By Anthony Watts – Re-Blogged From http://www.WattsUpWithThat.com
We’ve been told over an over again that global warming would melt the icecaps, and melt Greenland, and that would result in catastrophic sea level rise flooding cities. We’ve also been told that “sea level rise is “accelerating” but in an investigation done here on WUWT by Willis Eschenbach, Putting the Brakes on Acceleration, he noted in 2011 that there seems to be no evidence of it at all, and notes that sea level was rising faster in the first half of the record.
Figure 1. Satellite-measured sea level rise. Errors shown are 95% confidence intervals. Data Source.
The smaller trend of the recent half of the record is statistically different from the larger trend of the first half. Will this reduction continue into the future? Who knows? I’m just talking about the past, and pointing out that we sure haven’t seen any sign of the threatened acceleration in the satellite record. Quite the opposite, in fact.
Pierre Gosselin, of “No Tricks Zone” has this excellent summary of what’s been going on since then. Excerpts below.
Over the past months a spate of scientific papers published show sea level rise has not accelerated like many climate warming scientists warned earlier. The reality is that the rise is far slower than expected, read here and here.
The latest findings glaringly contradict alarmist claims of accelerating sea level rise. For example the National Oceanic and Atmospheric Administration (NOAA) here wrote sea levels would “likely rise for many centuries at rates higher than that of the current century”, due to global warming.
In 2013 The Potsdam Institute for Climate Impact Research (PIK) wrote here sea-level rise in this century would likely be 70-120 centimeters by 2100″ (i.e. 7 – 12 mm annually) and that 90 experts in a survey “anticipated a median sea-level rise of 200-300 centimeters by the year 2300” (i.e. on average circa 7 to 10 mm every year).
Using these modelled estimates, the globe should now be seeing a rapid acceleration in sea level rise. Yet no evidence of this can be found so far. In fact the real measured data show the opposite is happening: a deceleration in sea level rise is taking place.
Instead of the 7 – 12 mm annual sea level rise the PIK projected in 2013, a recent study appearing in the Geophysical Research Letters in April 2017 corrected the satellite measured sea level rise downwards from 3.3 mm annually to just 3.0 mm over the past 24 years – or less than half what PIK models projected.
In another newly published paper by Frederiske et al. 2018 just this year, oceanographers estimate that global sea levels rose at a rate of only 1.42 mm per year between 1958 and 2014. That figure closely coincides with the results of Dr. Simon Holgate from 2007. According to the Holgate study: “The rate of sea level change was found to be larger in the early part of last century (2.03 ± 0.35 mm/yr 1904–1953), in comparison with the latter part (1.45 ± 0.34 mm/yr 1954–2003).”
The Holgate result was confirmed by another 2008 paper authored by Jevrejeva et al, which found the fastest sea level rise during the past 300 years was observed between 1920 – 1950 with maximum of 2.5 mm/yr.
In other words: global sea level rise has decelerated since the 1950s.
At less than 2 mm annually, sea level is rising at only one sixth of the 12 mm per year rate projected by the PIK in 2013.