Reposted from Roy Spencer’s Blog
July 21st, 2017 by Roy W. Spencer, Ph. D.
If I had not looked past the headline of the press report on a new study, I would have just filed it under “It’s worse than we thought”. A new study in Nature reported on July 17 carried the following headlines:
“Satellite snafu masked true sea-level rise for decades”
“Revised tallies confirm that the rate of sea-level rise is accelerating as the Earth warms and ice sheets thaw.”
When I read that, I (like everyone else) assumed that corrections to the satellite sea level data since 1993 have now led to a revised trend toward faster (not slower) sea level rise. Right?
Wrong.
During the satellite era (since 1993), the trend in sea level rise was revised downward, by almost 10%, from 3.28 mm/year to about 3.0 mm/year. (For those concerned about Miami going underwater, these numbers equate to a little more than one inch every 10 years). This result was published back in April in Geophysical Research Letters, and the new Nature study looks at the wiggles in the revised data since 1993 and makes ominous pronouncements about sea level rise “acceleration”.
I’m calling “fake science news” on the Nature reporter who covered the story. The headline was technically correct…but misleading. (I can also make up technically correct headlines: “Scientists Agree: Sea Levels are Rising, We are All Going to Die”)
The researchers in April made a major adjustment to the first 1/4 of the satellite record, bringing those early sea levels up. This results in adding curvature to the upward trend (an acceleration) by flattening out the early part of the curve. This new signature of “acceleration” was what made the news in the new Nature study, even though the long term trend went down.
Should this New “Acceleration” be the News?
In a word, no.
Short-term undulations in the sea level rise curve should not be used as a predictive curve for the future. They are affected by a wide variety of natural phenomena. For example, ice loss from Greenland (which was large in 2011-12) has recently reversed itself with huge gains made in the last year. These events are governed by natural variations in weather patterns, which have always occurred.
For longer-term variations, yes, the rate of sea level rise during the entire period since 1993 probably is a little more than, say, during the period since 1900 (sea level rise was occurring naturally, anyway). But the inferred acceleration is small. And even that acceleration could be mostly natural — we simply don’t know.
My main point is that the Nature headline was misleading. They clearly had to find something in the study that supported the alarmist view of sea level rise, and they figured few people would read past the headline.
A face-value reading of the two main studies together results in the conclusion that sea level rise since 1993 has been revised downward. The most recent study then reads too much into the wiggles in the new data, and even implies the acceleration will continue with the statement, “The suggested acceleration… highlights the importance and urgency of mitigating climate change and formulating coastal adaptation plans to mitigate the impacts of ongoing sea level rise”.
The new study does NOT revise recent sea level rise upward, as is suggested by the Nature headline quoted above.
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Falling sea levels should be more of a concern, because if that happens, it could signal a return to another glacial period. It also means more shoreline to build on, and create alarm about, when sea levels fluctuate up again.
We never learn.
I’m surprised sea level rise isn’t measured in angstroms.
There is an easy conversion between millimeters and angstroms! 🙂
I wonder how the bet on travelling from Svaalbard to the N Pole without seeing ice is looking?
Well, the “SEE” level on this nature article has certainly risen!
(don’t say “si”, say “oui”)…
Much like the “collusion” delusion, the “Day after Tomorrow” scenarios of sea-level rise are a figment of uninformed imagination. Nevertheless, the evident accelerations and decelerations of that rise do provide scientifically useful indications of the strength of some factors involved. Noteworthy in this connection are the strong local minima of rate shown in Greg’s graph here in the 1860s, 1920s and 1980s. Bearing in mind the steric component, these prominent features roughly 60-odd years apart suggest that multidecadal global temperature swings were considerably stronger than most published GAST indices indicate. In any event, the recent acceleration to ~3mm/yr. evident primarily in satellite data cannot be attributed credibly to the monotonically rising CO2 concentrations.
Yeah, Sky, one has to wonder if the rate of sea level rise is an indicator that the temperature data sets might be way off. They used to look more or less like what is seen in Greg’s graph. Plus, there is the c*nsp*r*cy theory out there that Callender sought to manipulate the station data to produce results more in line with his failing agw theory. (he sought a .75C/ Century increase through various techniques of manipulating temperature stations) i think that you’re right that the SLR data brings up a question or two that need answers…
http://oi44.tinypic.com/29axhua.jpg
And the same is true of extreme weather metrics. Floods, cyclones, droughts, etc
Or even the remarkably non-alarming precipitation trends.
All that anyone has, is some arctic warming, which can be accounted for as PDO warm cycle plus emergence from the little ice age.
Maybe Antartica really is gaining mass – as shown by NASA Zwally.
Maybe the ARGO floats really did reveal that the oceans were cooling – before all the inconveniently cooling floats were hand-cherry-picked, declared to be faulty and removed from the analysis.
Maybe, what the science is really telling us – is that the original CRU analysis of global temperatures from 1850 was bunk.
I’m inclined to be most suspicious of the ocean component during the first century of the series.
We have been warping everything else to fit with those original analyses of the temperature of ocean water collected by sailors using a variety of types of bucket.
And yet – it simply isn’t stacking up.
Maybe those evaluations of the ocean bucket temperatures – plus infilling and homogenization of nearly entire continents during pre-1950 period – maybe the entire thing is bunk.
If it isn’t then why is the rest of the story not conforming to expectation?
I’m not all that surprised that buckets on ropes may not be able to tell us much about the precise average temperature of the globe.
Nobody should be surprised – on the face of it, it sounds idiotic.
afonzarelli:
Results quit similar to the graph you show are obtained–without resort to any trend correction–simply by relying exclusively upon vetted, century-long station records that show high low-frequency coherence with their neighbors. Because these are land records, the decline to the 1976 low that preceded the present warming swing registers even more strongly than in the trend-adjusted HADCRUT4 global average.
indefatigablefrog:
The fundamental problem with historical SST data is not the use of various buckets for acquisition, but the very sparse, highly irregular sampling outside well-traveled sea lanes. This raises serious frequency-aliasing issues in cosntructiing SST time-series that have never been satisfactorily addressed in “climate science.” The transition to engine-intake temperature measurements during WWII introduces yet another confounding factor. The upshot is that we have only an uncertain, partial glimpse of global SST variations before the advent of satellites.
Oops, that should be 1850s.
Funny thing about science… it ain’t never settled
Can someone explain (beyond the Trump effect) why there are no more updates to the NOAA/NESDIS/STAR downloadable datasets. The URL I am looking at is
https://www.star.nesdis.noaa.gov/sod/lsa/SeaLevelRise/LSA_SLR_timeseries_global.php
It is titled:
Laboratory for Satellite Altimetry / Sea Level Rise
Global sea level time series
The last dates are 2016.7032, mid September 2016.
Shaking my head at a comment made by Steven Mosher that taking a look at “other data” surrounding Tokyo shows that Tokyo’s past readings were “too high”. WTF does that mean?
If the other data shows Tokyo’s temperature used to be ten degrees higher than the surroundings, and current shows it to be 5 degrees higher than the surroundings, then it’s obvious to anyone with a brain that the surrounding areas are likely now entering into the same urban heat island that biased Tokyo’s readings in the past, which is useless for gauging the accuracy of any of Tokyo readings, past, present or future.
If the other data shows Tokyo’s temperature used to be five degrees hotter than the surrounding areas, and now it’s ten, then Occam’s Razor suggests the urban heat island or some other similar effect is becoming more pronounced in Tokyo than in the surrounding areas, which if anything would indicate all of today’s Tokyo readings should be adjusted downward, and the past left alone.
There is no mathematically or scientifically justifiable reason to adjust past data based on current data. There are far too many building and hardscape density/profile and micro-climate shifts possible to determine exactly why today’s temperature patterns differ from those in decades past.