From the NATIONAL CENTER FOR ATMOSPHERIC RESEARCH/UNIVERSITY CORPORATION FOR ATMOSPHERIC RESEARCH, and the department of “let’s not show a graph of sea level rise in the press release” comes this real PR spin job.
Climate change already accelerating sea level rise, study finds
Pinatubo eruption masked acceleration in satellite record
Courtesy of USGS.
BOULDER, Colo. — Greenhouse gases are already having an accelerating effect on sea level rise, but the impact has so far been masked by the cataclysmic 1991 eruption of Mount Pinatubo in the Philippines, according to a new study led by the National Center for Atmospheric Research (NCAR).
Satellite observations, which began in 1993, indicate that the rate of sea level rise has held fairly steady at about 3 millimeters per year. But the expected acceleration due to climate change is likely hidden in the satellite record because of a happenstance of timing: The record began soon after the Pinatubo eruption, which temporarily cooled the planet, causing sea levels to drop.
The new study finds that the lower starting point effectively distorts the calculation of sea level rise acceleration for the last couple of decades.
The study lends support to climate model projections, which show the rate of sea level rise escalating over time as the climate warms. The findings were published today in the open-access Nature journal Scientific Reports.
“When we used climate model runs designed to remove the effect of the Pinatubo eruption, we saw the rate of sea level rise accelerating in our simulations,” said NCAR scientist John Fasullo, who led the study. “Now that the impacts of Pinatubo have faded, this acceleration should become evident in the satellite measurements in the coming decade, barring another major volcanic eruption.”
Study co-author Steve Nerem, from the University of Colorado Boulder, added: “This study shows that large volcanic eruptions can significantly impact the satellite record of global average sea level change. So we must be careful to consider these effects when we look for the effects of climate change in the satellite-based sea level record.”
The findings have implications for the extent of sea level rise this century and may be useful to coastal communities planning for the future. In recent years, decision makers have debated whether these communities should make plans based on the steady rate of sea level rise measured in recent decades or based on the accelerated rate expected in the future by climate scientists.
The study was funded by NASA, the U.S. Department of Energy, and the National Science Foundation, which is NCAR’s sponsor.
Reconstructing a pre-Pinatubo world
Climate change triggers sea level rise in a couple of ways: by warming the ocean, which causes the water to expand, and by melting glaciers and ice sheets, which drain into the ocean and increase its volume. In recent decades, the pace of warming and melting has accelerated, and scientists have expected to see a corresponding increase in the rate of sea level rise. But analysis of the relatively short satellite record has not borne that out.
To investigate, Fasullo, Nerem, and Benjamin Hamlington of Old Dominion University worked to pin down how quickly sea levels were rising in the decades before the satellite record began.
Prior to the launch of the international TOPEX/Poseidon satellite mission in late 1992, sea level was mainly measured using tide gauges. While records from some gauges stretch back to the 18th century, variations in measurement technique and location mean that the pre-satellite record is best used to get a ballpark estimate of global mean sea level.
To complement the historic record, the research team used a dataset produced by running the NCAR-based Community Earth System Model 40 times with slightly different–but historically plausible–starting conditions. The resulting simulations characterize the range of natural variability in the factors that affect sea levels. The model was run on the Yellowstone system at the NCAR-Wyoming Supercomputing Center.
A separate set of model runs that omitted volcanic aerosols — particles spewed into the atmosphere by an eruption — was also assessed. By comparing the two sets of runs, the scientists were able to pick out a signal (in this case, the impact of Mount Pinatubo’s eruption) from the noise (natural variations in ocean temperature and other factors that affect sea level).
“You can’t do it with one or two model runs–or even three or four,” Fasullo said. “There’s just too much accompanying climate noise to understand precisely what the effect of Pinatubo was. We could not have done it without large numbers of runs.”
Using models to understand observations
Analyzing the simulations, the research team found that Pinatubo’s eruption caused the oceans to cool and sea levels to drop by about 6 millimeters immediately before TOPEX/Poseidon began recording observations.
As the sunlight-blocking aerosols from Mount Pinatubo dissipated in the simulations, sea levels began to slowly rebound to pre-eruption levels. This rebound swamped the acceleration caused by the warming climate and made the rate of sea level rise higher in the mid- to late 1990s than it would otherwise have been.
This higher-than-normal rate of sea level rise in the early part of the satellite record makes it appear that the rate of sea level rise has not accelerated over time and may actually have decreased somewhat. In fact, according to the study, if the Pinatubo eruption had not occurred–leaving sea level at a higher starting point in the early 1990s–the satellite record would have shown a clear acceleration.
“The satellite record is unable to account for everything that happened before the first satellite was launched, ” Fasullo said. “This study is a great example of how computer models can give us the historical context that’s needed to understand some of what we’re seeing in the satellite record.”
Understanding whether the rate of sea level rise is accelerating or remaining constant is important because it drastically changes what sea levels might look like in 20, 50, or 100 years.
“These scientists have disentangled the major role played by the 1991 volcanic eruption of Mt. Pinatubo on trends in global mean sea level,” said Anjuli Bamzai, program director in the National Science Foundation’s Division of Atmospheric and Geospace Sciences, which funded the research. “This research is vital as society prepares for the potential effects of climate change.”
Because the study’s findings suggest that acceleration due to climate change is already under way, the acceleration should become evident in the satellite record in the coming decade, Fasullo said.
Since the original TOPEX/Poseidon mission, other satellites have been launched–Jason-1 in 2001 and Jason-2 in 2008–to continue tracking sea levels. The most recent satellite, Jason-3, launched on Jan. 17 of this year.
“Sea level rise is potentially one of the most damaging impacts of climate change, so it’s critical that we understand how quickly it will rise in the future,” Fasullo said. “Measurements from Jason-3 will help us evaluate what we’ve learned in this study and help us better plan for the future.”
###
Compare the title of the press release to the title of the paper:
Is the detection of accelerated sea level rise imminent?
Abstract:
Global mean sea level rise estimated from satellite altimetry provides a strong constraint on climate variability and change and is expected to accelerate as the rates of both ocean warming and cryospheric mass loss increase over time. In stark contrast to this expectation however, current altimeter products show the rate of sea level rise to have decreased from the first to second decades of the altimeter era. Here, a combined analysis of altimeter data and specially designed climate model simulations shows the 1991 eruption of Mt Pinatubo to likely have masked the acceleration that would have otherwise occurred. This masking arose largely from a recovery in ocean heat content through the mid to late 1990 s subsequent to major heat content reductions in the years following the eruption. A consequence of this finding is that barring another major volcanic eruption, a detectable acceleration is likely to emerge from the noise of internal climate variability in the coming decade.
Access to open source article: http://www.nature.com/articles/srep31245
We have had some very good essays about the hoped for acceleration in sea level rise. Most recently this one in March of 2016:
An answer to: Is the rise in sea levels accelerating? by Jan Kjetil Andersen where he determines:
Above: IPCC AR5 page 289 their Figure 3.14
According to the figure, there has been no accelerating since 1920. We see that both Church & White and Ray & Douglas observe approximately the same annual rise of around 2.5 mm/year between 1920 and 1940, and then there is a fall 1 mm/year before the rate rebounds to 2.5 mm in the late 1980-ies.
The Jevrejeva et. Al observes a maximum rate of 4 mm/year in the 1940-es but the series stop before the increase in recent decades. Satellite altimeters shows a steady rise with a relative small variation between 2.9 and 3.9 mm/year.
The satellite measurements has a very short series in the figure because the series only goes from 1992 to 2012. That means that only two years can be calculated with an 18-years trend.
I think a very important piece of information comes out of this figure. We see here that in reality IPCC find no evidence for accelerating sea level rise after 1920. The rise before 1920 was real, but can hardly have been caused by the small amounts of greenhouse gases emitted at that time. The CO2 level in 1920 was according to Nasa 303 ppm, or just 10% above the pre-industrial level and the warming that could have caused the sea level rise has to come before that. (http://data.giss.nasa.gov/modelforce/ghgases/Fig1A.ext.txt)
And of course, Willis did an analysis back in 2011, Putting the Brakes on Acceleration, that is still germane today. This is the graph that NCAR won’t show you in their press release:
Figure 1. Satellite-measured sea level rise. Errors shown are 95% confidence intervals.Data Source.
Discover more from Watts Up With That?
Subscribe to get the latest posts sent to your email.
This reminds me of Willie Soon’s presentation to Doctors for Disaster Preparedness a couple years back,(https://www.youtube.com/watch?v=1gmW9GEUYvA). He is pretty convinced that the satellite data not accurate enough to tell us much and most of the hand waving about its implications are much ado about nothing.
There are a quite a few erupting volcanoes on the planet in any given period. Some of them smoke, bloop or blast depending on the day. So I guess what they are truly admitting is that volcanic activity should not be considered a constant in their climate models?
http://www.xkcd.com/1714/
I like this one better… http://volcano.si.edu/reports_weekly.cfm
Funny from http://earthobservatory.nasa.gov/IOTD/view.php?id=88459&eocn=home&eoci=iotd_readmore: “The heat arrived on the heels of an unusually long dry season and a 20-centimeter drop in local sea levels that lasted for a month, said Duke.”
Notice that sea level was 20cm below average for a month, and no headlines of drying harbours and climate change.
“Satellite observations, which began in 1993, indicate that the rate of sea level rise has held fairly steady at about 3 millimeters per year. But the expected acceleration due to climate change is likely hidden in the satellite record because of a happenstance of timing: The record began soon after the Pinatubo eruption, which temporarily cooled the planet, causing sea levels to drop.
The new study finds that the lower starting point effectively distorts the calculation of sea level rise acceleration for the last couple of decades.”
That’s some Gold Medal mental gymnastics right there.
:facepalm:
OMG Canal St in NYC is under 20 feet of water. And Florida has vast areas flooded. It’s just terrible. We all believe that, right? It must be true. I saw it in Mad Magazine last year, people were swimming to work right down Canal St. .
Yea, sure, with all the modern technology they just found this out now!
You know in Colorado recreational smoking of pot is legal. I suspect that those guys in Boulder are, well, as the song says, ” one toke over the line” . ( I think they are inhaling).
Recreational over-indulgence of pot could explain a lot of things in the last 7 yrs of the Obama exective branch.
I think one should read it in another way: It’s the first time that the mainstream admits that there is NO accelearation to measure. They blame it on pinatobu… you can forget about this. Next year there is another reason. The core is: There is no acceleration, admitted!
frankclimate,
“The core is: There is no acceleration, admitted!”
So too the “Pause”; admitted . . thing is, is is not what it once was . . We’re travelling through another dimension, a dimension not only of sight and sound but of mind; a journey into a wondrous land whose boundaries are that of imagination. That’s the signpost up ahead – our next stop, the Cagwit Zone!
Evidence~
JohnKnight
August 4, 2016 at 10:23 pm
Seth,
“I’m not pretending I think that. I’m saying that the sea level rise from anthropongenic climate change: currently a few centimetres, is problematic.”
Oh, yeah, the didn’t happen projected warming, that got canceled out by natural variation . . resulting in a few centimeters rise over what would have happened if the natural variation cooling had not been cancelled out by the virtual AGW . . Problematic is good term for that sort of sea level rise, I’ll give you that ; )
I am confused. First if Pinatubo erupted in 1991, cooling the oceans and regenerating ice, by 1993 when measurements started, the oceans would be lower – so wouldn’t the increase actually be more, not less? Secondly my understanding is that the satellites can measure a static ocean to an average of +-2 cm, let alone a wavy moving one. But if that is the case – assuming about 3.5 mm of rise a year we would have an 8 CM difference between 1993 and today, the error in measurement would be +- 4 cm. I am not sure there all this precision comes in. What can once discern from a 4 – 12 cm rise in 23 years? Not much.
“Satellite observations, which began in 1993, indicate that the rate of sea level rise has held fairly steady at about 3 millimeters per year.”
That’s only about 20 years. Tide gauge readings (raw data) at 22 sites globally that extend 120 years or more have been analyzed. This makes Pinatubo irrelevant.
https://wattsupwiththat.com/2014/04/25/the-elusive-60-year-sea-level-cycle/
The data not only does not support an increasing acceleration, it does not support an overall acceleration in the rate of sea level rise. The data DOES reveal that variations in the sea level, after accounting for a linear trend (~3 mm/year, or one foot per century), show only uncorrelated idiosyncratic variations that do not even have a discernible periodicity – anywhere.
You underestimate CAGW propensity for fixing the data. They can prove anything they want to. As we speak, CAGW scientists are hard at work adjusting numbers to fit the models. They have an imaginative crew.
You are probably right.
“This study is a great example of how computer models can give us the historical context that’s needed to understand some of what we’re seeing in the satellite record.”
“This study is a great example of how computer models can give us the *hysterical* context that’s needed to understand some of what we’re seeing in the satellite record.”
There. Fixed.
“Now that the impacts of Pinatubo have faded, this acceleration should become evident in the satellite measurements in the coming decade, barring another major volcanic eruption.”
Well we are hardly likely to see such a thing as a major volcanic eruption in the next decade are we?
It is amazing how they just buy arbitrary chunks of time. Whoops there goes another decade!!!!
In order to compare one sea level measurement against another via satellite wouldnt an accurate reading only be obtained when surface conditions are identical. Influences from high or low pressure systems, orbit and positioning of the moon and sun would need to be identical. Human adjustments wont cut it as they are obviously open to a lot of interpretation.
More NCAR *****.. what’s that word [that] gets me in the mod bin again.. cant remember
[Yes, but “htat” word also attracts attention. .mod]
“To complement the historic record, the research team used a dataset produced by running the NCAR-based Community Earth System Model 40 times with slightly different–but historically plausible–starting conditions.”
This is reasonable………to get an ensemble that provides a range of individual solutions as we do with climate/weather models. However, it’s not exactly clear how they managed to isolate the effect of the volcanic eruption 25 years ago in distorting the sea level acceleration that has been taking place, let’s say over the last decade.
They are saying that the rebound from Pinatubo in the 90’s caused a misleading, higher bounce in sea levels, that appeared to be part of an acceleration but really wasn’t and we should ignore the sea level acceleration in the mid/late 90’s and if we do, then the lack of sea levels accelerating since then does not really mean that sea levels are not accelerating.
Here’s what makes more sense to me. We had an acceleration in global warming in the 1980’s and 1990’s. Sea levels accelerated higher, as evidenced by the data that they want us to ignore in the mid/late 1990’s.
When global warming paused after the late 1990’s, the sea levels stopped accelerating higher.
What they appeared to have done was run a model with 40 variations(created and ensemble) and picked out the variations() that would explain the lack of sea levels accelerating………..for a different reason than the pause. In this case, a volcanic eruption in 1991.
This is not a heck of a lot different than climate model builders picking the equations to use in their models that represent what “they” think will give them the results. They believe that these are the best equations. Of course they do because those equations yield the right results when you plug in all the numbers.
You can tweek a model, change and plug in different equations until it has a solution that fits into your belief of how things went/should go. Their model doesn’t actually “know” the volcanic eruption caused this effect……….it was programmed in by the modelers, who played around with the equations until they got the right ones to show it!
So it’s not only worse than we thought, it’s also worse than it . . . is.
That sounds in my head like a Rocky line from a “Bullwinkle” cartoon.
“Pinatubo eruption masked sea level acceleration in satellite record”
That’s at about the same level as saying the horizon masks sea monsters like the Kraken from our consciousness, that infinity masks God/Satan/the Gods from our vision. When I was a kid the back fence masked a bogeyman called Jimmy Whiskers’ from me and all the other neighbourhood kids.
More from the Truth Room Audit Group at Climate Scientology central.
Satellite data are fudged to match models, see past refs to Soon.
Actual benchmarks show around 2 mm per year SLR globally, which has not changed since records began.
Photos of benchmarks from the 1880s show no changes.
The well documented Tasmanian benchmark located in a seismically stable area shows a few inches of sea level rise since the 1840s. See the Daly page.
Satellite data show SLR is acutally about 1 mm per year from 2005 to 2012, ref at
http://hockeyschtick.blogspot.com/2012/12/noaa-2012-report-finds-sea-levels.html
Anthony, this post — like so many others — has no conclusion. It just stops for a lunch break. What is your point? I live 1 meter above sea level, so I am interested in this information, not smarmy innuendo.
Is non-accelerating sea level supported by data from both wet gages and satellites?
Are there problems with the Pinatubo Eruption study we can discuss?
Has the search for missing ocean heat turned into the search for mission ocean volume?
The relative fluctuations in the rate of sea level rise appear to be a result of short-term fluctuations of ocean temperatures, particularly in the tropics, causing by thermal expansion and contraction, which is minimal at the shore line, overlaid on a general underlying rise due to a general warming of the overall system since the LIA, about the coldest period during this interglacial.
http://www.climate4you.com/images/SeaLevelSatellites-NEW.gif
Must have masked the tide guages in my country as well. They are still registering 1.7mm per year exactly as they have always done since recording began.
Dosn’t worry our local government though. They are trying to create “inundation zones” where every unfortunate property holder will effectively have a warning on his title. 18,000 of them in my city!
Inundations on 1.77mm a year?
Nah according to them its 10mm per year minimum,(1 meter by 2020). Our councillors read a lot of fiction it seems. Only trouble is there is no acceleration in sea level actually recorded yet.
rea my blog http://www.thedemiseofchristchurch.com
Cheers
Roger
[,(1 meter by 2020 = what in un-typo’ed units? .mod]
Are you saying that the sea level has risen by about 80mm since 1992? Not where I live
Still 1.77/yr here.
Cheers
Roger
Let me see if I understand this. Reality didn’t do what we want so we are going to build a computer model to behave the way we think reality would have happened if reality didn’t get in the way.
So look over here at this model that shows sea level rise did what it was supposed to.
CAGW warmunists realize the CAGW hypothesis is already dead.
They’re just laying the groundwork for creating “the-dog-ate-my-global-warming” excuses to explain why CAGW’s projections have failed so spectacularly, in an effort to buy just a little more time before this CAGW scam is laughed and ridiculed onto the trash heap of failed ideas.
There are typically 2~3 large volcanic events per century, and given the recent increase in global seismic activity, it’s only a matter of time before a large volcanic event occurs again.
When the next large volcano blows, CAGW zealots will waste no time blaming the volcanic event for CAGW’s huge disparities between projections vs. reality for virtually EVERYTHING: global warming, sea level rise, severe weather incidence, growing Antarctic land ice, recovering Arctic sea ice, flat ocean temp trends, etc…
The irony is that large volcanic events’ effects on climate are very short. Once volcanic particulates are removed by gravity/precipitation, the global climate quickly snaps back to pre-eruption levels within 2~3 years, which is further evidence of climate’s lack of sensitivity..
With all these various factors masking the effects of Man Made Global Warming (TM), how do they get the initial data to put into the computers to calculate the rate of Man Made Global Warming (TM)?
I’m still looking through the press release for anything describing an actual scientific study. It must be “hidden” somewhere in the satellite records they keep talking about.
Of course the usual suspects have quickly weighed in.
https://www.washingtonpost.com/news/energy-environment/wp/2016/08/10/seas-arent-just-rising-scientists-say-theyre-speeding-up/?hpid=hp_hp-more-top-stories_ee-searise-1000am%3Ahomepage%2Fstory&utm_term=.962f769e0f2e
Any paper that is based upon the output of models does not warrant serious consideration. That said:
How long did the effects of Pinatubo last? Was it 6 months, 1 year, 3 years, 5 years etc?
If one is concerned that Pinatubo has distorted the record, why not just look at the period say 1995 to date or 1996 to date or 1997 to date, and see what that suggests about sea level rise?
Has there been any acceleration in sea level rise these past 10 years, or past 15 years or past 20 years?
If there has been no such rise in acceleration over those periods, it is unlikely that a short term blip in the record, has any significant impact. This can be further put in context be checking against tide guage data that covers more than a century.
I agree with other commentators that the significant point that comes out of this paper is that they are admitting that there is no acceleration in sea level rise which runs contrary the AGW theory/conjecture, and the authors are seeking to come up with some explanation as to why that has not occurred/cannot be found in the observational data itself.
Nonsense, Pinatubo had no influence on sea level rise. The fact that they had to use computer simulations to extract the signal from noise is sufficient reason to ignore their data. Fact is, we do have excellent non-satellite sea level records covering eighty years that preceded the year 2008. The work was done by B. F. Chao, Y. H. Yu, and Y. S. Li, and was reported in the journal Science on April 11th, 2008. What these authors did was to correct all available sea level records for the effect of water held in storage by all confining reservoirs built since the year 1900. As a result, sea level records that had been irregular before these corrections were applied, became linear for the last 80 years of their project. I note that none of the satellite data take account of the effect of water held in reservoirs upon sea level rise. Chao, Yu and Li found that the slope of their corrected and linear segment of sea level rise could be determined to three significant figures and is 2.46 millimeters per year – just under 10 inches per century. A six millimeter change attributed by climate models to Pinatubo would stand out like a sore thumb in this environment. There was no such thing and there cannot be any aftermath to a non-existent perturbation of global sea level rise.