More Sea Level Exaggerations about the IPCC

Written by Nils-Axel Mörner Paleogeophysics & Geodynamics, Sweden,

Aslak Grinsted has just posted a document, which is said to be “a nice figure which compares the 21st Century sea level projections”. I would say it is another one of all those exaggerations that the IPCC supporters seem to feel that have to produce to save the story.

Firstly, Grinsted claims the National Oceanic and Atmospheric Administration (NOAA) satellite altimetry data gives the true reading of what has been going on in the last 20 years with global sea level. Therefore he – without any hesitation– proclaims that this value constitutes “an absolute lower limit” of the sea level by 2100.

This is certainly NOT true. The satellite altimetry data have been severely modified by quite subjective so-called “corrections”. Therefore, it cannot be used as a measure of actual sea level changes (e.g. 1, 2).

Secondly, the so-called “ice sheet experts” are said to give values equivalent to a sea level rise from 28 to 145 cm. This is a remarkable exaggeration, which violates physical laws and knowledge accumulated over a very long period of time (e.g. 1).

The only scientifically defendable value of the present rate of sea level changes is somewhere in the sector between ±0.0 to 1,7 mm/year sea level rise (see 1, 2). A value that is far below all the model predictions, as illustrated in the below figure.

IPCC projected sea level change

Figure 1. Grinsted’s original diagram corrected to show actually observed sea level variations (red box) and its extension of the various model out-puts (yellow line).

Consequently, Grinsted presents a strongly exaggerated and incorrect picture.


1 Mörner, N.-A., 2013. Sea level changes: past records and future expectations, Energy &

Environment, 24 (3-4), 509-536.

2 Mörner, N.-A., 2013. Sea Level Changes: a short comment. The Global Climate Status

Report (GCSR), September 2013, p. 5-9.


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