From the University of Southampton
What the past tells us about modern sea-level rise
Researchers from the University of Southampton and the Australian National University report that sea-level rise since the industrial revolution has been fast by natural standards and – at current rates – may reach 80cm above the modern level by 2100 and 2.5 metres by 2200.
The team used geological evidence of the past few million years to derive a background pattern of natural sea-level rise. This was compared with historical tide-gauge and satellite observations of sea-level change for the ‘global warming’ period, since the industrial revolution. The study, which was funded by the Natural Environment Research Council (iGlass consortium) and Australian Research Council (Laureate Fellowship), is published in the journal Scientific Reports.
Lead author Professor Eelco Rohling, from the Australian National University and formerly of the University of Southampton, says: “Our natural background pattern from geological evidence should not be confused with a model-based prediction. It instead uses data to illustrate how fast sea level might change if only normal, natural processes were at work. There is no speculation about any new mechanisms that might develop due to man-made global warming. Put simply, we consider purely what nature has done before, and therefore could do again.”
Co-author Dr Gavin Foster, a Reader in Ocean and Earth Science at the University of Southampton, who is based at the National Oceanography Centre, Southampton (NOCS), explains: “Geological data showed that sea level would likely rise by nine metres or more as the climate system adjusts to today’s greenhouse effect. But the timescale for this was unclear. So we studied past rates and timescales of sea-level rise, and used these to determine the natural background pattern.”
Co-author Dr Ivan Haigh, lecturer in coastal oceanography at the University of Southampton and also based at NOCS, adds: “Historical observations show a rising sea level from about 1800 as sea water warmed up and melt water from glaciers and ice fields flowed into the oceans. Around 2000, sea level was rising by about three mm per year. That may sound slow, but it produces a significant change over time.”
The natural background pattern allowed the team to see whether recent sea-level changes are exceptional or within the normal range, and whether they are faster, equal, or slower than natural changes.
Professor Rohling concludes: “For the first time, we can see that the modern sea-level rise is quite fast by natural standards. Based on our natural background pattern, only about half the observed sea-level rise would be expected.
“Although fast, the observed rise still is (just) within the ‘natural range’. While we are within this range, our current understanding of ice-mass loss is adequate. Continued monitoring of future sea-level rise will show if and when it goes outside the natural range. If that happens, then this means that our current understanding falls short, potentially with severe consequences.”
Yet another example of extrapolation science: The only science known to mickey mouse scientists.
The lame stream media operates on the simple premise, ‘if it bleeds, it leads’, which is why we hear about extrapolation scientists so often.
IIRC, that would be 27 barleycorns. Yep:
$ units
2526 units, 72 prefixes, 56 nonlinear units
You have: 9 inches
You want: barleycorns
* 27.000047
/ 0.037036973
What’s GASTA?
Barleycorns were, of course, the basis for the English system of weights and measures dating back to Anglo-Saxon times. Three barleycorns to an inch. Since I brew beer, and since beer is clearly one of the most important technological achievements of mankind (probably responsible for saving more lives than penicillin, over the millennia) the barleycorn (especially when malted, coarsely ground, mashed, and fermented) is dear to my heart. Note well, a pound is 7000 grains, and what grain would that be? Barleycorn! From “the middle of an ear” no less (none of these short-changing end grains, no sir).
So why bother with these tedious metric and non-metric aggregations! Let’s measure mass and length in terms of barleycorns! If only we had some way of turning it into a standard for the time and electrical charge, as well…
GAST(A) = Global Average Surface Temperature (Anomaly). Also called SAT (Surface Air Temperature).
rgb
How many of us have ever seen a tidal gauge? I have and I defy anyone to discern millimetres of change on the algae, barnacle encrusted, fanworm skeletons etc etc covering the ‘gauge’. Secondly, just when during the tidal cycle are these measurements taken? I spent some time with the chief operational meteorologist in Vanuatu and discovered that ‘hit or miss’ takes on even new meaning. Anyone who wishes to learn more about sea level rise in Vanuatu should contact the Met Service there and ask for the records. You will find that historic records don’t exist. Oh, they did once, but they became ‘lost’. I can’t say anymore because I promised not to.
These idiots are so pathetic there are literally thousands upon thousands of locations around the globe that have little to no variation of sea side levels. Nederland (Holland) is not flooding. Every one knows Venice sinking (not being flooded) Mediterranean and European coasts all have structures thousands of years old that have not been swamped. Yet these people can say straight faced that we have all drowned by now. The scientists that said the arctic ice would have disappeared by last September should be dropped in a boat with a three week supply of food and fuel and told to boat home. Its insane and criminal that these people are allowed to make these statements. They should be heckled every time.
Research the Pharos of Alexandria ( Alexandria Light house ) and harbor.
There is more land there now than before.
To rgbatduke:
Of course, it’s cheating, but there is an urban legend that
pigs were made to fly in the 1950s. At least one pig had
a JATO unit attached and the enormous thrust resulted in
the pig going airborne briefly.
One would imagine that the resulting splat would have
featured pre-cooked bacon (from the rocket unit
exhaust cooking the pig while in flight).
Well why “just” within the natural range. Any number within the natural range is a just number; as good as any other in the range. Whether near the “extreme limits” of the natural range or not, says nothing whatsoever about the frequency of occupation of those extreme values. They could occur more often, than some “Extreme” value buried deep in the middle of the normal range; after all, most numbers will be either larger or smaller than one in the middle.
Tom G(ologist) says:
December 12, 2013 at 12:05 pm
So much for their claim to have a scientific understanding of natural variation is sea level change.
rgb:
I’m preparing a summary of my findings (based on a geographically sparse, but demonstrably representative sampling of UHI-uncorrupted stations) for publication. It will be perhaps the first to show world-wide yearly estimates based entirely upon century-long, fixed-location records–without importing neighboring “anomalies” or “kriging” from afar and without any ad hoc “adjustments.” In other words, relying exclusively on actual measurements.
I’m preparing a summary of my findings (based on a geographically sparse, but demonstrably representative sampling of UHI-uncorrupted stations) for publication. It will be perhaps the first to show world-wide yearly estimates based entirely upon century-long, fixed-location records–without importing neighboring “anomalies” or “kriging” from afar and without any ad hoc “adjustments.” In other words, relying exclusively on actual measurements.
. The problem is that the inequality persists all the way down to fine grained length scales. (Equality only holds for a constant uniform temperature.) What this means is that radiative cooling terms in GCMs should have an additional cooling term proportional to the fourth cumulant of the surface temperature, basically the variance squared. Since surface temperatures are spatially inhomogeneous all the way down to meters or even less, one almost certainly underestimates the radiative cooling of any large patch with a single measured temperature assigned to the whole patch.
I’m not sure about being “the first” — for example:
http://www.appinsys.com/GlobalWarming/GW_Part3_UrbanHeat.htm
and I recall the issue and supporting data appearing on WUWT sometime in the last four or five years. I also vague remember seeing something on the subject perhaps on John Daly’s site long ago.
I don’t really have any problem with kriging, personally, as long as it is done in such a way that it doesn’t materially affect the direct average. You cannot create information with a krige, you can only use the information that’s already there in the data, and it is very difficult indeed to argue that a straight (e.g. area weighted) average isn’t information-theoretically optimal in that regard.
I do have a bone to pick with granularity, though. I may even try to write it up as an article over Christmas as I think I can manage a renormalization computation that shows that any sort of coarse grained estimate of cooling rates strictly underestimates them because
rgb
I have no idea why that didn’t work. It’s supposed to say ^4 (T average to the fourth) is strictly less than (T to the fourth average). The same principle is used to show that the GHE observed from the greybody temperature is a LOWER BOUND because if one accounts for the Earth’s rotation and makes the Earth ‘s temperature distribution inhomogeneous it loses heat faster and COOLs the Earth.
rgb
>Though to be fair to alarmism the Thames barrier was built to stop the increase flooding.
So apparently it’s working. Thank you, London!
rgb:
Nowhere do I claim being the first to recognize UHI effects or to value intact long-term records. My “perhaps first” remark applies to the specific method I use to construct necessarily coarse-grained, but geographically representative, century-long estimates of average temperature for all continents save Antarctica. Based on experience, I do have a problem with kriging over long distances across climate zones. And granularity in GCM calculations is quite a different matter than spatial granularity of time-series, whose cross-spectral relationships are easily established.
Thank you for your interest, nevertheless.