Reposted from the NoTricksZone
By P Gosselin on December 23, 2020
From the cold sun
(Translated / edited, subheadings by P. Gosselin)
Der Spiegel has an internal columnist for climate problems: Stefan Rahmstorf from PIK Potsdam. His latest trick: “Why the sea level is rising faster and faster”. In the introduction he writes with reference to data:
The rate of increase has doubled from 2.1 to 4.8 mm per year during this period. "
We want to check that and find something: the European data from “Copernicus”. They cover the period from 1993 to March 2020 and are therefore very new. Now we look for the trend increase claimed by Rahmstorf and calculate 5-year trends of the global measured values up to the year plotted on the abscissa:
Fact: No long-term trend change
Indeed, we are seeing a trend increase: if the 5-year trends up to 2003 were fairly accurate at 3mm / yr, they fell to 2011, after which they rose to the value Rahmstorf mentioned up to 2015, and then fell again they had a little over 3mm / year at the beginning.
Has the long-term trend changed? No, from 1993 until today it is exactly 3 mm / year.
Rahmstorf's seedy use of statistics
Does the internal variability play a role that influences the (climatically) still quite short data set from 1993-2019 (complete years) in such a way that you can interpret all sorts of things into it if you want?
We find a note where Rahmstorf is linked to the data, but we need to look at the history of the University of Colorado website:
Not a serious oceanographer
In 2013 (after a strong La Nina event in 2012) it was shown there how the rise in sea level depends on La Nina and El Nino (ENSO for short).
After the La Nina in 2012 there was an El Nino in 2016, which explains the highlight in the picture above. What Rahmstorf describes in a bold subheading of his article “Spiegel” as a “consequence of fossil fuel consumption” (namely as a trend increase in sea level rise) is actually the result of ENSO's natural variability? We cannot accept this from a serious oceanographer (his job title).
Rahmtorf disagrees with a new peer-reviewed paper
We are therefore engaged in peer-reviewed science and come across a recently published paper in the Journal of Geodetic Science (Iz & Shum 2020). The authors examine much more carefully than before with the data set of satellite-based observations of the sea level and find many natural forcing variables that suggest a certain acceleration of the short data set.
The authors conclude that assessments of future trends “should be made with extreme caution”.
Rahmstorf doesn't do this when he later concludes, "Houston, we have a problem." What follows from Rahmstorf is the always familiar story: turning points of the Greenland ice, etc., etc. Again it ends with the familiar:
The next two decades will determine how many island states will sink and how many coastal cities will be flooded. "
You can write something like this, but it has nothing to do with science at all.
Sloppy journalism from Spiegel? "Embarrassing"
The "Spiegel" should correctly label the Rahmstorf article as "a citizen's opinion" because it is nothing more. He does not report on the state of the art nor does he show the uncertainties of his own conclusions.
Embarrassing for an oceanographer.
Addendum from CR: Background information on Rahmstorf
Ultimately, the secret of cream smoothing is that it is a triangular filter with linear padding. All the high-Falutine talk about "embedding dimension" and "nonlinear … lines" is just fluff. All claims of doing something "new" are false, as is Rahmstorf's claims that he did not use "padding". Rahmstorf's shift from M = 11 to M = 15 is just a shift from a triangular filter to a wider triangular filter – it is not inappropriate to speculate on the motive for the shift, given the rhetorical appearance of the smoothed series.
After all, I don't think the team has been able to successfully assert a copyright interest in the triangle filter (
The Team) .Steve McIntyre
Apart from the controversy about the smoothing of algorithm parameters by real climatists, another interesting aspect of Figure 3 of the Copenhagen synthesis report is the cones of the model projections. Today I'm going to show you how to do a similar comparison on an AR4 model of your choice. Unlike Rahmstorf, I'll show how this is done, including turnkey codes. I understand that this is not in accordance with the GARP (General Accepted Realclimatescientist Procedure), but even Realclimatescientists who publish in peer-reviewed literature should be responsible for their methodology.
Here is Figure 3 from the Copenhagen Synthesis Report. I'm assuming the gray cone is the spread of model projections – note that the label says these are from the third assessment report. Raising the question – why the third evaluation report? Wouldn't the fourth evaluation report be more relevant?