The latest Intergovernmental Panel on Climate Change assessment report claims that the rate of sea level rise from 1993 to 2010 was roughly twice that from 1901 to 2010, offering one of the strongest reasons for alarm about anthropogenic global warming. But a major review by Kenneth Richard of recent journal publications on the subject finds little to no basis for the claim.

Says Richard:

According to the IPCC (2013), sea levels rose at a rate of 1.7 mm/year (6.7 inches per century) for the 1901 to 2010 period, but 3.2 mm/year (12.6 inches per century) during the 18-year period between 1993 to 2010, a rate similar to that obtained from 1920 to 1950.

If sea levels truly were rising at rates of 3.2 mm/year between 1993 and 2010 as the IPCC (2013) claims with high confidence, then the thermal and ablation sources for that sea level rise should at least somewhat closely add up to 3.2 mm/year for the same period.  But if the sources for the sea level rise as determined by published studies only reach between 0.8 and 1.6 mm/year when added together – a quarter to half of the 3.2 mm/year claimed – then that suggests that there is something seriously questionable about the 3.2 mm/year sea level rise estimates for 1993 to 2010 obtained by satellite altimetry.

What follows is an abridged list of recent papers showing that sea level rise estimations claimed by the IPCC are likely highly exaggerated.

Then follows a painstaking review of the papers the gist of which Richard sums up thus: “Source data studies indicate recent only 0.8 – 1.6 mm/year sea level rise” (i.e., <6.7 inches, perhaps <3.4 inches, per century).

Not surprisingly, it appears that data adjustments are largely to blame for exaggerated claims of sea level rise, as Jo Nova reports.

Now, in the spirit of Peter Falk’s Columbo, “Just one more thing.” One recent paper claims that sea level rise could put 13.1 million Americans at risk by 2100. There are lots of problems with that, as Eric Worrall points out at WattsUpwithThat.com, including that the author ignores history, technological progress, and the failure of climate models. One glaring problem, though, is that the 13.1 million number rests on the assumption of sea level rise of 1.8 meter, i.e., 10 to 20 times the likely rise of 0.8 to 1.6 mm/year (0.08 to 0.16 meter per century). Indeed, even the author’s more restrained projection of 4.2 million displaced by a sea level rise of 0.9 meter by 2100 assumes ~6 to ~11 times the likely rise.

 

 

Featured image, “Netherlands–Enclosing Dyke,” courtesy of Roger W., Flickr Creative Commons, shows the Afsluitdijk (enclosing dyke), completed in 1932, the North Sea on the left, where the water level is higher, and the Ijsselmeer (also known as the Zuider Zee), where the water level is lower, on the right.