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Shock! Climate models can’t even predict a linear rise

Posted By Joanne Nova On October 14, 2010 @ 1:28 am In Global Warming | Comments Disabled

SOURCE: Semi-Satirical News

Preschooler outdoes climate models

Back in 2001, little Alby Brushtail was just 4 when he predicted global sea levels for a decade by drawing a straight line through a graph. Today, Will Steffen, Director of the Climate Institute admits that global climate models are woeful at predicting sea levels in a story titled:Sea levels rising at top end of estimates”.

The failure of the sophisticated models is all the more baffling because by 2001,  global sea levels had been rising at the not-so-tricky, fairly steady rate of 3mm a year for the previous nine years. Despite this simple linear trend, even with the worlds best equipment and budgets of millions, the top experts only barely managed to predict future sea levels within their broad error margins.

In the end, they couldn’t outdo the four year old who drew the line in with an orange crayon in his preschool class and who simply said that the 3mm a year trend would “just keep going”.

For his remarkable success in 2001, Alby credited Mr Squiggle, but says he’s moved on now, and uses a ruler.*

Satellites have been measuring sea levels, on a global basis, with unprecedented accuracy, since 1992. They show that the seas have been rising roughly 3mm a year over the last 18 years. The most recent figures hint that, if anything, the trend has slightly slowed in the last four years.**

Look at that linear trend

Global Sea Level Change recorded by satellite at the University of Colorado at Boulder. Click on the graph to visit the site.

Not so satirical

Will Steffen is paid by the Australian tax payer, to provide the best, whole and complete information to the Australian public that he can. But it appears he chose not to tell Australians that global sea levels are showing absolutely no sign sign of upward acceleration. He spun a “business as usual” result into a hurry-don’t-wait message. And the Environment editor of The Australian didn’t seek out other opinions or bother to do the five minute web search that would have turned up the well recognized University of Colorado graph above.

Is this story anything other than one-sided PR dressed as reporting?

The phrasing is o-so-clever. Look for the weasel word “possible”:

“SEA levels are rising at the top of international estimates, making an increase of between 50cm and 1m possible over the next century.”

Possibly 1 meter? Why not 2 m, why not 10 m?

They’re too hard to get away with.

The Royal Society’s climate change summary said thermal expansion of the ocean made it very likely that for many centuries the rate of global sea-level rise per century would be at least 20cm.

(See, it will rise by a meter, and absolutely no later than the year …2500.)

Senior scientist John Church refers to a “long term” average of 2mm, but doesn’t say how long that long term average is, and doesn’t point out that sea levels have been rising at a similar rate for nearly a whole century before man-made emissions became significant (1945). The long term trend over the last 150 years remains remarkably constant.

Senior CSIRO scientist John Church this week launched a book that says sea levels are rising at about 3mm a year against a long-term average of 2mm a year. “We have been tracking sea level since 1993 and it is now at the upper end of the IPCC projections of 80cm by the end of the century,”

It doesn’t add up

And how do you get (!) 80cm from a 3mm a year trend running for 90 years? (90 x 3 mm is … 27 cm.)  As always with establishment climate types, there’s an exponential curve coming, somewhere… sometime… “trust us”. (Hey, and it’s not like they would hide uncertainties, fail to mention counter examples, or cherry pick the data sets is it?)

graph of glacier retreat and sea level rise out of the little ice age

Figure 2.

Glacier shortening[1] [2] and sea level rise[3]. Gray area designates simulated range of error in the sea level record. These measurements lag air temperature increases by about 20 years. So, the trends began more than a century before increases in hydrocarbon use. GRAPH from the global warming review by Robinson, Robinson and Soon.

[1] Oerlemanns, J. (2005) Science 308, 675-677.

[2] Jevrejeva, S., Grinsted, A., Moore, J. C., and Holgate, S. (2006) J. Geophysical Res. 111,2005JC003229. http://www.pol.ac.uk/psmsl/au thor_archive/jevrejeva_etal_gsl/

[3] Leuliette, E. W., Nerem, R. S., and Mitchum, G. T. (2004) Marine Geodesy 27, No. 1-2, 79-94. http://sealevel.colorado.edu/

*Note the Satirical News.

** “Satellites are accurate” (at least according to the University of Colorado — where I sourced that information from, but a sharp commenter -Brego @ #3 notes that they also say “Jason-1, … providing an estimate of global mean sea level every 10 days with an uncertainty of 3-4 mm”. Yes. Hmmm. 3-4mm?!

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