Sea Level Rise per Jevrejeva

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!

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:

 

 

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).

 

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:

 

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.