Finds sea levels have risen over the past 9 years [2002-2011] at a rate of only 1.7 mm/yr, equivalent to 6.7 inches per century, matching tide gauge data rates.
The paper corroborates the NOAA 2012 Sea Level Budget which finds sea levels have risen at only 1.1-1.3 mm/yr over the past 7 years from 2005-2012 [less than 5 inches/century], and the paper of Chambers et al finding “sea level has been rising on average by 1.7 mm/year over the last 110 years.”
From the IPCC FAR Chapter 5.5.2: Holgate and Woodworth (2004) estimated a rate of 1.7 ± 0.4 mm yr–1 sea level change averaged along the global coastline during the period 1948 to 2002, based on data from 177 stations divided into 13 regions. Church et al. (2004) (discussed further below) determined a global rise of 1.8 ± 0.3 mm yr–1 during 1950 to 2000, and Church and White (2006) determined a change of 1.7 ± 0.3 mm yr–1 for the 20th century.
The paper:
Impact of Continental Mass Change on Rate-of-Rise of Sea Level
Present-day continental mass variation as observed by space gravimetry reveals secular mass decline and accumulation. Whereas the former contributes to sea-level rise, the latter results in sea-level fall. As such, consideration of mass accumulation (rather than focussing solely on mass loss) is important for reliable overall estimates of sea-level change. Using data from the Gravity Recovery And Climate Experiment satellite mission, we quantify mass-change trends in 19 continental areas that exhibit a dominant signal. The integrated mass change within these regions is representative of the variation over the whole land areas. During the integer 9-year period of May 2002 to April 2011, GIA-adjusted mass gain and mass loss in these areas contributed, on average, to -(0.7 ± 0.4) mm/year of sea-level fall and + (1.8 ± 0.2) mm/year of sea-level rise; the net effect was + (1.1 ± 0.6) mm/year. Ice melting over Greenland, Iceland, Svalbard, the Canadian Arctic archipelago, Antarctica, Alaska and Patagonia was responsible for + (1.4±0.2) mm/year of the total balance. Hence, land-water mass accumulation compensated about 20 % of the impact of ice-melt water influx to the oceans. In order to assess the impact of geocentre motion, we converted geocentre coordinates derived from satellite laser ranging (SLR) to degree-one geopotential coefficients. We found geocentre motion to introduce small biases to mass-change and sea-level change estimates; its overall effect is + (0.1 ± 0.1) mm/year. This value, however, should be taken with care owing to questionable reliability of secular trends in SLR-derived geocentre coordinates.
A slide show on the paper is available here: Baur_GGHS2012
Reference
Baur, O., Kuhn, M. and Featherstone, W.E. 2013. Continental mass change from GRACE over 2002-2011 and its impact on sea level. Journal of Geodesy 87: 117-125.
Background
The authors write that “present-day continental mass variation as observed by space gravimetry reveals secular mass decline and accumulation,” and that “whereas the former contributes to sea-level rise, the latter results in sea-level fall.” Therefore, they state that “consideration of mass accumulation (rather than focusing solely on mass loss) is important for reliable overall estimates of sea-level change.”
What was done
Employing data derived from the Gravity Recovery And Climate Experiment – the GRACE satellite mission – Baur et al. assessed continental mass variations on a global scale, including both land-ice and land-water contributions, for 19 continental areas that exhibited significant signals. This they did for a nine-year period (2002-2011), which included “an additional 1-3 years of time-variable gravity fields over previous studies.” And to compensate for the impact of glacial isostatic adjustment (GIA), they applied the GIA model of Paulson et al. (2007).
What was learned
Over the nine years of their study, the three researchers report that the mean GIA-adjusted mass gain and mass loss in the 19 areas of their primary focus amounted to -(0.7 ± 0.4 mm/year) of sea-level fall and +(1.8 ± 0.6) mm/year of sea-level rise, for a net effect of +(1.1 ± 0.6) mm/year. Then, to obtain a figure for total sea-level change, they added the steric component of +(0.5 ± 0.5) mm/year, which was derived by Leuliette and Willis (2011), to their net result to obtain a final (geocenter neglected) result of +(1.6 ± 0.8) mm/year and a final (geocenter corrected) result of +(1.7 ± 0.8) mm/year.
What it means
The final geocenter-corrected result of Baur et al. is most heartening, as Chambers et al. (2012) indicate that “sea level has been rising on average by 1.7 mm/year over the last 110 years,” as is also suggested by the analyses of Church and White (2006) and Holgate (2007). Concomitantly, the air’s CO2 concentration has risen by close to a third. And, still, it has not impacted the rate-of-rise of global sea level!
References
Chambers, D.P, Merrifield, M.A. and Nerem, R.S. 2012. Is there a 60-year oscillation in global mean sea level? Geophysical Research Letters 39: 10.1029/2012GL052885.
Church, J.A. and White, N.J. 2006. A 20th century acceleration in global sea-level rise. Geophysical Research Letters 33: 10.1029/2005GL024826.
Holgate, S.J. 2007. On the decadal rates of sea level change during the twentieth century. Geophysical Research Letters 34: 10.1029/2006GL028492.
Paulson, A., Zhong, S. and Wahr, J. 2007. Inference of mantle viscosity from GRACE and relative sea level data. Geophysical Journal International 171: 497-508.
This essay was derived from several sources: CO2Science.org, The Hockey Schtick, and independent located content.
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Or we can stop adding to sea level rise by stopping our extraction of water from below ground.
Dams V Boreholes
Izen, unless observations show acceleration, I wouldn’t lose any sleep over this crap. Relax.
The supermoon last month produced the highest astronomical tide of the year at our place on the east coast of Australia and the level it achieved was exactly what it was 60 years ago.
2inches above the old sea wall built to AHD 1.1
Not much SLR here.
Here is the Sydney (Fort Dension) NSW Aust. records since 1914 http://www.bom.gov.au/ntc/IDO70000/IDO70000_60370_SLD.txt . Can you see any statistical increase? This monitoring site has one of the longest recorded records of tides and sea level.in the world.
Wait a minute. Predictions for the the East Coast of the US is 2 feet by 2050. Some explanations is the SLR is exponential so we won’t see it for a couple of decades. These models are accepted by a consensus of scientists so they can’t be wrong. Don’t confuse me with data.
@- Gail Combs
“And the plants will love it along with the added CO2 as the deserts go green”
IF it falls on the deserts.
Recent fooding in India, Canada and the Midwest indicates that the extra rain has not always arrived in a manner that improves agricultural yields.
Sometimes quite the opposite.
http://www.swnews4u.com/section/1/article/14298/
Along side the abstract of the paper is this information:
GMSL Rates: CU: 3.2 ± 0.4 mm/yr AVISO: 3.2 ± 0.6 mm/yr
CSIRO: 3.2 ± 0.4 mm/yr NOAA: 3.2 ± 0.4 mm/yr (w/ GIA)
Yet as this paper concludes and as Jimbo (above) quotes:
IPCC – Climate Change 2007 – AR4
Estimates for the 20th century show that global average sea level rose at a rate of about 1.7 mm yr–1.
Will someone explain this discrepancy? Or are these GMSL rates just plain alarmist exaggeration?
This was embargoed when I last inquired, but do go to Climate Audit, find the thread Econometric Applications in Climatology and futz around for a paper by Beenstock, Felsenstein, Frank & Reingewertz in the conference program guide. It’s but a couple of weeks old.
Re co-author of the cited Baur, O., Kuhn, M. and Featherstone, W.E. 2013. Continental mass change from GRACE over 2002-2011 and its impact on sea level. Journal of Geodesy 87: 117-125.
Will Featherstone was at Curtin University, West Australia, Surveying, so the paper will be of impeccable quality.
In other words, billions of dollars were wasted putting 5 different sea level measuring satellites into orbit because the scientists who collated the raw data just added 1.4 mms/yr to the numbers because of their belief systems.
The science has a rotten tendency to do this with all base climate data.
It wouldn’t be that big of a problem if we weren’t changing our whole civilization based on these belief-driven adjustments.
Doesn’t the graphic show the coriolis effect and that water is just sloshing around under lunar orbital influence? They presume lunar influence is smoothed out over 29.5 days but ignore numerous important cycles including 18.11 year Saros Cycle, 18.6 year Nodal Cycle, 19 year Metonic Cycle.
@- Paul80
“Along side the abstract of the paper is this information:
GMSL Rates: CU: 3.2 ± 0.4 mm/yr AVISO: 3.2 ± 0.6 mm/yr
CSIRO: 3.2 ± 0.4 mm/yr NOAA: 3.2 ± 0.4 mm/yr (w/ GIA)
Estimates for the 20th century show that global average sea level rose at a rate of about 1.7 mm yr–1.
Will someone explain this discrepancy? Or are these GMSL rates just plain alarmist exaggeration?”
The 1.7mm/yr is the long term average over {at least} the last fifty years.
The 3.2mm/yr is the satellite measurement over the recent past.
This is why some scientists are claiming that the rate of sea level rise has doubled and the AR4 estimates are far too low as well as omitting the contribution from increasing ice melt.
This is a significant finding.
As there is no change in the rate of rise of the oceans’ level supports the assertion that heat cannot be hiding in the oceans.
The fact that there was been 16 years of no change in planetary temperature appears to indicate that there is/are one or more fundamental errors with the greenhouse gas warming mechanism in addition to the fact that the planet resists forcing changes (negative) feedback rather than amplifying forcing changes.
Can somebody tell me whether the present state of England’s Cinque Ports, which are now high and dry but were at sea level in medieval times, was caused by retreating sea level or by upthrusting of the terrain?
@- Bill Illis
“It wouldn’t be that big of a problem if we weren’t changing our whole civilization based on these belief-driven adjustments.”
The ‘belief’, which is rather well supported by empirical observations, is that the changing climate will impose far worse changes on our whole civilisation and that the intelligent thing to do is prevent as much of the change as possible and adapt to the unavoidable damage the present changes are causing.
This is an alternative to propagating the belief that the scientific case for mitigation and adaption is a political conspiracy. With the consequent Panglossian inference that the status quo is the best of all possible worlds….
Where does that leave the University of Colerado with their 3.2mm +/- 0.4mm per year?
http://sealevel.colorado.edu/
Maybe their various “corrections” account for their near doubling of the annual rate.
Maybe they would like to comment here. No chance.
You can squeeze a tennis ball in your hand.So does the Earth naturally expand and contract with sissmic activity under the oceans and on the coasts .So how does that make the sea level appear to go up and down.
@- Richie
Can somebody tell me whether the present state of England’s Cinque Ports, …
Old Whinchelsea is now underwater, but the other Cinque ports were river ports which have silted up as a result of river sediments and coastal deposition from the channel tidal eastward drift.
The tectonic changes have mainly been glacial rebound in the North causing subsidence in the south, but this has not been sufficient to offset the rise in coastal land from sedimentation on the English south coast.
The tide gauges on average are measuring 1.4 mms/yr of sea level rise. [Because the coastlines are rising by 0.3 mms/yr due to ice age rebound and general continental drift changes, one could argue that the volume of sea level is rising at 1.7 mms/yr, but it is only 1.4 mms/yr where we live on land and that is what matters. I guess it might matter more to islands which are anchored to the ocean crust but these islands at risk are not generally in the locations where the majority of ice age rebound is occuring, causing the ocean crust to sink back – just a few which are also on continental shelf margins in the lower latitudes].
For unknown reasons, the satellite raw data adjustment algorithms have sea level rise at 2.9 mms/yr (and 0.3 mms/yr is added for the average land rise versus the ocean depth).
I downloaded all the tide gauge data from the Permanent Mean Sea Level Service (PMSL) and the average is rising at just 1.4 mms/yr (now this is the average of all guages in the database – it will not be a true mean sea level rise because there will be individual gauges moving into and out of the database each year but there are just so many at any one time, its hard to imagine how this fact could change the trend, but caveat required].
All 31,000 annual tide gauge observations going back to 1807. [Note there are some general groups that are rising quickly and some groups that are falling but this is due to ice age rebound where some geographic places are rising at 10 mms/yr for example but other locations are falling at 3.0 or 4.0 mms/yr].
On average since 1807, the tide guages are increasing by 0.28 mms/yr.
http://s17.postimg.org/si6ly8q27/Sea_Level_Measurements_PMSL.png
If we zoom into the 1930 to 2009 period, we see that the general trend remained at 0.29 mms/yr until about 1980. (A possible 60 year cycle impacting it). After 1980, the trend rises to 1.4 mms/yr. I don’t see any acceleration in this rate since 1980.
http://s2.postimg.org/xcp9tsz6x/Sea_Level_Measurements_PMSL_1930_1980_2009.png
Now compared to some other sea level reconstructions including the satellite altimetry outlier.
http://s8.postimg.org/9ysbkpw51/All_Sea_Level_Measurements_1960_2013.png
@Patrick Guinness
By reading first Potsdam report at the beginning, I found this sentence:
„The present CO2 concentration is higher than paleoclimatic and geologic evidence indicates has occurred at any time in the last 15 million years.”
The “reference” the report I found only one work on the subject – A.K. Tripati of 2009. Since that time was established, however, some fundamental papers (which should be of interest to the authors of the report) saying (at least partly) different than the A.K.T., for example, Pagani (2010) and especially Seki (2010. Alkenone and boron-based Pliocene pCO2 records)
Recently work Tripati has once again been strongly confounded (http://www.ldeo.columbia.edu/~polissar/teaching/F2012_G9600_Climate_Puzzles_of_the_Neogene/LaRiviere_etal_2012_Suppl.pdf): “… we consider it premature to apply the B/Ca to long (myr) reconstructions of past pCO2, as Tripati et al.9 did. For these reasons, we have excluded the abovementioned records from Figure 1. However, the uncertainties associated with these estimates are too large to constrain the pCO2 changes of the past 15 myrs. For this reason we have excluded these estimates from Figure SI 1 and Figure 1.”
Of course, this figure is worth seeing …
The last Potsdam report threaten us heat waves and tropical cyclones (as a result of global warming).
The current warming should be comparable to the Eemian – Sangamon and Holocene maximum.
Eemian and mid-Holocene (6,000 years ago and the last interglacial period 125,000 years ago – http://blog.chron.com/climateabyss/2011/12/dispatch-from-agu-an-equable-climate-curveball/).
“So in both seasons [mid-Holocene 6,000 years ago and the last interglacial period 125,000 years ago], the detectable segment of the pole-to-equator temperature difference was smaller than at present, and at high latitudes the seasons were less dramatic than at present.”
“According to Davis and colleagues, the higher latitude continents north of 50N in both periods [max. Eemian, mid-Holocene] were much warmer than present-day climate in winter, not so much warmer in summer. “Climate models don’t do this.” „… they are generally too warm on summer …”
It is now time for my “cherry”:
Tom Knutson (2008, 2013 – http://www.gfdl.noaa.gov/global-warming-and-hurricanes/) write:
“Turning to future climate projections, current climate models suggest that tropical Atlantic SSTs will warm dramatically during the 21st century, and that upper tropospheric temperatures will warm even more than SSTs. Furthermore, most of the models project increasing levels of vertical wind shear over parts of the western tropical Atlantic (see Vecchi and Soden 2007). Both the increased warming of the upper troposphere relative to the surface and the increased vertical wind shear are detrimental factors for hurricane development and intensification, while warmer SSTs favor development and intensitification. To explore which effect of these effects might “win out”, we can run experiments with our regional downscaling model.”
Is the experiments are necessary?
Soelen (2012, http://hol.sagepub.com/content/early/2012/02/28/0959683611434226.abstract): „Throughout the record, indications for storm activity can be recognized as coarser grained layers consisting of quartz sands or shell debris. These layers are rare during the mid Holocene [warm period], but between 3.2 and 2 kyr BP [cool period], their numbers increase, suggesting an increase in tropical cyclone activity in the Gulf of Mexico.”
The most frequent changes in the amplitude of the global sea level is 70-75 cm (Holocene).
… but Southeast Asia during the Holocene natural repeatedly experienced much more sudden changes in sea level. Worth reading this work:
Holocene weak summer East Asian monsoon intervals in subtropical Taiwan and their global synchronicity (Selvaraj, 2008): “… believed to be driven by coupled ocean-atmosphere interactions, especially reduced heat and moisture transport and enhanced El Nin˜o-Southern Oscillation in the tropical Pacific, as well as solar activity.” What causes: “… abrupt changes witnessed in other paleorecords …”
Conclusion: Reports Potsdam is a typical example of an alarmist “cherry picking” in its extreme form – an opportunistic use of science to economic and political objectives.
The question therefore arises: will prepare infrastructure shores of South East Asia (for the change), or perhaps the same money spent fuel concerns in geo-sequestration of CO2 – as it does (and want to do more of it) UN and EU?
If you got to the Internet Archive’s WayBack Machine:
http://archive.org/web/web.php
and plug in the URL for Colorado Universty’s Sea Level Research Group
http://sealevel.colorado.edu/
You will find records that go back to 2004
The earliest functional “mean sea level time series” link is from
March 27th of that year, and if you follow that link through to “Inverted Barometer Applied” and “Seasonal Signals Removed” and click on text
http://web.archive.org/web/20040413231515/http://sealevel.colorado.edu/2004_rel1.2/sl_ib_ns_cu2004_rel1.2_global.txt
you will find the data as it existed for 1992.928 thru 2003.842 It’s then rather simple to download the series into Excel and find the slope. It comes out to be 2.6 mm/yr
If you then go to Colorado University’s Sea Level Research Unit today and dowload the “Raw data (ASCII)”
http://sealevel.colorado.edu/files/2013_rel4/sl_ns_global.txt
You will find that the same series for 1992.96 through 2003.846 comes out to be 3.5 mm/yr
Somehow over the last ten years the data has been changed. What had been 2.6 mm/yr in 2003 is now 3.5 mm/yr. An increase of 0.9 mm/yr.
If you ask Colorado University about these changes they say:
—
The sea level time series release from 2004 is over eight years old, and in that time many parts of the TOPEX and Jason-1 processing have been updated to reflect instrument and ancillary data improvements. Without recreating each processing change over the last eight years, We cannot point to any specific update that is the main cause of the differences between the 2004 and the current release. But a partial list of the more influential updates include:
– updated orbits
– updated radiometer corrections
– updated tide models
– updated sea state bias models
– updated dynamic atmosphere
A review of the release notes shows how we continually apply what the altimeter science community considers to be the most up-to-date set of processing parameters.
—
Without further comment the above stands as its own testimony.
If you got to the Internet Archive’s WayBack Machine:
http://archive.org/web/web.php
and plug in the URL for Colorado Universty’s Sea Level Research Group
http://sealevel.colorado.edu/
You will find records that go back to 2004
The earliest functional “mean sea level time series” link is from
March 27th of that year, and if you follow that link through to “Inverted Barometer Applied” and “Seasonal Signals Removed” and click on text
http://web.archive.org/web/20040413231515/http://sealevel.colorado.edu/2004_rel1.2/sl_ib_ns_cu2004_rel1.2_global.txt
you will find the data as it existed for 1992.928 thru 2003.842 It’s then rather simple to download the series into Excel and find the slope. It comes out to be 2.6 mm/yr
If you then go to Colorado University’s Sea Level Research Unit today and dowload the “Raw data (ASCII)”
http://sealevel.colorado.edu/files/2013_rel4/sl_ns_global.txt
You will find that the same series for 1992.96 through 2003.846 comes out to be 3.5 mm/yr
Somehow over the last ten years the data has been changed. What had been 2.6 mm/yr in 2003 is now 3.5 mm/yr. An increase of 0.9 mm/yr.
If you ask Colorado University about these changes they say:
—
The sea level time series release from 2004 is over eight years old, and in that time many parts of the TOPEX and Jason-1 processing have been updated to reflect instrument and ancillary data improvements. Without recreating each processing change over the last eight years, We cannot point to any specific update that is the main cause of the differences between the 2004 and the current release. But a partial list of the more influential updates include:
– updated orbits
– updated radiometer corrections
– updated tide models
– updated sea state bias models
– updated dynamic atmosphere
A review of the release notes shows how we continually apply what the altimeter science community considers to be the most up-to-date set of processing parameters.
—
Without further comment the above stands as its own testimony.
But they didn’t account for Rahmstorf’s calculation of an acceleration of sea level presently visible.
I wouldn’t think the TRF problem is not pertinent here since it is comparing GRACE data to GRACE data. And, unlike the silly claims of Izen, the 2002-2011 period makes this quite recent.
The water being pumped out of aquifers is probably much more than any increases to land water. This would mean the actual rise is much less (maybe half as much).
I got a kick out of Izen’s silly mentioning of floods in the Midwest US since that is the very region that had a drought last year. The average of the two years is right around normal.
Does anyone else get the feeling that Izen is in full panic. The pure denial in all his comments is extraordinary.
Typo .. s/b “I would think …”
A truly objective observer would conclude, quite simply, from the combination of tidal gauge data and confirmation of the Grace data, that there is no effect from the increase in CO2 on the natural rate of change coming out of the little ice age.
Which somewhat begs the question of how the “Missing Heat” that seems to have eluded Kevin and Co. since ~1997, and having, despite the laws of convection, managed to slink undetected through the – cooling since the beginning of the century – sea surface, has managed to sequester itself the deep oceans, without managing to cause any overt or accelerated expansion.
Clever stuff, this climate science.