Is there anything global warming can’t do? Now it seems that there is so much global warming that it is slowing the rise of sea levels.
As glaciers melt due to climate change, the increasingly hot and parched Earth is absorbing some of that water inland, slowing sea level rise, NASA experts said Thursday.
Satellite measurements over the past decade show for the first time that the Earth’s continents have soaked up and stored an extra 3.2 trillion tons of water in soils, lakes and underground aquifers, the experts said in a study in the journal Science.
This has temporarily slowed the rate of sea level rise by about 20 percent, it said.
“We always assumed that people’s increased reliance on groundwater for irrigation and consumption was resulting in a net transfer of water from the land to the ocean,” said lead author J.T. Reager of NASA’s Jet Propulsion Laboratory. “What we didn’t realize until now is that over the past decade, changes in the global water cycle more than offset the losses that occurred from groundwater pumping, causing the land to act like a sponge — at least temporarily.”
The global water cycle involves the flow of moisture, from the evaporation over the oceans to the fall of precipitation, to runoff and rivers that lead back into the ocean. Just how much effect on sea level rise this kind of land storage would have has remained unknown until now because there are no land-based instruments that can measure such changes planet-wide.
The latest data came from a pair of NASA satellites launched in 2002 — known as the Gravity Recovery and Climate Experiment (GRACE). more here
Here is the Press release from the AMERICAN ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE
Land reservoirs helped offset sea level rise, study says
Recent increases in the storage of excess groundwater may be helping to offset sea level rise by as much as 15%, a new study finds. While the capacity of land to store water is known to be an important factor affecting sea level rise, the magnitude of its storage contributions are not fully understood. Land masses store water in numerous ways, though some human-induced changes — including to groundwater extraction, irrigation, impoundment in reservoirs, wetland drainage, and deforestation – are affecting this process, as are climate-driven changes in rainfall, evaporation, and runoff.
To gain more insights into how the land storage capacity may have changed over recent years, John Reager and colleagues analyzed satellite data from 2002 to 2014 that measure changes in gravity, and thus underlying changes in water storage. They combined this satellite data with estimates of mass loss of glaciers to determine what impact land water storage might have had on sea level change.
Their analysis suggests that during this timeframe, climate variability resulted in an increase of approximately 3,200 gigatons of water being stored in land. This gain partially offset water losses from ice sheets, glaciers, and groundwater pumping, slowing the rate of sea level rise by 0.71 ± 0.20 millimeters per year, the authors say. While a small portion of the increase in land water storage can be directly attributed to human activities – primarily, the filling of reservoirs – the authors note that climate is the key driver. The greatest changes in land water storage were associated with regional climate-driven variations in precipitation.
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Didn’t we miss a step somewhere? If the aquifers are recharging, doesn’t that mean that there is either more precipitation or that man has somehow cut his water use/reliance on groundwater pumping? Is there any evidence of ether of those being true?
Don K
February 12, 2016 at 6:27 am
“The vision here seems to be that of glacial ice shields sitting over dry sponge-like soils yearning to soak up the warm rains that will come when the ice melts. I’m no expert on Northern soils, but…”
Don, you are no expert, but you display more sense than what goes for experts these days. Yes (I am a geologist and engineer), under the glaciers, the soils and aquifers were full of water and yes they froze. Deep permafrost, over a km thick known in Siberia, took more than one glacial cycle to create and the cold of high latitudes maintained them – thawing and refreezing on top only a metre or so with the seasons. When the glacial period ice melted, there was also considerable water flow under the ice as you have today in Greenland and Antarctica. They drilled into a lake under the ice in West Antarctica that even has microbes living in it for millions of years:
http://www.nbcnews.com/science/science-news/its-alive-microbes-discovered-deep-beneath-antarctic-ice-n185386
Also, there is geothermal energy from within the earth rising up to the surface everywhere. Where it meets the ice sheets or the frozen soils, it establishes an equilibrium forming a wet interface between frozen above and liquid water below (and also, obviously hollows that are lakes). This is no future sink for water as the ice melts.
I believe they are referring to aquifers like sandstones, fractured granites and other porous formations on land that are used for human, animal and crop watering use. It is these that are filling up. Indeed, for such places as California, I’ve suggested before that special reservoirs should be created with wells down to aquifers and filtered by a layer of sorted sand and gravel. Water from wet periods and snow melt could be diverted into such manmade basins to more quickly recharge the main large aquifers. They would divert water at will when it otherwise would just flow to the sea and control water flow to also service downstream natural requirements. They also should conserve storm water in the main southern California cities into reservoirs for reuse. So simple to solve what have been agonizing problems for such a region.
Gary. We’re drifting off topic. But I lived much of my life in California and I’m reasonably familiar with the geology and the water problems. I suspect you have already guessed that the situation there is quite complex
Their problems include, but are not limited to …
1. Insane water rights laws (I think they may have made a start on tackling that)
2. Limited precipitation even in “normal years” Average annual rainfall at Bakersfield is about 15cm(6 in) If you can believe it Bakersfield is an agricultural center.
3. Overpumping the aquifers even in non-drought years.
4. The Western part of the state is a complex jumble of faults — many unmapped and is a highly active earthquake zone. Pumping water into the ground there will surely get you sued for every broken dish and cracked foundation in the next century
5. There’s literally no place to impound rainfall in much of urban Southern California on the rare occasions that it rains. They’ve channelized the rivers and built housing and shopping malls pretty much everywhere. To salvage the water, they’d have to pump huge amounts of water back upstream to a basin somwhere
I think they might actually tackle that mess and to their credit they really did do an outstanding job in the last century with an equally intractable air pollution problem. But it won’t be pretty. And the bitching …
“Also, there is geothermal energy from within the earth rising up to the surface everywhere.”
Shhhhhhh! Don’t tell them that! They’ll have to invent a race of humans that dwells under the crust of the Earth that is burning fossil fuels that are increasing the temperatures there…which is rising to the surface up here!! 🙂
This is an expansion of the specious arguments used to ‘explain’ the apparent decline in SLR in 2011 (GRL L19602 2012) and then the SLR slowdown from 2006-2011 (Cazenove NCC4: 358-361 2014). Both thoroughly debunked in essay PseudoPrecision.
Where this macrofails is that freshwater is 3% of the total, of which >2 is icecaps and < 1 is groundwater plus all surface water (e.g Great Lakes, Mississippi, Amazon,…). Land is 29% of the earths surface. To change SLR the land watertables have to change massively, and they haven't except where they are being drawn down (not up) by pumping, as at the worlds largest aquifer, the Ogallalla.
GRACE is an aging instrument that does not have this degree of precision, as shown elsewhere for Antarctic ice estimates (they got the isostatic adjustment wrong by a factor of 4, as Steve McIntyre recently showed).
Hi Rud
I am not sure what the article and paper are suggesting as I have indicated above in my comments. Hopefully someone can get past the paywall to see the entire assumptions and findings. At first, I thought they were saying SLR was below the CU 3.2mm/yr, now I just dont know.
I tried but will try harder.
Ceresco, a good enough solution. Go to the phys.org report on this Reager paper. http://Www.phys.org/2016-02-parched-earth-sea.html. They post a key map from Reager showing TWS anomaly inferred from GRACE. Two of the major plus water retention regions in the mapare the Amazon Basin and the Congo basin. That is hydrologicallu impossible. Details in essay PseudoPrecision concerning the Cazenove paper. So the GRACE data is somehow bad or misinterpreted. I have saved a copy of the map and may write up a guest post, recycling some of the stuff from the essay and send it to AW as a possible guest post.
Phys.org makes clear what Reager’s claim is. So does the Science abstract: global warming caused landfall precipitation that increased land groundwater retention by 3200+/-900 gigatons (a Gt is a cubic kilometer) from 2002 to 2014, slowing SLR over the period by 0.71 +/- 0.2 mm per year.
Implicitly attempting to explain why the AGW predicted accerleration in SLR did not happen.
Not worth pursuing further, or paying to get behind paywall.
catching up on my reading is all –
link has changed to
http://phys.org/news/2016-02-parched-earth-sea.html
I hope, in the paper, that they validated their claim of ‘associated with climate-driven variability in precipitation’ by matching the changes in precipitation with the supposed amount of additional groundwater stored.
Yeah, right …
Your suspicion is correct. They did not, and that failure is going to be a great embarassment to NASA and JPL. Illustrated post already off to AW. Next to last sentence invokes your thought about ground truthing. Thanks and h/t.
Its a really big, obvious goof. WUWT readers are in for a good chuckle, as I suspect AW will post it. It deserves to be a Friday funny, its that bad a goof.
All GRACE does is measure the earth’s gravitational field on a global scale. They can make estimates of the mass of water being moved around and showing up as local changes, but I haven’t seen any sign that they can measure sea level directly, especially with sub-millimetre precision. Can they detect changes in the total mass of water in the oceans? A brief browse of their website does not show that they make that claim. Rather, they see local changes on land that they attribute to water loss/gain. They seem, in this article, to be using the net sum of all those local changes to determine a value for the rate of SLR. Or is it the other way round? Can’t tell from the abstract.
But, and this is a big but. Having hung around WUWT for a while now, I have the distinct impression that most of the measured SLR is due to thermal expansion as the oceans warm very gradually (probably still recovering from the last glacial period?). That component of SLR is not going to change the mass of the oceans, so I suggest that it’s probably invisible to their gravity-measuring system.
So I’m not sure I can really believe any of it.
That said, knowing the large-scale variation of the earth’s gravitational field is an important contribution to earth science. If their data can be integrated over time to produce really precise gravity maps, who knows what discoveries could come from it.
GRACE is supposed to be able to detect ground water variation from land mass gravity)change. The SLR impact is only a computational inference therefrom. One gigaton of water (a cubic kilometer) changes the sea level by 2.78 microns (calculation in essay PseudoPrecision). This is the second time NASA has tried to use GRACE to explain some SLR ‘anomaly’ (meaning not doing what warmunists said), and it is their second massive fail. An illustrated possible guest post was just sent to AW. Enough to demand a Science retraction. But I won’t bother after Science brushed off a worse case I provided to them (proven academic misconduct in the Marcott hockey stick paper back in 2013, essay A High Stick Foul).
“A theory that explains everything, explains nothing.” –Karl Popper
For many years now alarmist articles have appeared in the general press about the over- extraction of water from vitally important aquifers in the US and Australia , imperiling local agriculture, and from below Venice , risking total submergence of that city .
Now it seems that global warming is righting that wrong. Do we fully appreciate the blessings of AGW: the cold places are made warm , the deserts are made green and the higher CO2 produces bumper harvests
Global Warming is really an insidious menace, isn’t it? Apparently consciously conspiring to hide itself for two decades – stalking at the bottom of the ocean, camouflaging it’s presence by masking the sea-level rise, lurking always unseen… until it’s TOO LATE!
Boy, I gotta stop – I’m scaring myself.
Is this a good time to ask for the Climate Trial verdicts to be overturned and for all skeptical scientists to be released from the Climate Prison System?
Greening of earth might suck up some water in a circular matter -evaporation.
NASA is no longer an agency for research of scientific reality. Small wonder we no longer have a real space program. By order of the Great Deceiver! …pg
It was recently published (here?) ,that we have knocked down 500+ dams in the last decade, more than the number in all the years since the founding of the republic combined. All that reservoir water should have raised the sea level by an amount that would be measureable by these “instruments”.
So how much faux sea level rise is attributable to these fool Greens doing this?
So, in addition to global warming causing global cooling, global warming also impedes sea level rise. Anyone out there recognize “negative feedback” when they see it?
Seems to me that soils retain more moisture when they are cooler, not warmer and that would suggest global cooling.
I should have said “a reduction in the increase in global warming”, not global cooling in order to be consistent with the political class.
No I’m sorry but you can’t even say that. Everything must forever accelerate towards ‘worse-than-we-thought’ at all times. An admission that any aspect of CAGW was slackening off in any way would be catastrophic as no one would listen anymore. I mean, no one actually is listening anymore but they just don’t seem to have noticed that yet.
And that of course is the real beauty of the whole scheme because everyone can sit back and watch as the claims get wilder and shriller and more and more contorted in their epicyclic gyrations. The natural endgame to this is either to go for the full-on biblical fludde arguments and things of that kind or don loincloth, cast a few chicken bones around and hiss and screech at the wind. They seem to be favouring the latter approach at the moment but either way it’s comedy gold.
Most of 6″/ century Sea Level Rise has been from ocean thermal expansion.
NASA announced last year that Antarctic land ice has been increasing at 100 billion tons per year since ICE-SAT data came online in 1992, so it’s obvious alarmists doom and gloom predictions are absurd and unfounded.
NASA must keep fabricating excuses for their failed predictions to keep the grant gravy train chugging along until it finally just runs off the rails..
There is a very positive aspect to all this hysteria – it motivates us that delight in truth to think and discuss. Give them some credit 🙂
It’s hard for me to envision there being enough ice in the world that, if melted and spread over the entire globe, would make more than a modest increase in sea levels.
Does anyone know how much water is in the form of ice on earth? What is the surface area of the oceans? If all that ice melted, how deep would that be if spread out over the current surface of oceans?
What truly is the worst case scenario (all the ice melting)?
katherine009,
This may answer some of your questions:
http://www.johnstonsarchive.net/environment/waterworld.html
Thanks, db! Exactly what I wanted to know. I found it interesting that the area I live (Great Lakes) appears relatively unchanged. Phew!
“To gain more insights into how the land storage capacity may have changed over recent years, John Reager and colleagues analyzed satellite data from 2002 to 2014 that MEASURE CHANGES IN GRAVITY”
Silly me, I would have measured groundwater by……wait for it…measuring the groundwater.
No wonder I’m too dumb to work in the public sector.
Much like all the poor excuses for the ‘pause’, this is just a poor excuse for why sea level rise has not increased.
Are they saying that before this paper, models did not take into account precipitation uptake in soil or aquifers?
I had read this on Yahoo News last night. They had this:
“These results will lead to a refinement of global sea level budgets, such as those presented in the Intergovernmental Panel on Climate Change (IPCC) reports, which acknowledge the importance of climate-driven changes in hydrology, but have been unable to include any reliable estimate of their contribution to sea level changes,” said senior author Jay Famiglietti, a professor at the University of California, Irvine.
“But we’ll need a much longer data record to fully understand the underlying cause of the patterns and whether they will persist.”
Meaning they need more money to study this for a loooong time?
> Meaning they need more money to study this for a loooong time?
At least ’til retirement.
This article reports that over then last decade 3.2 trillion tons of water has been added to aquifers, lakes and soils.
3.2 trillion tons of water
= 3200 GT
/ 1.1023 Gt/GT
= 2903 Gt
/ 362 Gt/mm-SLR
= 8 mm of SLR over ten years
That’s the equivalent of 0.8 mm/year of sea-level rise, a rate of just over 3” per century.
But the article states that that represents a 20% reduction in the rate of sea-level rise, which is too low. It would imply that measured sea-level rise averages 3.2 mm/year, which is way too high.
The actual, measured rate of sea-level rise, averaged over the best long-term coastal tide gauges, is just under 1.5 mm/yr.
0.8 / (1.5 + 0.8)= 35%, not 20%.
It appears that the authors are referencing their calculations to satellite altimetry measurements of sea-level, rather than coastal sea-level measured by tide gauges. That is a mistake.
Most fundamentally, satellite altimeters measure the wrong thing. Their measurements are distorted by “sea-level rise” caused by thermal expansion when the upper layer of the ocean warms. But that is a strictly local effect, that doesn’t affect the quantity of water in the oceans (and is of little consequence to the coasts), and doesn’t affect sea-level elsewhere (e.g., at the coasts). So it shouldn’t be compared to the amount of water removed from the oceans and stored in aquifers and lakes.
Also, that sea-level rise only matters at the coasts, but satellite altimeters are incapable of measuring sea-level at the coasts. Tide gauges measure sea-level at the coasts, where it matters.
Also, tide gauge measurements of sea-level are much higher quality than satellite altimetry measurements. The satellite measurements of sea-level are of questionable reliability, and vary considerably from one satellite to another. Also, some of the tide-gauge records of sea-level measurements are nearly ten times as long as the combined satellite measurement record, and twenty times as long as any single satellite measurement record.
Prof. Peltier estimates that meltwater load from the melting of the great ice sheets (~10k years ago) is causing the ocean floors to sink by enough to cause a 0.3 mm/yr fall in sea-level, absent other factors. For water mass budget calculations like this study’s, it is reasonable to add that number (0.3 mm/yr) to measured rates of sea-level, even though the resulting sum is not truly sea-level, and is not useful for projecting sea-level for coastal planning. (It’s an attempt to calculate what the rate of sea-level rise would be, were it not for the hypothesized sinking of the ocean floor.) But 1.5 mm/yr + 0.3 mm/yr is still just 1.8 mm/yr, and 0.8 mm/yr would represent a 31% reduction (from 1.8 + 0.8 = 2.6), not just 20%.
NOAA has done linear regression analysis on sea-level measurements (relative sea-level) from 225 long term tide gauges around the world, which have data spanning at least 50 years. (Note: the literature indicates that at least 50-60 years of data are required to determine a robust long term sea-level trend from a tide gauge record.)
It is important to realize that there’s been no sign of any acceleration (increase in rate) in most of those tide-gauge records, in over three-quarters of a century.
The rate of measured sea-level rise (SLR) varies from -17.59 mm/yr at Skagway, Alaska, to +9.39 mm/yr at Kushiro, Japan. 197 of 225 stations (87.6%) have recorded less than 3.3 mm/yr sea-level rise. At 47 of 225 stations (20.9%) sea level is falling, rather than rising. Just 28 of 225 stations (12.4%) have recorded more than 3.3 mm/yr sea-level rise. The average SLR at those 225 gauges is +0.90 mm/yr. The median is +1.41 mm/yr.
That’s probably slightly less than the true global average, because a disproportionate number of those 225 stations are northern hemisphere stations affected by PRG (i.e., the land is rising). OTOH, quite a few long-term tide gauges are substantially affected by subsidence (i.e., the land is sinking), often due to extraction of water, oil, or natural gas, or due to the location having been elevated with fill dirt which is compacting (like Galveston).
I downloaded the two sea-level measurement spreadsheet files (U.S. and global) from NOAA’s page, and combined them into a single Excel spreadsheet. For ease of sorting, I changed the U.S. station ID numbers by adding an “A-” prefix (“A” for “American”). I also added “average” and “median” lines at the end of the spreadsheet. The average of all 375 NOAA-analyzed stations is 1.28 mm/yr, and the median is 1.71 mm/yr:
http://www.sealevel.info/NOAA_AllStationsLinearSeaLevelTrends_2015-08.xls or
http://www.sealevel.info/NOAA_AllStationsLinearSeaLevelTrends_2015-08.htm
NOAA says that the average is 1.7-1.8 mm/yr. Some of the difference between the calculated average and NOAA’s figure for MSL rise may be due to the addition of model-derived GIA adjustments to the measured rates when calculating the average, to attempt to account for Post-Glacial Rebound (PGR). My guess is that they’re using Prof. Richard Peltier’s figures. (Unfortunately, those figures are only very loosely correlated with what is actually happening at the tide-gauge locations.)
Unfortunately, many of the tide station records in NOAA’s expanded list of 375 are too short to be appropriate for measuring sea-level trends. The literature indicates that at least 50-60 years of data are needed to establish a robust sea-level trend from a tide station record. But the shortest record in NOAA’s list is Apra Harbor, Guam, with just 21 years of data. (The text at the top of NOAA’s page says, “Trends with the widest confidence intervals are based on only 30-40 years of data,” but that is incorrect. I suspect they wrote it before they added the gauges with very short records.)
So I also made a version of this spreadsheet in which stations with records shorter than 50 years are omitted.
Considering only tide stations with records of at least 50 years, the average and median rates of MSL rise (of the 225 remaining stations) are 0.90 mm/yr and 1.41 mm/yr, respectively:
http://sealevel.info/NOAA_AllStationsLinearSeaLevelTrends_2015-08_50yr.xls or
http://sealevel.info/NOAA_AllStationsLinearSeaLevelTrends_2015-08_50yr.htm
(I also tried limiting it to stations with records of at least 60 years, with very similar results: average 0.77 mm/yr, and median 1.37 mm/yr.)
The average (0.90 mm/yr) is probably unrealistically low, due to the disproportionate number of stations in northern Europe which see low or negative rates of measured sea-level rise due to PGR. The fact that the average is less than the median also suggests that there are a disproportionate number of low-end outliers.
I also tried another approach, in which I excluded the most extreme latitudes. I started with just the “50+ year” stations, and included only stations within a latitude range of 45 (i.e., I excluded stations above 45 north or below 45 south). The resulting average and median for 137 stations were 2.22 mm/y and 2.02 mm/yr, respectively:
http://www.sealevel.info/NOAA_AllStationsLinearSeaLevelTrends_2015-08_50yr_lowLat.xls or
http://www.sealevel.info/NOAA_AllStationsLinearSeaLevelTrends_2015-08_50yr_lowLat.htm
That approach largely solves the problem of low-side bias introduced by stations which are affected by PGR (which lowers the calculated average), but it doesn’t solve the problem of high-side bias introduced by stations affected by subsidence (which raises the calculated average). So the average (2.22 mm/yr) is probably unrealistically high. The fact that the average is greater than the median also suggests that there are a disproportionate number of high-end outliers.
So I tried another approach, this time explicitly eliminating “outliers.” I started with just the “50+ year” stations, but excluded the 40 stations with the lowest rate of sea-level rise (including most of those experiencing falling sea-level), and the 30 stations with the highest rate of sea-level rise (including most of those experiencing severe land subsidence, like Galveston, which is built on sinking fill dirt). The resulting average and median rates of sea-level rise (calculated from 155 stations) are both 1.48 mm/yr:
http://www.sealevel.info/NOAA_AllStationsLinearSeaLevelTrends_2015-08_50yr_less_high30_and_low40.xls or
http://www.sealevel.info/NOAA_AllStationsLinearSeaLevelTrends_2015-08_50yr_less_high30_and_low40.htm
That figure, 1.48 mm/yr, is my current best estimate of globally averaged coastal sea-level rise. At first glance, excluding more low outliers than high outliers might seem to bias the result to the high end. But I think it is justifiable, because of the disproportionate number of northern European and North American stations at locations where the land is rising due to PGR. The fact that the median and average are equal suggests that there aren’t disproportionate numbers of either high or low outliers. (I also tried excluding the low and high 35 stations, and the result was an average MSL rise of 1.36 mm/yr, and median 1.41 mm/yr, which suggests that it includes more low outliers than high outliers.)
Note that 1.48 mm/yr is less than six inches per century.
Note, too, that if you add Peltier’s +0.3 mm/yr GIA to that calculated 1.48 mm/yr global average rate of MSL rise, the sum is within NOAA’s 1.7-1.8 mm/yr range.
It is not possible to torture the tide-gauge data into yielding a globally averaged rate of sea-level rise anywhere near 3.2 mm/yr.
I stumbled on this yesterday from Robert Scribbler. He’s claiming 5 mm/year since 2009?
http://robertscribbler.com/2016/02/04/rapid-acceleration-in-sea-level-rise-from-2009-through-october-2015-global-oceans-have-risen-by-5-millimeters-per-year/
I haven’t had time to fully digest it and, I’m not being lazy, but I’d like people that obviously know more about this than I, to comment.
Scribber is just wrong. Geostationary tide gauges or land motion corrected by differential GPS show no such thing. Nor does satellite altimetry. That rate is certainly possible locally with subsidence or river delta compaction. Both are at work, for example, in Bangkok.
Excellent post, I’ve tried to duplicate the 3.2 mm/yr finding that we usually read about just like you did, and I come up short as well. Plus as you know Colorado University has adjusted (including GIA) 0.9 mm/yr extra into their data base over the last ten years or so.
Yes, Steve, and I have a link on my site to your very informative notes and graph, here:
http://www.sealevel.info/resources.html#colorado
“It appears that the authors are referencing their calculations to satellite altimetry measurements of sea-level, rather than coastal sea-level measured by tide gauges. That is a mistake.”
Not from a public relations angle, it isn’t. You’re going to argue with scientists who shoot satellites into space? Ha. Try putting one of your coastal gauges on a poster and see how many copies teenagers hang on their bedroom walls.
I highly doubt that very many teens put posters of satellites on their walls. Or even rockets now that NASA has become a weather agency instead of a space one. 🙂
It was a real pleasure for me to encounter your post here, Dave Burton.
I was not previously aware of your website sealevel.info
This is not my area, but here is what I have learned so far.
It seems that very few people will ever have any grasp of the problems inherent in generating truthful or even realistic GIAs.
This topic seems to immediately carry us into an epistemological wormhole.
As with ice loss calculations reliant purely on GIA – we do not know two things.
We do not know 1. how much sea level rise or ice loss has occurred.
And 2. we do not know how much GIA is occurring at various locations.
There are lots of other things which are not known, such as the amount of water loss from aquifers or ground subsidence etc etc.
But focusing on those first two unknowns – when we generate a guess for GIA then this allows us to create a corresponding value for SLR. Since the first is an informed guess then the second can also not be better than an informed guess.
People widely do not seem to grasp that figures for SLR purportedly “measured” by GRACE are in fact primarily generated by the speculative assessment of GIA.
And that where there is an opportunity to empirically test proposed GIA figures (by using fixed GPS) then they are often found to be way off from reality.
Sadly, I suppose that we should expect the guessing game to continue for many profitable years to come.
This would not be a significant issue for anyone were it not for the concealment of the true nature of the output of the GIA/SLR/ice loss/GRACE guessing game – and the fact that the guesses thus produced are being used to guide real-world policy and potentially lead to astonishingly poorly judged public policy decisions.
“We always assumed that people’s increased reliance on groundwater for irrigation and consumption was resulting in a net transfer of water from the land to the ocean,”
It’s good to know that all of those aquifers that were being drawn down and depleted were just an assumption or a figment of the imagination. Thank you gravity satellites! Let the artesian wells spring forth again!
How come gravity satellites good, but temperature satellites bad?
You mean to tell me that the earth has restorative mechanisms that repel it from tipping points? Now that’s novel. I wonder if that might just be somehow related to the observation that organized life has been here for hundreds of millions of years? Maybe?
There is in fact NOTHING warming can’t do. No matter what the observation from drought to floods to freezing cold it’s all WARMING BABY!!!!
A negative feedback mechanism? How non-canonical!
Even if they are right in assessing “gravitational gain” to be entirely water capture on land they are still saying that this accounts for less than a millimeter of the observed change. So still not above the sole of the penny loafers. WUWT