Frank Lansner’s first graph surprised me. It’s well known and often quoted that sea levels have been rising by 2-3mm a year every year for the last 20 years. But it’s not well known that the original raw satellite data doesn’t show that at all.
What astonished me was the sea levels first recorded by the Topex Poseidon satellite array showed virtually no rise at all from 1993-2001. Surely not, I thought. I asked sea-level expert Nils Axel-Morner, and he confirmed: “Yes, it is as bad as that.“ Now, given that Envisat (the European satellite) showed no rise from 2003-2011 (until it was adjusted) that means we have almost 20 years of raw satellite data showing very little rise.
We thought satellites would finally give us a definitive answer on sea levels. Instead, like the tide gauges, and every other tool available to mankind, apparently satellites systematically underestimate the rising trends. And despite the speed of light being quite quick and all, it can take years for the data to finally arrive. Sometimes 4 or 5 (or 10 years) after the measurement was made scientists “discover” that it was wrong.
Now of course, any one of these adjustments could be for very legitimate reasons and give us results closer to the truth. But the adjustments always bring data closer to the modeled trend. It’s decidedly non-random. Either there is a God who thinks teasing climate scientists is spiffy, or else there is something fishy going on, and some investigative journalists need to ask some investigative questions. Is that sea-level rise due to global warming or is it due to global adjustments?
Guest Post by Frank Lansner
Edited by Jo Nova
Sea levels – the raw data is always adjusted upwards
Fig 1 The data for recent years has gone through significant changes. In Morner 2004 the raw satellite data for sea level rise was shown with the original slope (the grey line with dots named “Topex/Poseidon as of 2001” above).
The data was shown in the Morner 2004 peer reviewed article. It does seem that Morner was simply presenting data on sea levels as they were known at the time. In addition, Holgate’s data from 2006-7 also seems to show a similar flat trend after 1994.
Holgate’s flat sea level graph ends in 2004 – when Envisat starts out with yet another dataset showing flat trend. The Envisat data is stitched so that 2004-6 overlaps with the satellite data. (But it could have been aligned with the original raw data of Topex/Poseidon, so that Envisat continues where Holgate 2007 ended.)
Fig 2.The original red graph is from the IPCC AR4 dataset (Church and White 2006). Other datasets for sea level rise have been added to show the trends as they were reported at the time with the year each one was released.
Something happened to the sea level data from satellites around 2004-2005 it seems, because in 2005 Morner points out that the satellite data has been changed significantly. The trends don’t look like they did before 2004.
Fig 3 The changes in sea level on a century scale still had a problem around 2006-7: Sea level data still did not support the global warming argument.
Even the results of Jevrejeva 2006 are a problem for the theory of man-made global warming. The annual sea level rise in the 1990’s were equal to the annual sea level rise of the 1940’s. That would suggest same global temperature trends for the two periods. That does not support the alarm over global warming.
Finally in 2009 Vermeer and Rahmstorf produced a dataset for sea level rise that actually suggested that annual sea level rise in the 1990’s exceeded the 1940’s rate and thus suggested warming was increasing faster now than it was in the 1940’s. This was the first time that a dataset for sea-level rise was produced that actually supported the global warming argument.
Meanwhile, sea level data from Envisat keeps coming in, and it seems that the new project staff have no idea they have to produce global warming adapted data:
Fig 4. As always there is some kind of adjustment making data a little more GW friendly, but still, the adjusted version of Envisat shows a tiny slope of around 6-7 cm per century… (the unadjusted showed 3 cm per century.)
European Satellites need upward corrections too
Fig 5: The European Envisat data before (in black) and after (in red)
After the Envisat stopped transmitting, the whole series was changed dramatically. In addition, the full length of the data beginning in 2002 is now shown. It appears that Envisat data from 2002-4 shows a fall in sea level, but this dive was not shown until now when the new stronger increase in sea level dominates the picture.
Note from Jo: The excuses for the upwards adjustments stretch credulity. One of the sea-level adjustments that increases the trend is a “correction” for rising land (globally) – Seriously: 10% of recorded sea level rise is conmpensation for the land apparently rising too. In any case, even if sea-levels are rising still (could be), they started rising long before we started using coal to produce electricity, see It wasn’t CO2: Global sea levels started rising before 1800. And in the case of Australia, Australian sea level rises exaggerated by 8 fold (or maybe ten) .
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IPCC Assessment Report 4, Working Group I, Chapter 9. [pdf]
Stoddart, D.R. and Reed, D.J. (1990) Sea-level rise as a global geomorphic issue, Progress in Physical Geography December 1990 14: 441-445, doi:10.1177/030913339001400401 [PDF]
Morner. N.A. Estimating future sea level changes from past records, Global and Planetary Change 40 (2004) 49–54 doi:10.1016/S0921-8181(03)00097-3 [PDF]
Holgate 2006 (poster version): [PDF]
Holgate, S.J. 2007. On the decadal rates of sea level change during the twentieth century. Geophysical Research Letters 34: 10.1029/2006GL028492 GRL: [PDF]
Morner N.A.: Memorandum by Professor Nils-Axel Mörner, Head of Paleogeophysics & Geodynamics, Stockholm University, Sweden President, (1999-2003) of the INQUA Commission on Sea Level Changes and Coastal Evolution, Leader of the Maldives Sea Level Project http://www.publications.parliament.uk/pa/ld200506/ldselect/ldeconaf/12/12we18.htm
Church, J.A. and White, N.J. 2006. A 20th-century acceleration in global sea-level rise. Geophysical Research Letters 33: 10.1029/2005GL024826. [eea.europa.eu]
Vermeer, M., and S. Rahmstorf, 2009. Global sea level linked to global temperature. Proceedings of the National Academy of Sciences. 106:6. PNAS (PDF)
Steven Goddard on Envisat:[real-science.com]
Watts/Goddard on Envisat: [WattsUpWithThat-April-2012]
Frank Lansner writes HideTheDecline, from Denmark.