Critique of “Global sea level linked to global temperature,” by Vermeer and Rahmstorf

I was highly critical of Stefan Rahmstorf’s 2007 attempt to scare the world about sea level rise. He claimed that any temperature rise would result in an increase in the sea level rise rate that would take a millenium to dampen out. I pointed out at the time that this claim was contradicted by the very data that he used.

Now, Martin Vermeer and Rahmstorf (referred to as “VR2009” for the rest of this article) have given it another try in their 2009 PNAS paper, “Global sea level linked to global temperature”  (referred to as “VR2009” in this series of posts).  They have added another term, dT/dt which they say “corresponds to a sea-level response that can be regarded as ‘instantaneous.'”

This series of posts considers some of the bizarre consequences that would result if VR2009 were correct.  These unrealistic results necessarily lead to the rejection of VR2009

Part 1, The basic problem.

Part 2, A little more detail on the math.

Part 3, A few examples that show some bizarre consequences that would result if Vermeer’s and Rahmstorf’s model were correct.

Part 4, Improbable parallel universes.

Part 5, Variation of gamma.  Fast increasing temperatures cause sea level rise rate to drop, while slowly increasing temperatures cause sea level rise rates to increase.

A look at Church and White sea level data.  This is the sea level data that is the foundation of VR2009.

Response to RealClimate comments.  A few poorly considered comments concerning this series about VR2009 showed up at RealClimate.  This is my response.

Chao’s artificial reservoir “correction” to sea level.  This “correction” to Church and White’s sea level data leads to a (supposed) larger sea level rise during the 20th century.  But this “correction” has some critical flaws.

Part 6, Vermeer’s and Rahmstorf’s model is applied to satellite sea level data and fails the test.

Part 6.5,  the gory mathematical details from part 6.

Part 7  What does Vermeer’s and Rahmstorf’s model imply for a constant sea level rise rate of 3 mm/year?

Part 8, My reproduction of Vermeer’s and Rahmstor’s results

25% of sea level rise rate is due to groundwater depletion, not global warming.  Yet Vermeer and Rahmstorf did not correct their model for this effect.

Part 9,  What happens when Vermeer’s and Rahmstof’s model is applied to the updated Church and White sea level data with a Wada groundwater depletion correction?  The effect is huge

Part 10, Vermeer and Rahmstorf used out-dated sea level data from Church and White, and did not correct for groundwater depletion.  When Church’s and White’s updated sea level data is used and a groundwater depletion correction is incorporated, then their model yields 21st century sea level rises that are only half of what Vermeer and Rahmstorf reported.

Part 11.  Here is Vermeer’s and Rahmstorf’s Matlab source code.

Part 12. Vermeer and Rahmstorf claimed to apply a sea level correction based on Chao’s artificial reservoir data.  Instead, they use an inverse tangent function that hardly resembles Chao’s data.

Part 13.  Vermeer and Rahmstorf applied their model to IPCC temperature scenarios for the 21st century.  But here are some hypothetical 21st century temperature scenarios the bring out the bizarre effects of VR2009.



  1. […] Remember the “correction” to the sea level from Chao that made the sea level rise rate for the second half of the 20th century appear to be higher  (surprise, surprise) than the commonly referred to Church and White sea level data (Church, J. A., and N. J. White , “A 20th century acceleration in global sea-level rise”, Geophys. Res. Lett., 33, 2006)?  I wrote about it back in May.  Martin Vermeer and Stefan Rahmstorf were all too happy to include this “correction” in their model relating sea level to temperature, of which I have written about extensively. […]

  2. […] Moriarty discovers the paper is riddled with gross errors and false assumptions, read overview here. […]

  3. […] paper, one in the Proceedings of the National Academy of Sciences says their math was wrong; the other by a Senior Scientist at the US Department of Energy’s National Renewable Energy Laboratory lists […]

  4. […] Mosher has graciously pointed me to a stunning disassembly of V&R2009, at the blog Climate Sanity. Makes my effort above look simplistic by comparison. He shows, among other things, that the […]

  5. […] Generation 2, from Vermeer and Rahmstorf’s 2009 ”Global sea level linked to global temperature“ […]

  6. […] I noted in the previous post, the KMVR2011 model is the progeny Vermeer and Rahmstorf’s 2009 PNAS model and Rahmstorf’s 2007 Science […]

  7. […] TOPICS RSS Main Page About ClimateSanity by Tom Moriarty PoliticalPen Conversion factors for ice and water mass and volume Criticisms or Al Gore's "An Inconvenient Truth" Critique of "A Semi-Empirical Approach to Projecting Future Sea Level Rise" by Rahmstorf Critique of "Global sea level linked to global temperature,” by Vermeer and Rahmstorf […]

  8. […] of the National Academy of Science, December 22, 2009 vol. 106 no. 51 21527-21532 ).  It has been incontrovertibly demolished, but the believer’s just can’t let it go.  They must suffer theory-induced […]

  9. […] than Herr Rahmstorf, who has spent the better part of his career making the point.  He has even provided a in his 2009 paper to translate the global temperature to the sea level rise […]

  10. […] is a little hint for my obvious betters at the NRC: When you rely on the models of Stefan Rahmstorf to make your sea level rise predictions, one of two things will have happened by 2030.  If you are […]

  11. […] files have a consistent format which can be read by my code that calculates fit parameters for the Rahmstorf model relating sea level to temperature.  However, not all of the time series are long enough to be useful in that […]

  12. […] for the 21st century into equation 1 and calculate the resulting sea levels.  I have provided a long list of criticisms of their logic.  One of the most devastating observations is that their own source of […]

  13. […] Vermeer & Rahmstorf, 2009 (Open access) believe that the computer models underestimate future sea level changes. So, they didn’t actually simulate sea level changes, but instead estimated how much sea level rise they would expect from man-made global warming, and then used computer model predictions of temperature changes, to predict that sea levels will have risen by 0.8-2 metres by 2100. (The blogger Tom Moriarty has heavily criticised the Vermeer & Rahmstorf, 2009 study on his Climate Sanity blog) […]

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