to a change of 0.91 feet in 100 years.” (footnote 6)

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(footnote 10)

The following NOAA graphic shows the current trend of sea level rise for the Battery at 0-3 mm/yr, based on this same tide gauge.

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This is in agreement with the Battery’s tide gauge long-term trend of 2.77 mm/yr both by data from NOAA and from Leatherman 1995.

Overall Global Sea Level Rise (Douglas 1991) gives 1.8 mm/yr for the 100 year trend, 1880 – 1980, based on Tide Gauges. This figure is generally accepted throughout the field, for example, Church and White found 1.7 mm/yr for 1870 – 2004 (footnote 5) [one sees figures ranging from 1.45 mm/yr to 1.8 mm/yr (1870-2004) based on tide gauges, and 2.9 to 3.4 mm/yr, based on the still short satellite data series (1993-2003)]. (footnote 11)

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We can now look back now to the causes section of the NYS Sea Level Rise Task Force Report which told us that one factor in sea level change is “rise and fall of the land mass” – which refers both to normal subsidence (in which land sinks for some immediate cause – such as settling of coastal areas created by fill as has been reported recently in Norfolk, VA) and to Glacial Isostatic Adjustment (GIA), which is “Post-glacial rebound (sometimes called continental rebound, glacial isostasy, glacial isostatic adjustment) … the rise of land masses that were depressed by the huge weight of ice sheets during the last glacial period” (footnote 9).

The NYSSLRTF Report quoted above stated clearly that “Within the coastal regions of New York State, the land mass is slowly sinking”. But by how much? In his seminal 2007 paper on North American Glacial Isostatic Adjustment, which was based on GPS data, Giovanni Sella states “The uplift rates generally decrease with distance from Hudson Bay and change to subsidence (1 – 2 mm/yr) south of the Great Lakes. “ (footnote 4) In plain English, the coastal areas of New York, including NY City, much of coastal New England and areas to the south are sinking at a rate ranging from 1 to 2 mm/yr due to the effects of GIA. To be clear here, while GIA normally refers to land masses rising, in the area concerned, coastal NY, GIA has caused the local land mass to subside or sink.

Assumptions for Analysis:

None of the numbers — facts and figures — contained in the quotes above are controversial — they represent the mainstream views on sea level rise and GIA subsidence, both qualitatively and quantitatively, in the area of concern, New York State, and certainly apply to New York City and surrounds as affected by Hurricane Sandy.

All quoted figures are referenced in footnotes (linked directly to source materials where possible) and come from open source (non-pay-walled) peer-reviewed journal papers and government agency web sites.

I take it as a given that, for the purposes of this discussion, we can all agree that sea level change is an entirely LOCAL issue. Hurricane Sandy’s storm surge and resulting damages therefrom depend ONLY on local sea levels relative to local land mass. NY City’s tunnels were not flooded by any putative sea level rise in Sydney, Australia or the South Sea Islands. (There is another discussion about Global Sea Levels, but this is not it.)

This is a common sense, rough-estimate hypothesis-testing exercise, not a proof of anything – so we only need reasonably accurate and readily agreed upon approximations. Therefore, for our “back of the envelope” calculations, I will use the following:

a) Time period = 50 years (1960-2010) – because this is the time period used by the NY State SLR Task Force (footnote 2)

b) For relative sea level rise in NY City, I will use NYSSLRTF 2010’s “4 to 6 inches higher than in the early 1960s”. (footnote 2) This is the same (+/-) as the tide gauge data from NOAA for the Battery, Manhattan Island, NY. It is the longest tide gauge time series in the US — beginning in 1856 and running to the present day. (footnote 6) (footnote 10)

c) For Global sea level rise, I will use Church and White’s 1.7 mm/yr as it covers 1870 – 2004 (Douglas 1991 found 1.8 mm/yr for 1880- 1980). (footnote 5)

d) For subsidence at NY City, I will use the mean of 1.5 mm/yr but give as range extremes both 1 and 2 mm/yr. (footnote 4)

The following section gives the elementary school level mathematics (addition, subtraction, multiplication, and division only – no statistical methods or analysis).

Calculations:

Start with NYSSLRTF’s “at the New York City Battery indicate that sea level in the 2000s is 4 to 6 inches higher than in the early 1960s.” As our other numerical quantities are all in millimeters, as is common in science, we will use these numbers: 4 inches = 101.6 mm (let’s use 100 for ease…it changes nothing). 6 inches = 152.4 mm (let’s use 150, same reason) , the mean is 5 inches which is 127 mm (we’ll use 125). Note that this is well within keeping with NOAAs trend of 2.77 mm/yr for the entire length of the Battery’s tide gauge record.

NYSSLRTF’s stated sea level change at the Battery, 1960-2010, is in mm:

plus 125 mm. (mean of 100 to 150). Note that this is approximately 2.5 mm/yr over the 50 year period. If we were to increase this figure to 138 mm, it would agree precisely with NOAAs 2.77 mm/yr—instead we use the figures from the NYSSLRTF Report for consistency.

For subsidence take 1.5 mm/year (halfway between 1 and 2 mm/yr) times 50 years == 75 mm or 2.95 inches of subsidence. This number has a negative sign, as it is land sinking (as opposed to the sea rising). The Battery has apparently sunk approximately 3 inches since the 1960s.

As the New York State Sea Level Rise Task Force has estimated that “sea level in the 2000s is 4 to 6 inches higher than in the early 1960s” and we find that approximately 75 mm or 2.95 inches of that was due to the land sinking (GIA effects only — nothing included here for subsidence caused by the settling of land created by fill), that leaves us with:

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Or, in pictures: (footnote 12)

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To cover all the bases, let’s include a grid of both variables, Relative SLR and GIA:

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This grid shows that the mean value (highlighted) at about 2” of absolute sea surface rise over our 50 year time period at the Battery.

Then using the long term, pre-AWG 100-year trend for Global Sea Level Rise of 1.7 mm/yr, we would expect, for 50 years (1960-2010): 50 times 1.7 mm = 85 mm (or 3.35 inches) of sea level rise due to this inexorable rise of the sea as the world works its way out of the last ice age

Subtracting the expected geologically-caused sea level rise from the actual sea level rise experienced should result in a remainder that would be the portion of the absolute sea level rise that could be attributed to recent Anthropogenic Global Warming.

Thus we now can calculate:

plus 50 mm attributable to rising sea level minus 85 mm expected from long-term general worldwide sea level trends equals minus 35 mm or 1.37 inches less than expected from the geologically-caused sea level rise trend, leaving less than nothing to be attributed to AGW-induced sea level rise.

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All of this in pictures:

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Using our grid of two variables:

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Note that only under the Highest Relative SLR/Lowest Subsidence Rate scenario does this result even become positive – and then only by 15 mm/0.6 inches.

This brings us the somewhat surprising conclusion that the relative sea level change at the Battery in NYC which can be attributed to Anthropogenic Global Warming (by any of its commonly used names) is probably less than zero and certainly not significant. Rather, sea level change at the Battery, when calculating with the means of the variable ranges, is approximately 35 mm less than would be normally expected if the sea level change at the Battery was simply following the long-term slow and gradual rise seen to have begun worldwide at least 150 years ago (long before AGW is posited to have begun). It is not suspected that AGW caused this deficit.

Summary:

At the Battery, Manhattan, NYC over the period 1960-2010, we found less than zero mm/inches of sea level rise to be attributed to post-1960 AGW. With admittedly rough calculations, it appears that NY City has seen “4 to 6 inches” – 100 to 150 mm — of sea level change over the last 50 years, which is approximately equivalent to “8 inches in 100 years”, but over 3 inches — 85 mm of the relative change — was due to subsidence (land sinking) as a result of GIA. Subtracting the subsidence from the relative rise leaves only 2 inches — 50 mm –of rise attributable to the sea actually getting higher – which is less than the 3.3 inches — 85 mm — which would be expected from long-term pre-AGW (150 year) worldwide positive sea level rise trends, the trend agreed by all not caused by AGW, but attributed to geological causes, usually to the ocean water warming and expanding after the end of the last Ice Age.

Bottom Line:

The claim is a “Scientific Urban Legend” – made up of the TRUE and obvious fact that any positive change in local average relative sea level will make any storm surge “worse” – by the simple effect of the relative water level being higher by whatever amount — blended with the FALSE assumption/assertion that some or all of the oft cited 8 inches of Global Sea Level rise over the last 100 years had actually taken place in or around NY City and that this sea level rise had been caused by Anthropogenic Global Warming.

At the Battery, Manhattan, NYC, there has been, so far, no significant sea level rise attributable to AGW. Period. Therefore, it is extremely unlikely that AGW-induced sea level rise contributed in any real world sense to the destruction caused by Hurricane Sandy’s storm surge.

 

EPILOGUE:

None of the above means that NY City and surrounding areas should quit worrying about sea level rise. The sea is rising, has been rising, and will continue to rise. The coastal areas of NY and NJ are sinking and will continue to sink. Both of these conditions will continue until geological conditions change to stop them—perhaps in millennia. The recent warming of the atmosphere may yet cause discernible additional sea level rise at the Battery. NY/NJ should plan for a continued sea level rise range of 1.7-2.8 mm/yr for the foreseeable future and take positive steps to mitigate the known dangers. So far, it simply has had nothing to do with AGW.

 

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1 Here Comes the Story of No Hurricanes by Chris Mooney | Fri Sep. 6, 2013 6:55 AM PDT

http://www.motherjones.com/environment/2013/09/hurricane-season-ipcc-sandy

2 – New York State Sea Level Rise Task Force Report to the Legislature — Dec 31, 2010 http://www.dec.ny.gov/docs/administration_pdf/slrtffinalrep.pdf

3 – NYS Sea Level Rise Task Force Report 2010 cited this to:

Leatherman, S.P., R Chalfont, E. Pendleton, S. Funderbunk and T. McCandless. 1995. Vanishing Lands , Sea Level, Society, and Chesapeake Bay. Univ. of Maryland Laboratory for Coastal Research & US Fish and Wildlife Service Chesapeake Bay Field Office

http://www.fws.gov/slamm/vanishinglandssealevelsocietyandchesapeakebay2.pdf

4 – Observation of glacial isostatic adjustment in ‘‘stable’’ North America with GPS — Sella et al GEOPHYSICAL RESEARCH LETTERS, VOL. 34, L02306, doi:10.1029/2006GL027081, 2007

http://www.ngs.noaa.gov/CORS/Articles/2006GL027081.pdf

5 – http://users.coastal.ufl.edu/~arnoldo/ocp6050/homeworks/douglas91.pdf also “A 20th century acceleration in global sea-level rise” Church and White 2006 http://naturescapebroward.com/NaturalResources/ClimateChange/Documents/GRL_Church_White_2006_024826.pdf

6 – data from NOAA http://tidesandcurrents.noaa.gov/sltrends/msltrendstable.htm

text from http://reason.com/blog/2012/11/01/hurricane-sandy-and-sea-level-rise-in-ne

7 – “Climate Change Made Sandy Worse. Period.” —By Chris Mooney | Thu Nov. 8, 2012 http://www.motherjones.com/environment/2012/11/climate-change-made-sandy-worse-period The scientist that makes most of the sea level claims is Dr. Ben Strauss who “holds a Ph.D. in Ecology and Evolutionary Biology from Princeton University, an M.S. in Zoology from the University of Washington, and a B.A. in Biology from Yale University” and is a paid employee of Climate Central, a AGW advocacy organization.

8 – NYSSRLTF Report cited this as:

Colle, B.A., K. Rojowsky, and F. Buonaiuto. 2010. New York City storm surges: Climatology and an analysis of the wind and cyclone evolution. Journal of Applied Meteorology and Climatology 49 : 85 – 100. Pub ID# 3772

http://journals.ametsoc.org/doi/pdf/10.1175/2009JAMC2189.1

9 – Definition from the Wiki:

https://en.wikipedia.org/wiki/Post-glacial_rebound

10 – The NOAA reported sea level trends at http://tidesandcurrents.noaa.gov/sltrends/msltrendstable.htm and in the graph at

http://tidesandcurrents.noaa.gov/sltrends/sltrends_station.shtml?stnid=8518750

are relative sea levels – where the sea surface is in relation to a certain point on the land mass. There are no adjustments made, as they would be irrelevant. So, in plain English, the relative sea level change is the sea surface movement (up or down) plus the land mass movement (up or down). This is the sea level change you would see with your eyes if you were there.

11 – Although Church and White arrived at a figure of 1.77 mm/yr, CSIRO cites Church 2011 for uncertainty bars but states that the graph shown indicates “an average rate of rise of about 1.6 mm/yr over the 20th Century” rather than Church’s finding of 1.77 mm/yr. http://www.cmar.csiro.au/sealevel/sl_hist_few_hundred.html

12 – For our cartoon pictures, we assume that the US Geological Survey Team installed a brass reference marker at the 1960 Mean Sea Level position on our imaginary sea wall at the Battery and placed a reference tide gauge marked in inches alongside, all for our convenience.

13 – h/t for the format of this article to snopes.com

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73 thoughts on “From the Scientific Urban Legend Department: ‘AGW Sea Level Rise Made Sandy More Destructive’

  1. I think an obvious omission to your calculations is the effect of the stone, steel, concrete, glass glacier that has been growing, particularly during the 20th Century over Manhattan. How much does a building weigh? I think this would be a fascinating calculation and it could be extrapolated to all coastal cities of any size. Its materials are about 2.5 times the weight of ice. Possibly an ultra precise level survey between cities along a coast would show a small amount of sinking centred on cities

  2. Regardless of subsistence and other geological changes, flooding has to be worse with additional sea level rise. Logic.

  3. you have got to let the alarmists give us something to laugh at. Sea level is one of many laughable bloomers.

  4. Yes, but if global warming is not to blame, that would mean that the politicians had failed to prepare properly for an otherwise predictable event………………………………..oh!

  5. As an engineer working in NYC, often for NYC clients, I am happy to see this urban legend dissected so thoroughly. I’ve been aware of the sea level rise in NYC due to tectonic rebound for more than twenty years, and the claims made regarding Sandy and AGW induced SLR are absurd. Your many references to publications are welcome as well!

  6. Pippen Kool says: “Logic.”

    It may be logic, but it also misses the point of this article by a country mile.

    Care to try again?

  7. Long Beach Island New Jersey, where I use to summer as a boy, was hit badly by Sandy and lot of people blame AGW. But they seem to forget the 1962 Ash Wednesday Storm which was much more destructive all up the Eastern seaboard. The Ash Wednesday Storm cut the island in a few places, Sandy did not. Selective memory play a big part as the above article shows.

    The Ash Wednesday Storm: “In New Jersey alone, an estimated 45,000 homes were destroyed or greatly damaged. In New York, on Long Island, communities such as Fire Island were decimated; 100 homes there were destroyed. Wave heights reached 12 m (40 ft) by the shore of New York City.”

    I have never seen this storm mentioned in any article talking about Sandy including on this web page. It should be.

    http://en.wikipedia.org/wiki/Ash_Wednesday_Storm_of_1962

  8. If you mix enough different start dates and pick your estimates of subsidence and glacial rebound rates carefully I suppose it may be possible to elide the 250mm or ~10 inches of global rise in see level during the last century into insignificance.

    But the reality is that the local sea level rise is always a combination of the global rise and the much smaller local effects. Any rise in sea level that is greater than or less than the ten onches from AGW is due to local factors.
    But local factors only modify the global rise, not replace it.

  9. Kip: I believe you may be confusing the issue of local sea level rise (SLR) and global SLR. Global SLR is caused by the expansion of warmer ocean water and the melting of ice caps and glaciers. Global SLR is modified in different places such as NYC by GIA and other geological changes and by changes in winds and air pressure. (The AMO may have an impact tide gauges.) The appropriate measure of how much global warming contributed to global SLR is an appropriate measure of how much climate change contributed to Sandy. Of course, it is hard to separate SLR in the first half of the century (presumably caused mostly be the end of the LIA) from anthropogenic SLR mostly in the second half of the century. So I’d say anthropogenic climate change contributed about 6 inches, which IS minimal given a storm surge of about 10 feet.

    We don’t know when sea level began rising at the Battery at the rate shown on your graph, but it probably began with the end of the LIA. We are certain that SLR hasn’t been occurring at this rate for the last millennium; a SLR of roughly 10 feet over this period would be known. Sea level probably dropped some during the LIA, but geological changes in coast lines make it difficult to measure changes over millennia. The SLR seen around 1900 was natural and not caused by GHGs, but this amount of SLR isn’t a “normal” variation that persists for millennia. It is caused by climate change: the end of the LIA, the end of an ice age, or anthropogenic climate change.

  10. Pippen Kool says:
    September 19, 2013 at 6:31 am (Edit)
    Regardless of subsistence and other geological changes, flooding has to be worse with additional sea level rise. Logic.

    ————————————————————-

    Quite. However reading the article it seems that any AGW contribution was negligible. This seems to be the case so often with Man Made CO2, the effects are trivial.

  11. Reply to Gary Pearce: Yes, you are absolutely correct — there may be additional subsidence due to both development and the fact that much of Manhattan is built on fill –> see Freaking out about NYC sea level rise is easy to do when you don’t pay attention to historyat http://preview.tinyurl.com/kg3pz8u . Much of the central spine of Manhattan Island is solid bedrock, however. Much of Sandy’s damage was done in areas of Statan Island and Long Island, where neighborhoods had been built on what are essentially (historical) mudflats.

    Reply to Pippen Kool: Yes, correct. That is the true part “…. the TRUE and obvious fact that any positive change in local average relative sea level will make any storm surge “worse” – by the simple effect of the relative water level being higher by whatever amount.”

    Reply to Lichanos: Thank you. Perhaps you know of some more current research, using modern highly accurate GPS data, for subsidence specifically in and around NYC?

  12. Wasn’t the max swell caused by storm swell plus 20 year exceptional (predictable) high tide about 13 ft?
    And they write a paper about 35 mm ?
    “AGW certainly made it worse. ” Deception by omission.

    WTF, period.

  13. Pippen Kool says:
    September 19, 2013 at 6:31 am

    That’s correct. But exactly how would one differentiate between ‘extra’ flooding caused by a high tide in conjunction with a storm arrival?, and then of course, the wind (speed) driven issue?, etc, etc.
    It is indeed logical to suggest that a few inches of general sea level rise would contribute to an overall increased flooding risk – but that increase in risk is relatively insignificant compared to the actual natural sea level tidal variation and timing thereof (i.e. spring or neap tides) coupled with the natural wind speed and storm actual passage time duration, rainfall, etc, etc. Obviously a storm arriving during a low tide would have far less flood risk than one arriving just at high tide. In the context of tidal variation a 10ft tidal level change being altered by a few inches is not really going to be significant in terms of the other factors involved. We see forecasts where they concentrate on when high tide is due as well as the storm arrival/passage, wind speeds and rainfall?
    In the context of a storm driven sea (as being the case here) – a few inches of general sea level rise is somewhat moot as a major contribution IMHO. (Think of big waves crashing down in a storm, and you’ll get the picture)
    Put it another way, are the flood defences designed on MHWL or MHWL plus storm surge? If you agree it is the latter, and you agree that we have probably not observed or ‘recorded’ the worst storm ever (think about it) – how would you design your flood defenses? You cannot possibly add in all the variables to ensure no flooding. Typically, assumptions like 100 year events, and max wind/tides can be used to ESTIMATE design requirements. On an actual, real life, say, 10 to 15 foot storm surge, how much do you think a few inches of general sea level rise is gonna make to the final outcome of your design???

  14. Reply to Frank (September 19, 2013 at 7:15 am): This article is about LOCAL RELATIVE sea level rise — measured at the Battery. See the NOAA graph at http://tidesandcurrents.noaa.gov/sltrends/sltrends_station.shtml?stnid=8518750 which clearly shows the relative SLR at the Battery, since 1856, both numerically and graphically. There is no physical or logical reason to assume that local relative SLR, at the Battery, from 1890-1960 is caused by recovery from the Little Ice Age, or the last real ice age, and SLR from 1960-2010 is caused by AGW. There is no reason to believe that the long-term trend prior to 1960, a geological phenomena, should stop and AGW take over.

    Your “I’d say anthropogenic climate change contributed about 6 inches” would be 100% (or more) of the SLR at the Battery for 1960-2010 according to the New York State Sea Level Task Force Report to the Legislature (2010).

    Reply to Jimbo (September 19, 2013 at 7:16 am): It is Battery Park that is entirely landfill. Much of the periphery of Manhattan is landfill. See the animation at http://wattsupwiththat.files.wordpress.com/2010/11/nyc_manhattan_sl_animation.gif .

  15. I should add as a supplement to my previous post – that of course, it follows that any sea level rise (even if caused by AGW) is inconsequential at the scales we are talking about – and any direct blame on AGW for the flooding is somewhat crass! Maybe in a few hundred years time, when sea levels are another few feet higher we could objectively point the finger – BUT only if we can say that SLR is due to AGW in the first place – which we can’t !!

  16. Reply to izen (September 19, 2013 at 7:09 am): This article is about Local Relative Sea Level at the Battery, Manhattan, NYC. There are many discussions about Global SLR, but this is not one of them. Nonetheless, perhaps you could share with us your source for this: “the ten inches [of global SLR] from AGW”.

  17. Your Title “Mixture Of True And False Information” and the example given
    Example:
    “ … sea levels continue to rise due to global warming. The picture here is very clear. And that means that every single hurricane that hits land will push seawater farther inland when it does so. Or as one scientist told me in the wake of Sandy, “There is 100 percent certainty that sea level rise made this worse. Period.” “
    This is another of classical propaganda methods being used by parties interested in promoting global warming. Another blog listed 22 commonly used techniques, this is technique number 3.
    3. Misinformation. This works best if you are subtle but the main idea is to twist information to your own ends. A common use of this is in movie advertising, where if the movie is a real dog, publicists can selectively take positive comments from bad reviews and create the illusion that the film is better than it actually is. This sort of thing can land you in court with well-financed reviewers but twisting information to better suit your goals works if you can do it convincingly and not get caught by publicists or lawyers.
    The 22 techniques are here http:/www.strategypage.com/htmw/htiw/articles/20130826.aspx

  18. This is an excellent article that documents the relative sea level to adjoining land mass.

    Regarding Sandy which was not a Hurricane when it struck New Jersey, the reason there was so much flooding is that the area was already flooded due to a lingering North East Storm and Sandy lingered more than most Hurricanes and piled more coastal waters on top of an already flooded region.
    It disturbs me that those who are hawking the mantra of more frequent and more severe storms ignore the fact that Sandy was piled on top of a lingering NE storm. In fact some of the worst storms causing flooding and coastal damage have been NE Storms probably because they linger and push water ashore day after day. The details of the 1962 NE storm are outlined below

    http://njmonthly.com/articles/lifestyle/storm-warning.html

    “What made it so spectacular was its very slow pace, a strong storm moving slowly up the coast with a persistent onshore flow of winds from the Northeast,” says Robinson. “What that did was just push water up toward the coast and into the back bays and onto the beaches. Before it could all drain out, there was another high-tidal event. It was like putting a fan in your bathtub and pushing the water all in one direction for three days.”

    “While towns from Sandy Hook to Cape May had damage, the worst havoc seemed to befall LBI, which for a time split into three pieces—freshly carved inlets rushing from Barnegat Bay to the ocean in Harvey Cedars in the north and Holgate in the south. Margaret Buckholtz is still amazed at what she saw when she reached the island to check on her father as the storm was finally subsiding on its third day.”

    Sandy came on top of a similar storm.

  19. Jimbo [September 19, 2013 at 7:16 am] says:

    I read that New York Battery is a landfill. Does this make subsidence worse?

    Not just Battery Park City, pretty much everything that touches water. And not just NYC, but in cities all around the World.

    Makes you wonder just how they go about measuring sea level from a major city keeping a straight face.

  20. Sandy was not a hurricane at landfall. Catcracking is correct.
    The National Hurricane Center reports wind speeds estimated from aircraft.
    Aircraft over-estimate the surface wind speeds. The NHC has developed a tendency to emphasize “gust” speeds. Hurricane speeds are not defined by “gusts” but by sustained surface speeds.

    Actual sustained wind speeds measured by surface stations and offshore buoys all show that maximum sustained winds at the peak of Sandy were 25 meters per second at two offshore buoys. Land speeds were less. The threshold defining hurricane winds is 33 meters per second. Most of the sustained wind speeds along the coast show data of about 20 meters per second.

    Photos and video of the storm show damage consistent with wind speeds of a tropica storm of winds at 20 meters per second. Tidal surge caused most of the damage reported by the hysterical media.

    This has happened before, the NHC over-estimated the winds speeds of Isaac. Actual data recorded by surface stations and off-shore buoys show that Isaac was not a hurricane at landfall.
    Anyone can see the data recorded by off-shore buoys by going to the NDBC website.

  21. Off topic, admittedly, but referring to the ‘Example’ above, why do Americans say “Period” to end some sentences. The sentence itself should indicate that no more needs to be said (if required). See how better the ‘examples’ look…
    “There is 100 percent certainty that sea level rise made this worse.”
    “Climate Change Made Sandy Worse.”

    The term ‘Period’ is redundant. It adds nothing to the sentences and is therefore superfluous. Sorry, but the English do find it quite annoying.

  22. Thanks to Kip Hansen and Blade for the link below showing Battery Park and its nearby areas. It makes me wonder about proper compaction when the area was filled in with soil. Just a thought.

  23. Reply to The Ghost Of Big Jim Cooley (September 19, 2013 at 8:49 am):

    from the Dictionary of American Slang and Colloquial Expressions. http://dictionary.reference.com/browse/Period!

    Period! definition

    exclam.
    . . . and that’s final! (A way of indicating that there will be no more discussion or negotiation.) : “My final offer is $30. Period!”

    My use of “Period.” derives from Mooney’s (Strauss’s?) original use. Ain’t language fun?!?

  24. The CSIRO chart is scientifically invalid. The tide gauge and satellite altimeter sea level rise data are two completely independent measurement systems. There is no common terrestrial reference frame allowing these measurements to be stitched together in a comparison as shown in the CSIRO chart. Tide gauge data actually measure land elevation movement of sea level while satellite data measure an ocean volume proxy.
    Making such comparisons is equivalent to stitching instrument temperature records onto palo-climate temperature records. NASA JPL has proposed a new satellite program in the future to address the many complexities in trying to relate satellite and tide gauge data measurements to each other but we are many years away from being able to make such comparisons reliably. Additionally the tide gauge data on the CSIRO chart is misleading as a measure of global sea level rise because the instruments used to make this chart include data from many tide gauge records which are too short in duration and do not allow for the long period multi-decadal ocean cycles to be properly reflected. Thus the CSIRO tide gauge portion of the chart over states the rate of sea level rise.
    The satellite altimeter data is also far too short in duration to be used to characterize the rate of sea level rise because of the long period ocean cycle behavior. Additionally the three different satellite records used to create the overall satellite record all show inconsistencies between their individual records and the reasons for these differences are not yet fully understood.
    The most accurate measure of sea level rise available is NOAA tide gauge data for instruments with 60 years or more of measurement data. Using these instruments show a sea level rise of of less than 1.8 mm/year over the last 80 or more years with no acceleration in sea level rise at all in this record.

  25. Kip Hansen says:

    September 19, 2013 at 7:23 am
    “Reply to Lichanos: Thank you. Perhaps you know of some more current research, using modern highly accurate GPS data, for subsidence specifically in and around NYC?”
    ===========================
    Kip, GPS is not accurate enough (yet) to make highly accurate elevation measurements,
    that is why these are still big sellers:

    http://www.mohaveinstrument.com/NewFiles/BarcodeRod.html

    Just a note from a re-tired surveyor :)
    (Last I heard you can get within 1/4″ horizontal, but 2-3 times less accurate in the vertical solutions.
    Maybe someone can elaborate on this ?).

  26. No time to really analyze this right now although I don’t see any obvious problems
    Two qubbles.
    1. The Battery tidal gauge isn’t the oldest in the US. Somewhat surprisingly, the oldest is at San Francisco. It was put into service in 1854
    2. Contrary to common belief, Topex-poseidon is not the only satellite project to measure sea level. In particular ERS came up with a sea level rise of — as I recall — 2.0 mm per year (close to the tidal gauge value) but with broad error bands due to lack of faith in commonly used ionospheric delay models. (Topex-poseidon has a different and quite possibly superior method of determining ionospheric delays in the Radar Altimeter signal).
    =====
    Gary Pearse — It’s not impossible that the infrastructure on Manhattan is depressing the island some, however, it is worth pointing out that the skyscrapers are anchored in Ordovician Age Manhattan Schist which looks to be an extraordinarily uncompressable rock.

  27. Reply to u.k.(us) (September 19, 2013 at 9:13 am): “GPS is not accurate enough (yet) to make highly accurate elevation measurements”

    You are correct as long as you are talking about standard end-user equipment – hand-held, automotive, and standard navigational GPS equipment. To make the kinds of measurements necessary to determine both vertical and horizontal movements of land masses, accurate to the millimeter level necessary to determine GIA and fault movement for example, geologists use a continuously operating high accuracy GPS, like those being installed by the National Geodetic Survey in the CORS project — http://www.ngs.noaa.gov/CORS/ .

    For more information you can see:

    NOAA Improves GPS Accuracy

    http://www.noaa.gov/features/earthobs_0508/cors.html

    and/or

    Cutting Edge GPS Science Applications by Stephen M. Lichten, Deputy Manager Communications, Tracking and Radar Division (33)
    JLP, CalTech, December 2008 http://www.oosa.unvienna.org/pdf/icg/2008/icg3/22.pdf

  28. Reply to Don K (September 19, 2013 at 9:41 am): “…the oldest is at San Francisco. It was put into service in 1854″

    Don, you are absolutely right, according to 2004: 150th Anniversary of the San Francisco Tide Gauge (at http://oceanservice.noaa.gov/topics/navops/ports/supp_sanfran_tidegage.html ) “On June 30, 1854, the United States Coast Survey, the oldest federal scientific agency, installed a self-recording tide gauge in San Francisco Bay.”

    However, the helpful folks at Tides and Currents at NOAA, show the San Francisco, California sea level trend for SF, CA starting only in 1897 (see chart at http://tidesandcurrents.noaa.gov/sltrends/msltrendstable.htm ).

    What appears to be the explanation can be found at this graphic chart: http://tidesandcurrents.noaa.gov/sltrends/sltrends_station.shtml?stnid=9414290%20San%20Francisco,%20CA which shows that the tide gauge used by NOAA shifted somehow (possibly location, possibly something else) in 1897, making the continuous record only reliably available from then, instead of the earlier date.

    I will leave discussion of the measurements of Global SLR to others.

  29. izen says:

    September 19, 2013 at 7:09 am

    “…the ten onches from AGW…”

    Citation please. Your 10″ is more than the approx. 225 mm show in the GMSL graph at the top of the post. I think like most men you exaggerate.

  30. Reply to bw (September 19, 2013 at 8:48 am): “Sandy was not a hurricane at landfall.”

    You are technically correct. I use the title “Hurricane Sandy” as it is the common name for this event, for the same reason WUWT tags this article under Hurricane Sandy. If this were a discussion on hurricanes or hurricane strengths and frequencies, I would have made the technically correct distinction.

    It is important for readers to realize that this storm was just a big tropical storm that pushed a lot of water–storm surge–into NY Harbor and surrounding areas at the time coinciding with an extremely high tide. (see http://www.usatoday.com/story/tech/sciencefair/2012/10/29/sandy-full-moon-tide/1666479/ )

    Had Sandy brought hurricane force winds, especially Force 3 or higher, the damages might have been not just disastrous, but horrific. If there are hurricane scientists reading here — maybe you could weigh in on “What if Sandy had been a Force 4/5 hurricane?”

  31. Climate Change Made Sandy Worse. Period.

    You expect headlines like that from moonbats like the appropriately-named Chris Mooney, but what about those proffered by “legitimate” climate scientists?

    New analyses find evidence of human-caused climate change in half of the 12 extreme weather and climate events analyzed from 2012

    In that press release regarding their report, they say this about SuperDuperDeluxeStorm Sandy:

    However, climate-change related increases in sea level have nearly doubled today’s annual probability of a Sandy-level flood recurrence as compared to 1950. Ongoing natural and human-induced forcing of sea level ensures that Sandy-level inundation events will occur more frequently in the future from storms with less intensity and lower storm surge than Sandy.

    Urban legend or not, they will not be letting go of the Weather Extreme meme any time in the near future as I noted in my blog posts the other day. If anything, I imagine the claims will get more “extreme” as the desperation to keep this CAGW shell game afloat reaches its climax. By the way you gotta love the picture in Mooney’s article directly under the head. The one word seen in the picture describes his article perfectly: WRONG.

  32. Kip Hansen says:

    September 19, 2013 at 9:41 am

    “To make the kinds of measurements necessary to determine both vertical and horizontal movements of land masses, accurate to the millimeter level necessary to determine GIA and fault movement for example, geologists use a continuously operating high accuracy GPS, like those being installed by the National Geodetic Survey in the CORS project — http://www.ngs.noaa.gov/CORS/ . ”
    ============================
    But, here is an excerpt from the link (they talk of approaching centimeters):
    “CORS enhanced post-processed coordinates approach a few centimeters relative to the National Spatial Reference System, both horizontally and vertically.”

    Yet, we are trying to find millimeters of sea level rise.
    I don’t think GPS is accurate enough yet.
    Just say’n.

  33. Reply to galileonardo (September 19, 2013 at 10:56 am): “You expect headlines like that from moonbats like the appropriately-named Chris Mooney, but what about those proffered by “legitimate” climate scientists?”

    Luckily, I have written only about one aspect of a single event.

    There have been many online discussions and criticisms to the report “Explaining Extreme Events of 2012 from a Climate Perspective” released by the Bulletin of the American Meteorological Society (available at http://www.ametsoc.org/2012extremeeventsclimate.pdf )

    Andy Revkin weighed in, mostly positively, with this Assessing the Role of Global Warming in Extreme Weather of 2012
    http://dotearth.blogs.nytimes.com/2013/09/06/assessing-the-role-of-global-warming-in-extreme-weather-of-2012/ .

    WUWT had this “NOAA goes full alarmist with new publication, seeing AGW in extreme weather events” at http://wattsupwiththat.com/2013/09/05/noaa-goes-full-alarmist-with-new-publication-seeing-agw-in-extreme-weather-events/ .

    In my view, it is the responsibility of professional scientists and their citizen counterparts to call out the bad actors in their own fields. There has been some of this beginning over the last few years, and we can only hope for more. A recent example is Dr. Judith Curry quoting her “Concern over how the community of climate scientists allowed intolerant activists who make false claims to certainty to become the public face of the field – Roger Pielke Jr” (italics indicate words written by Dr. Pielke) at http://judithcurry.com/2013/09/17/consensus-denialism/

  34. Gary Pearse says:
    September 19, 2013 at 6:30 am

    “I think an obvious omission to your calculations is the effect of the stone, steel, concrete, glass glacier that has been growing, particularly during the 20th Century over Manhattan.

    The buildings do not rest on the ground, but on piles which are driven down to the very bedrock.If you’ve ever held your ears while passing a construction site because of an incredibly loud banging sound, as in this video, that’s what you’ve been hearing.

    The Ghost Of Big Jim Cooley says:
    September 19, 2013 at 8:49 am

    “The term ‘Period’ is redundant. It adds nothing to the sentences and is therefore superfluous. Sorry, but the English do find it quite annoying.”

    “Oh, why can’t the English learn to speak?” – Henry Higgins ;-)

    It adds emphasis.

  35. Reply to u.k.(us) (September 19, 2013 at 11:13 am): “Yet, we are trying to find millimeters of sea level rise. I don’t think GPS is accurate enough yet.”

    Please remember that I only attempt to use “reasonably accurate and readily agreed upon approximations.”

    Observation of glacial isostatic adjustment in ‘‘stable’’ North America with GPS, Sella et al. 2007 ( http://www.ngs.noaa.gov/CORS/Articles/2006GL027081.pdf ), generally accepted on this point, gives the following:

    The density of space geodetic measurements in Eastern North America has recently increased dramatically. Using publicly available continuously recording GPS (CGPS) sites, Sella et al. [2002, 2004] identified uplift in areas where significant present-day GIA is expected. Here
    we use a much larger GPS data set to measure the full three-dimensional surface velocity field. For this purpose, we augment CGPS data with a large set of episodic GPS (EGPS) data collected at sites in Canada that have been occupied for a few days every three to four years. The
    EGPS data dramatically improve spatial coverage, especially in the critical region of large uplift rates around Hudson Bay near the centre of the former Laurentide ice sheet

    These findings are supported by Spatial variability of late Holocene and 20th century sea-level rise along the Atlantic coast of the United States Englehart et al. 2009. http://geology.gsapubs.org/content/37/12/1115.abstract (abstract only)

    I have queried and expert in this area, Dr. Stephen M. Lichten, Deputy Manager: JPL Communications, Tracking & Radar Division, on this point and will let you know what he says.

  36. Kip Hansen says:

    September 19, 2013 at 12:12 pm
    ==========
    It is a whole thing !!
    The land surveyors would love millimeter accuracy on the fly, we’re getting close but not quite there yet.
    Especially in the vertical.

  37. I haven’t read through all the comments but this kind of thing puzzles me. The quote is a common example: “sea levels continue to rise due to global warming. The picture here is very clear. And that means that every single hurricane that hits land will push seawater farther inland when it does so. Or as one scientist told me in the wake of Sandy, “There is 100 percent certainty that sea level rise made this worse. Period.”

    I don’t see how this claim can be made. Natural tidal ranges spread from low to max high water. Storms strike at unpredictable moments in that range. The only way that flooding can be outside of the range of historical possibility is if SLR has increased the range at the high end and the storm strikes at a time when the tide is at that level.

    For example, even if sea level locally has risen a foot, if the storm strikes at low tide and that level is within historical parameters then the flooding is within expected bounds. Yes, you could argue that the level at that moment was higher than it was at some previous time, but how far can you go with that argument?

    Did Sandy have a higher surge due to AGW? Maybe. Was it outside historical possibilities? We’d need to know the predicted high tide for that day (given the storm struck at high tide) and compare that to the historical range of tide heights.

  38. Continuing Reply to u.k.(us):

    Dr. Lichten has referred me to the following to answer your uncertainties on GIA and GPS accuracy:

    International GPS Service (http://igscb.jpl.nasa.gov/igscb/resource/pubs/IGS_sp.pdf) gives a chart of Geocentric Coordinates of IGS Tracking Stations (>250 sites) at which indicates a weekly accuracy of 3 mm, which means that over time, one can fit several years of data to less than a millimeter/year rate.

    The 2008 presentation by Lichten ( http://www.oosa.unvienna.org/pdf/icg/2008/icg3/22.pdf ) on chart #23, indicates results of 0.36 and .040 mm/yr.

    This page http://xenon.colorado.edu/spotlight/index.php?product=spotlight&station=CHUR details measurements made at Churchill, Canada, on the Hudson Bay in millimeter accuracy (see graphs at the lower right).

    Remember, it takes a long time (months at least) and specialized GPS equipment and analysis to get results to this accuracy.

    All this said, it isn’t my data, so I can not defend it. I simply use the generally widely accepted data for GIA vertical movement.

  39. Reply to Graeme M (September 19, 2013 at 1:50 pm): “I don’t see how this claim can be made.”

    Their claim refers to the True part –> I said “the TRUE and obvious fact that any positive change in local average relative sea level will make any storm surge ‘worse’ – by the simple effect of the relative water level being higher by whatever amount”. If the water level starts out 6 inches higher, then the resultant water level from the surge will probably be 6 inches higher, thus more flooding. If the relative sea level had stayed at the 1960 level, there would have been less damage — those areas flooded by those extra “4 to 6 inches” would not have been flooded.

    See my reply about tide here http://wattsupwiththat.com/2013/09/19/from-the-scientific-urban-legend-department-agw-sea-level-rise-made-sandy-more-destructive/#comment-1421351 and follow the link I give on that issue.

  40. Kip Hansen says:

    September 19, 2013 at 1:51 pm

    “Remember, it takes a long time (months at least) and specialized GPS equipment and analysis to get results to this accuracy.

    All this said, it isn’t my data, so I can not defend it. I simply use the generally widely accepted data for GIA vertical movement.”
    =====================
    I never expected you to defend it.
    Just wanted to delve a bit deeper into the science behind it.
    Mission accomplished.
    Thanks, the effort hasn’t gone unnoticed.

  41. The Ghost Of Big Jim Cooley says:
    September 19, 2013 at 8:49 am

    As has been mentioned, “Period1″ has an accepted definition, no matter how much it causes chapping of the Brits’ hindquarters. Of course the Brits use the term “Full stop!”, a synonym for ― wait for it ― “Period!”, which tends to have an abrasive effect on my own Texian nether regions.

    Arent these OT excursions fun?

    cheers,

    gary

  42. So there’s a 10 inch rise in sea level which made flooding worse from Sandy? Hmm. To my understanding the Earth was considered to be a perfect sphere till the advent of satellites in the 1950s showed that it wasn’t a perfect sphere. Apparently centrifugal force makes it bulge slightly at the Equator compared to the poles. A mere few thousand years to discover this and now, courtesy of bucket loads of taxpayer funding, we’ve learned everything there is to know.

    According to Geography about.com (relying on NASA) the Earth’s diameter at the poles is a precise 7,901 miles and its diameter at the Equator is 7,926.41 miles. So the Earth clearly bulges. So far so good. Except this same geography site also shows the Earth is 7,899.8 miles in diameter at the poles and 7,926.28 miles in diameter at the Equator. I know, I know, I know I’m nitpicking. After all, that’s only a 0.0015% difference the same site has displayed at the poles. Except that miniscule percentage difference equates to 1.2 miles which equals 6,336 feet which equals 76,032 inches. Last time I checked that’s quite a bit more than 10 inches.

    Ah, but that’s unfair. The figures quoted for the Equator, on the other hand, are closer; only 0.13 mile difference in diameter. So, now we’re only talking about 8,236.8 inches. Still, one whole heckuvalot more than 10 inches.

    So, we can’t quite seem to get the exact diameter quite right, but gosh, we can still detect a sea level rise of 10″. And, just how many inches are there in the lower end equatorial diameter? I’m not good at arithmetic but I multiply it to 502,209,100.8 inches.

    And we can tease an accurate 10 inch change out of that? And, besides this amazing accuracy, we can determine, with the same precision, that human beings are responsible for that very same 10 inches. Never mind that the Earth’s surface grows each and every year from dust deposited by those meteors we see burning up in our atmosphere. Never mind that this same dust must drift to the oceans’ floors thus raising their levels. And we don’t know the ratios. Also, never mind the silt that the rivers, great and small, carry off to the oceans, also raising the height of the sea bed, and for proof of that check out the badlands. And, never mind the impacts of plate tectonics, glacial rebound, erosion, underwater volcanic activity, and so on, and so on. And, also never mind that we’re measuring a fluid surface driven by currents, known and unknown; driven by the moon’s gravity; and whipped into waves. And it’s a fluid surface that will respond to any heat buildup by increased evaporation, thus negating somewhat its very own expected heat increase, and additionally transporting a portion of its volume to the air above.

    No, we’ve factored in all of this, did our calculations, and detected a difference that’s vanishingly small. I don’t believe you.

  43. Nice article.
    Battery Point data pretty clearly demonstrates that the ‘average tide guage data’ sea rise of about 1.7 mm/year (for several hundred years) is correct and ongoing, and the satellite 3 mm/year is simply wrong.

    And, at the end of the day, we really are only worried about relative sea rise, NOT a theoretical measure of ocean volume (which is what we get with satellites plus 0.3 mm/year GI Adjustment).

  44. Pippen Kool says: September 19, 2013 at 6:31 am

    Regardless of subsistence and other geological changes, flooding has to be worse with additional sea level rise. Logic.

    But perhaps missing the point of the claim: That the flooding experienced is primarily due to AGW driven sea rise.

    And therefore missing the point of the discussion: If there has been several hundred years of slow but steady sea rise with no recent acceleration, perhaps it is not due to anthropogenic influences, so we had better adapt and learn to live with it, and more so where the land is subsiding.

  45. Two links with analysis showing very low changes in sea level.
    First is a NOAA assessment using best data available from 2005.

    http://hockeyschtick.blogspot.com/2012/12/noaa-2012-report-finds-sea-levels.html

    Second is an analysis of the Tasmanian tidal benchmark made in 1841 with documentation.

    http://bruderheim-rea.ca/warming10.htm

    Also, I’ve seen a Will Soon video where he comments to the effect that satellite altimetry raw data shows zero sea level rise, but is “corrected” to match tidal gages.

  46. Thanks for your reply Kip and I will read the link in detail when I get a moment. But my point was something a little different. I was just observing that regardless of some absolute effect of SLR, a storm surge can’t have an effect outside of an expected range if the local tide height was within the historical range. Was the predicted high tide at the time Sandy struck within historic norms – say last 50 years? If so then the flooding could not be worse than planning would indicate.

    That of course ignores questions of intensity but I think again Sandy was within norms there.

  47. From gary turner on September 19, 2013 at 2:41 pm (with slight correction):

    As has been mentioned, “Period[!]″ has an accepted definition, no matter how much it causes chapping of the Brits’ hindquarters. Of course the Brits use the term “Full stop!”, a synonym for ― wait for it ― “Period!”, which tends to have an abrasive effect on my own Texian nether regions.

    Didn’t this all come from telegraphs and telegrams?

    I AM LEAVING YOU PATCHY COMMA FOUND MODEL I CAN TRUST PERIOD

    URGENT STOP WEE BAIRN FELL IN WELL STOP SEND REPLACEMENT WATER TO WHISKEY MAKER NOW STOP FULL STOP

    Things would be so much easier if Morse had known enough computer science to make EOL and EOF codes.

  48. CNC says:
    September 19, 2013 at 6:57 am

    Long Beach Island New Jersey, where I use to summer as a boy, was hit badly by Sandy and lot of people blame AGW. But they seem to forget the 1962 Ash Wednesday Storm which was much more destructive all up the Eastern seaboard….

    I have never seen this storm mentioned in any article talking about Sandy including on this web page. It should be.

    http://en.wikipedia.org/wiki/Ash_Wednesday_Storm_of_1962

    I covered the 1962 storm in http://wattsupwiththat.com/2012/03/06/50-years-ago-the-great-atlantic-storm-of-1962/ I think it’s much better than the Wikipedia article, especially if you want an LBI focus. Heck, I even included on of my Dad’s photos of Old Barney.

    From Googling |sandy 1962 site:wattsupwiththat.com| I see several articles that, including comments, mention both. Three from me, one from you, one from someone else:

    http://wattsupwiththat.com/2012/11/02/next-time-somebody-tries-to-tell-you-hurricane-sandy-was-an-unprecedented-east-coast-hurricane-show-them-this/

    http://wattsupwiththat.com/2012/11/18/discovery-channel-fail-sandy-was-not-a-megastorm/

    http://wattsupwiththat.com/2012/10/26/noaa-and-fema-gearing-up-for-sandy/

    http://wattsupwiththat.com/2012/10/28/stunning-super-high-res-image-of-hurricane-sandy-plus-forecast-of-a-large-storm-surge/

    http://wattsupwiththat.com/2013/08/29/the-great-labor-day-hurricane-of-1935/

    Aside – I’m trying to write an article about the Hurricane of 1938. Well, other weather events that should be mentioned will be the focus. Too many distractions these days, so I may not make it in time.

  49. Ric Werme says:
    September 19, 2013 at 5:40 pm

    “I covered the 1962 storm in….”

    Sorry I missed those comments. Good stuff. Looking forward the the article on the Hurricane of 1938.

  50. Please use, or add, synonyms for the word “significant” whenever it is employed in the scientific sense in articles like this. In lay speech, it means large, or important not merely statistically different from zero.

  51. Izen says:

    “But the reality is that the local sea level rise is always a combination of the global rise and the much smaller local effects.”

    Actually the local effects are probably more often than not larger than the global rise.

  52. Kip
    I don’t know if you’re still reading comments on this article, but a couple of more, then I’ll leave you in peace:
    ———————-
    Remember, it takes a long time (months at least) and specialized GPS equipment and analysis to get results to this accuracy
    That’s my impression, but I haven’t researched the issue in detail. A factoid to file away if you don’t already know it is that there is a geometric issue with GPS or any other “astronomical” position measurement in that most observations will be at low locally measured elevation because much more of the visible hemisphere is at low elevation angle than at high. Low elevation angle means lots more (local) horizontal information than (local) vertical information. i.e. for a given set of observations — especially a large set — the horizontal (lat-lon) estimate will probably be considerably more accurate than the vertical (altitude) component.
    ———————–
    It’s probably impossible to determine with current information to precisely estimate sea level rise. Much less partition it into natural and human causes. If it were easy, tidal gauge and satellite estimates would agree closely. But one thing everyone should be able to agree on is that humans have been building far too much vulnerable infrastructure at/near “sea level”. Shorelines are a great place for parks, parking lots, airport runways (If you don’t mind their being out of service from time to time). They are a poor place for permanent structures unless the “buildings” are either hardened against occasional flooding or can be moved out of harms way when necessary.

  53. Reply to Brian H (September 20, 2013 at 12:57 am): You are right, of course, in prose about science, “significant” is a loaded word, with too many contradictory meanings. I try to write in plain everyday English (and wish everyone would do so). In my “Bottom Line” sentence “At the Battery, Manhattan, NYC, there has been, so far, no significant sea level rise attributable to AGW” I meant this:

    sig·nif·i·cant (adjective)
    1. sufficiently great or important to be worthy of attention; noteworthy.

  54. Reply to Don K (September 20, 2013 at 2:15 am): If the time stamp is valid for your time zone, you’re staying up way too late on the ‘Net. You are right about GPS vertical accuracy being less and harder, right about measuring ‘global’ sea level (at all, in my opinion), and right again about building cities on mud flats, barrier islands and sand bars. You’re batting 1000.

  55. Pippen Kool says: @ September 19, 2013 at 6:31 am

    Regardless of subsistence and other geological changes, flooding has to be worse with additional sea level rise….
    >>>>>>>>>>>>>>>>>
    To put it into pictures what is being said: graph Sea Level Rise

  56. Significance is in the eye of the beholder. Meaning that if you drill down to a tiny piece of graph and use a finer scale, then include only that tiny piece of data string in your overall linear trend analysis, all kinds of potentially spurious significant and scary things can be said about your findings when examining a piece of your tiny piece of graph on a scale that allows you to see a gnat wriggle his ass.

    For example, if I were to measure the size of all bird beaks, I could say that the range is very wide indeed and that significance does not appear to come into play. The data is that noisy. However within the species of sparrows, I could say that there are significant differences and I would try to determine why. If I were to measure the size of beaks within a single subspecies of sparrows, I could say that there are significant differences and I would try to determine why. If I go too narrow (say a subspecies within a regional range) significance begins to disappear again, UNLESS I use a finer scale. It is here where spurious significance is most likely to raise its head. Many species of birds have been divided up into subspecies to the point of ridiculousness, which is now slowly being reversed back to reasonableness.

    Most researchers understandably try to find what I call the “sweet spot”. Which is that point within the broad range of data that I could possibly find significance but not too fine a point where true significance begins to disappear again.

    I think the problem with our current field of climate researchers is that they have drilled down past the true sweet spot and have changed the scale to too fine a division. So now they are finding all kinds of potentially spurious significant and scary things that can be said about their findings when they are examining a piece of their tiny piece of graph that allows them to see a climate gnat wriggle its ass.

  57. Reply to Gail Combs (September 20, 2013 at 8:05 am): The graph you link to represents Post-Glacial Sea Level Rise, and covers a time span of 24,000 years. Please note that for practical purposes, the part of this graph that concerns mankind
    is the last, nearly flat, 7,000 years. The part of this graph that applies to the subject of this essay is represented by a single dot, containing zero discernible information. The graph that does apply to this essay is at the NOAA web site here –>http://tidesandcurrents.noaa.gov/sltrends/sltrends_station.shtml?stnid=8518750 and the graph from CSIRO in the body of the essay above.

  58. Kip, thanks for your replies to my earlier comments, but I think you may have missed the point I was making. Or else my point is well… pointless :)

    I was observing something about the claim that AGW driven SLR will make EVERY storm surge worse.

    While in an absolute sense that might be true, ie a storm surge on top of a water level that is one foot higher will therefore be one foot higher than it would otherwise have been, that’s a somewhat meaningless statement.

    The point is that (disregarding factors of storm intensity and duration) you cannot predict beforehand the time of a storm’s arrival. So the severity of any storm surge is dependent on the tide height at the time of that storm’s arrival, as you note in your article.

    For any given location, the local range of tidal variation gives you the likely range of storm surge effect. That is, if your range is 1 foot to 4 feet, then a surge of 3 feet will give you a storm tide range of 4 to 7 feet.

    What I am saying is that in a planning scenario, a storm surge of any height at all that arrives on top of a tide that falls within the local tidal range cannot produce a storm tide outside of historic likelihood.

    This means that while you might be able to suggest that a storm surge will cause a storm tide of greater proportion in an area where local SLR has changed the MSL, that’s a meaningless fact UNLESS it occurred at a time when the local tide was outside of the historic range. For the simple reason that it is not until the local tide is higher than the historic range that you will have a storm tide outside the historic range.

    In the case of Sandy, we’d need to know if the predicted high tide for the time that Sandy struck is outside the expected range. Of course it was if we use say 100-150 years ago as our period, but in fact we know that the current National Tidal Datum Epoch was set in the period 1983-2001. That’s a bit recent, so we could go to the next earlier one, 1960-1978. That’s a good period as it’s closer to the time after which AGW really is supposed to have kicked in.

    So, was the predicted high tide for Sandy’s time of arrival higher than the highest high tide measured in the period 1960-1978? My rough figures from the data tell me that the high tide was predicted to be 1444mm. Adjusted, that is 2446mm above the local Benchmark.

    The Mean Higher High Water for the period 1960-78 was 2496mm, so we can see that the high tide was about 50 mm below the max likely range for the period in question.

    Now, thats a rough calc and I am making no guarantees of accuracy and maybe I’ve missed something, buit it APPEARS as though Sandy’s storm tide was not outside the range that could be expected to occur. My point is simply a conceptual one.

    What do you think?

  59. Reply to Graeme M (September 20, 2013 at 2:12 pm): “While in an absolute sense that might be true, ie a storm surge on top of a water level that is one foot higher will therefore be one foot higher than it would otherwise have been, that’s a somewhat meaningless statement.” I do see your point. You hit it right on the nail head, Graeme. I can see that you had trouble seeing how the authors of “The Claim” could be so simplistic. Astonishing, isn’t it?

    My comment on that was “…the TRUE and obvious fact that any positive change in local average relative sea level will make any storm surge ‘worse’ – by the simple effect of the relative water level being higher by whatever amount” and, of course, you are right, any relative sea level rise–from whatever cause–has the same effect. The meaninglessness of it is that we (Mankind) are not masters of the sea level, the sea does not do our bidding.

  60. Kip, just an aside to this. I have little free time to read through all the comments and I’d need to spend a few minutes thinking through your post in more detail, but I wondered if you’d made allowance for the adjustments to datum points for The Battery?

    I have to admit to not understanding this stuff so my comments may be well wide of the mark.

    Mean tide heights and hence MSL are calculated from the reference point of Mean Lower Low Water which is set to zero. However I think that relative to the local benchmark. Tidal datum are set according to a 19 year cycle called the National Tidal Datum Epoch. The current value for the Mean Lower Low Water is 1.002 metres whereas for the previous Epoch (1960-78) it was .936 metres.

    In effect, I think what I am saying is that although the tidal datum values (eg MSL) are directly comparable, their basis is adjusted regularly to allow for things like land movement.

    So there is an adjustment of some 66mm in there which may affect your calculations? And if you are calculating since 1960, you probably need the adjustment for the Epoch prior to the 1960-78 one as well. Assuming it would be similar, that could be as much as 100mm.

    Could be quite wrong cos I am no expert, just wondered if you’d allowed for that? Or if it’s even relevant.

  61. Reply to Graeme M (September 20, 2013 at 4:45 pm): The graph at http://tidesandcurrents.noaa.gov/sltrends/sltrends_station.shtml?stnid=8518750 (which is in the essay above) is the local sea level relative to a solidly mounted brass marker (benchmark) on bed rock. It is NOT adjusted for anything, as far as I know. There is an explanation at http://tidesandcurrents.noaa.gov/sltrends/ under the heading ‘Products’. There is further clarification/confusion at http://tidesandcurrents.noaa.gov/datum_options.html . For my simple essay, I use only the very simple statement from the New York State Sea Level Rise Task Force “4 to six inches” of rise at the Battery, 1960-2010. I am sure that there is a lot to know about how NOAA takes a dynamic system like “sea level at the Battery” and reduces it to a series of numbers. Hope this addresses your concern.

  62. Kip check the level of the MLLW datum for both the current and previous tidal epochs.

    Here is the current epoch in meters:
    MLLW 1.002 Mean Lower-Low Water

    Here is the previous epoch:
    MLLW 0.936 Mean Lower-Low Water

    Here’s tidal datums for the present epoch. Note that MLLW is shown as zero. I assume that at all times the MLLW value is zero, but its offset varies depending on epoch.

    Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:

    HIGHEST OBSERVED WATER LEVEL (10/30/2012) = 4.280
    MEAN HIGHER HIGH WATER MHHW = 1.541
    MEAN HIGH WATER MHW = 1.443
    North American Vertical Datum NAVD88 = 0.846
    MEAN SEA LEVEL MSL = 0.783
    MEAN TIDE LEVEL MTL = 0.753
    MEAN LOW WATER MLW = 0.063
    MEAN LOWER LOW WATER MLLW = 0.000

  63. Imagine if the world spent a quadrillion dollars to make itself carbon-neutral and then the post-LIA warming and SLR trends continued unabated! Then they spent a few million on sea walls around Manhattan and got on with life.

  64. Reply to Graeme M (September 20, 2013 at 8:31 pm): Looks like you are well on your way to having enough background material to write an essay on “How Sea Level is Determined”. I look forward to reading it here.

  65. THANK YOU!

    Thanks to all the WUWT readers who read this essay, and especially to those who commented, asked questions, and clarified points for other readers.

    My personal thanks to Anthony Watts for providing this important forum for Citizen Science. He is an inspiration to me, as he is to many others. And thank to all those who, in big and little ways, support Anthony and the WUWT blog.

    I will be working on other projects this week and probably not responding daily to comments on this essay.

    Blue skies and following seas,
    Kip Hansen

    PS: Those who simply must communicate with me on this or any other issue may email me using kip and the domain i4.net.

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