Sea level rises down 30 per cent. Still waiting for Robyn Williams’ 100 metres
Sea level rises were the great bogeyman of the warmists. Take this 2007 scare from ABC science presenter Robyn “100 metres” Williams:
Andrew Bolt: I’m telling you, there’s a lot of fear out there. So what I do is, when I see an outlandish claim being made…, Tim Flannery suggesting rising seas this next century eight stories high, Professor Mike Archer, … dean of science, suggesting rising seas this next century of up to 100 metres, or Al Gore six metres…. I ask you, Robyn, 100 metres in the next century…do you really think that? Robyn Williams: It is possible, yes. The increase of melting that they’ve noticed in Greenland and the amount that we’ve seen from the western part of Antarctica, if those increases of three times the expected rate continue, it will be huge.
But a new paper concedes sea level rises have in fact slowed to a rate that, if sustained, would give us rises this century of not 100 metres but just 24cm:
Present-day sea-level rise is a major indicator of climate change. Since the early 1990s, sea level rose at a mean rate of ~3.1 mm yr?1. However, over the last decade a slowdown of this rate, of about 30%, has been recorded.
The researchers (Cazenave et al., published by Nature Climate Change), seem more convinced by their warming theories than by evidence, and blame temporary natural factors for masking the real rise they expect:
We find that when correcting for interannual variability, the past decade’s slowdown of the global mean sea level disappears, leading to a similar rate of sea-level rise (of 3.3 ± 0.4 mm yr?1) during the first and second decade of the altimetry era.
(Which, by the way, would still give us – if sustained – sea level rises this century not of 100 metres but 33cm.) Professor Judith Curry, Professor and Chair of the School of Earth and Atmospheric Sciences at the Georgia Institute of Technology, isn’t buying:
Recall this figure from AR5 on 20th century sea level rise: Consider the following statements from Cazenave regarding global sea level rise:
the 20th century average is 2 mm/yr, observations from 1992-2002 are 3.4 mm/yr observations from 2003-2011 are 2.4 mm/yr when corrected for an abundance of La Ninas, sea level rise from 2003-2011 is ‘adjusted’ to 3.3 mm/yr
…I don’t think there is any objective/convincing way to filter out the effects of El Nino/La Nina. They seem to be an intrinsic part of sea level variations, as is the PDO/AMO on multidecadal time scales. Can someone then tell me how you can infer that sea level rise is accelerating due to AGW, when compared with sea level rise for the first half of the 20th century? It is clear that natural variability has dominated sea level rise during the 20th century, with changes in ocean heat content and changes in precipitation patterns. Once again, the emerging best explanations for the ‘pause’ in global surface temperatures and the slow down in sea level rise bring into question the explanations for the rise in both in the last quarter of the 20th century. And makes the 21st century of sea level rise projections seem like unjustified arm waving.
Larry Hamlin at Watts Up With That adds:
The slowing in the measured rate of sea level rise during the last decade has occurred while the RSS satellite measured global lower-troposphere temperature record now has more than half of its 35+ year temperature record, which began data collection in January 1979, showing no global warming whatsoever since August 1996 as demonstrated in the graph below taken from an article in Real Science addressing this “pause”.