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Sea Level Rise per Jevrejeva

July 25, 2017
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By Paul Homewood

 

 

I’ve looked at UK sea level rise, but what about global?

As well as the much adjusted satellite datasets, we have a Global Mean Sea Level Reconstruction by Jevrejeva et al, published in 2014 and with data up to mid 2010. This is how the PSMSL describe it:

This page provides a short description and file with data of global sea level reconstruction for the period 1807-2010 by Jevrejeva, S., J. C. Moore, A. Grinsted, A. P. Matthews and G. Spada. All questions about the data themselves should be addressed to Dr. Svetlana Jevrejeva.

Authors have used 1277 tide gauge records of relative sea level (RSL) monthly mean time series from the Permanent Service for Mean Sea Level (PSMSL) database [Holgate et al, 2013]. Detailed descriptions of the RSL time series are available from the data page at the PSMSL. No inverted barometer correction was applied. RSL data sets were corrected for local datum changes and glacial isostatic adjustment (GIA) of the solid Earth [Peltier, 2004].

More information about data and methods for the calculations of global sea level and errors can be found in:
Jevrejeva, S., J.C. Moore, A. Grinsted, A.P. Matthews, G. Spada. 2014. Trends and acceleration in global and regional sea levels since 1807, Global and Planetary Change, vol 113, doi:10.1016/j.gloplacha.2013.12.004

The data file can be downloaded by clicking here.

http://www.psmsl.org/products/reconstructions/jevrejevaetal2014.php

 

 

My thanks to David Middleton who posted this graph at WUWT and saved me a job!

j14_01b

https://wattsupwiththat.com/2017/07/20/sea-level/

As you can see, the rate of rise was very similar between roughly 1930 to 1960, as it has been since 1990. We see the same pattern at UK sites.

David’s graph mirrors that of the original paper. As with most sources of sea level data, the scale is set to make the rise appear to be astronomic.

Given that the IPCC is forecasting a rise of a meter and more by 2100, a more appropriate scale would look like this:

image

 

 

But on a more serious note, as David’s graph shows, there is a very sharp upward spike in 2009 & 2010. The actual Jevrejeva data shows a rise of 44mm in the last 12 months, ending in June 2010. Whilst there have been similar spikes, followed by equally sharp drops in earlier periods, it is hard to believe that this figure is not totally spurious.

Prior to this spike, sea levels had risen by 21mm in the previous 10 years. In other words, only slightly above the 20thC average, and well below the 3mm a year claimed by satellite data.

Moreover the Jevrejeva spike does not appear in the satellite datasets.

http://sealevel.colorado.edu/

 

Let’s now focus on the rise in sea levels, measured over 120 months. (Note, the Y-scale is mm per year).

image

 

There is clearly a lot of noise in the early 19thC, and the error bars are naturally huge. There is though a clear around the middle of the century.

We can get a better picture of what has happened since 1900 by excluding the earlier data:

image

 

Even with the 2010 spike, the 120-month rise is only slightly higher than the 1939 peak. If we ignore the 2010 spike as spurious, we are left with a figure of 2.16mm/year, which is low by the standards of much of the 20thC.

It is worth pointing out by the way that the peak prior to 2010 was 5.13mm in 2003. This spike was largely due to the rebound after Pinatubo, as sea levels fell sharply in 1991, and did not start recovering until 1994.

Between 1989 and 2009, for instance, sea levels rose by 44mm, ie 2.2mm per year.

There is no evidence from any of this that sea level rise will quickly start to accelerate, as the “experts” keep telling us.

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14 Comments
  1. Joe Public permalink
    July 25, 2017 9:52 am

    Am I alone in subconsciously associating the acronym PSMSL with “PisSMySelfLaughing?

  2. quaesoveritas permalink
    July 25, 2017 9:58 am

    Why is it that we don’t hear much about sea levels when they are falling i.e. prior to the recent spike? This probably leaves the majority of people thinking they only ever go up . If sea levels decline in coming years, you can bet that C.C. alarmists will go on saying that they are still rising.
    The same thing applies to other climate related topics, e.g. ice extent in the Arctic. Most people probably think it is continually declining and there is almost none left.

    • Simon from Ashby permalink
      July 25, 2017 12:24 pm

      I think the expression is – “the trend is still upwards”.

  3. July 25, 2017 10:15 am

    Chock full of useful info
    Very helpful indeed.
    Thank you.

  4. Jack Broughton permalink
    July 25, 2017 10:17 am

    I am curious as to why anyone worries about mean se levels, apart from a fear campaign of course. Surely it is the high level that would cause flooding and damage? Is that reported or assumed to be the same as the mean rise?

  5. Keitho permalink
    July 25, 2017 10:31 am

    Very informative article. Thanks Paul, your diligence in these matters is greatly appreciated by a great number of people.

    I live next to the Atlantic ocean and it hasn’t moved up here in the 60 years I have been looking at it.

  6. July 25, 2017 10:47 am

    But the data must always be made to look/sound bad – by order of the climatology management.

  7. July 25, 2017 11:54 am

    Several months ago I discovered an old archaeology series on YouTube, “Time Team.” It is fascinating to see the reconstruction of coastal areas in the neolithic to present in various of the segments. It is not just the draining of marshes either. It shows the rise in sea levels with interglacial warming, the Medieval Warming and the fall of the levels with the Little Ice Age, etc. It is stunning to see where your old “coastal” ports were at previous times and where there are “drowned” forests.

  8. Broadlands permalink
    July 25, 2017 12:58 pm

    Glorious (Glorioso) Islands, Madagascar

    JAMES HORSBURGH, FRS, AS:

    “GLORIOUS ISLANDS, two in number, are low, small, situated on a reef, about 38 or 40 leagues to the W. N. W. of Cape Ambre. Capt. Moresby, in the Menai sloop of war, touched at these islands in 1821, and made the eastern one in lat. 11° 32½′ S. lon. 47° 39′ E. and the western one in lat. 11° 34¾′ S. lon. 47° 30′ E. by observations of sun and moon, nearly agreeing with chronometer. They are covered with brush wood and trees 20 or 25 feet high, and are about 15 feet above the sea level, connected by a coral bank nearly 3 miles in breadth in some places, which space is filled with small isles, sand banks and lagoons, through which no passage appears…”

    Wikipedia… Glorioso Islands…today

    “The climate is tropical and the terrain is low and flat, varying from sea level to 12 metres (39 ft). Île de Lys in particular is a nesting ground for migratory seabirds and turtles lay eggs on the beaches.”

    About 15 feet in 1821 and about 20 feet, higher now after 190 years? Certainly not submerged.

  9. Rowland H permalink
    July 25, 2017 2:47 pm

    If sea levels are rising at whatever rate, where is all the extra water coming from? Is there displacement being caused by submarine volcanoes for instance?

    • quaesoveritas permalink
      July 25, 2017 5:11 pm

      Melting glaciers (not sea ice) and increasing water temperatures.
      (according to the alarmists).

      • MrGrimNasty permalink
        July 25, 2017 6:40 pm

        And a bit for ground water extraction.

    • Drew permalink
      July 25, 2017 8:03 pm

      How much displacement of seawater is due to sediments carried downstream by rivers? Does anyone know if this a significant factor?

  10. tom0mason permalink
    July 25, 2017 8:26 pm

    Of interest here may be NASA’s supposed ‘facts’, sea-level rises have apparently leveled off and fallen.

    See https://climate.nasa.gov/vital-signs/sea-level/

    Warming since the end of the last LIA and sea-levels necessarily rise, however now they’ve stalled signaling what I wonder?

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