The average sea rise over the last 7,000-8,000 years is 6-8 inches per century. As I’ve explained before, we use the 7,000-8,000 year figure due to that being the time when the massive sea rise post-glacial period leveled out (relatively).
When we discuss averages, we have to consider that when the Earth is in a cool period sea rise will be low, if not negative, and must be higher during a warm period. Since the cool periods tend to last longer than the warm periods, then sea rise should be considerably more than the average. How’s that working out?
(Die Welt) A scientific study by the Hebrew University of Jerusalem has closely examined data from the measurement stations located mainly at the coasts and reached the result that sea level rise calculations were exaggerated upwards. In the study Michael Beenstock and colleagues reached the result that sea level rise on a global average is only 1 millimeter and that by the end of the century it will rise only 10 centimeters; only 1/3 of the stations showed a detectable rise, 61% showed no movement and 4% showed a drop.â€
10 centimeters equals 3.937 inches. Let’s call it 4. So sea rise isn’t even at average, but below. The average sea rise during the 20th Century was well within the historical averages discussed at the beginning, when it should have been much higher. The 2007 UN IPCC estimate was for 18 to 59 cm (7.1 to 23 in). Which would have still put sea rise at a range going from purely average to a bit above what one would expect during a big warm period.
The article and translation comes via No Tricks Zone, which notes
Overall 1 mm/year is about 67% less than what Jason TOPEX satellite altimetry is showing (3 mm). If anything, Beenstock’s result indicate a sea level rise slowdown.
Beenstock is not the only scientist who has found sea level rise is much slower than believed. Kulke writes that other peer-reviewed studies reach similar conclusions. For example Nicola Scafetta of Duke University (see full paper here) shows that sea level is subject to 60-year cycles and concludes that the human impact on sea level is too small and is statistically insignificant.
Lest one think Kulke is a raging skeptic, he takes the view that there is a human fingerprint on the climate via CO2, but that it has been highly exaggerated.
Back in July, 2013, Anthony Watts blogged a study using GRACE data to highlight that global sea rise was around 6.7 inches per year. So, purely average.
