A recently published paper appearing in the PNAS authored by et al reveals that calculations of water storage in many river basins from commonly used global computer models differ markedly from storage estimates from GRACE satellites.
Source: PNAS, et al
Because we increasingly rely on models to project the impacts of humans and climate on water resources, it’s crucial we know how reliable these models really are.
In total the authors evaluated model reliability based on a comparison of decadal trends (2002–2014) in land water storage from seven global models (WGHM, PCR-GLOBWB, GLDAS NOAH, MOSAIC, VIC, CLM, and CLSM) to trends from three Gravity Recovery and Climate Experiment (GRACE) satellite solutions in 186 river basins, representing roughly 60% of global land area.
The GRACE satellites are operated by NASA and the German Aerospace Center and measure changes in the force of gravity across the Earth, which is influenced by changes in the water storage in an area.
They found that the models underestimate the large decadal (2002–2014) trends in water storage relative to GRACE satellites. The authors summarized: “The poor agreement between models and GRACE underscores the challenges remaining for global models to capture human or climate impacts on global water storage trends.”
In summary, the model results calculated a decline in global water storage during the study period, but GRACE data showed an increase!
For example, in the Amazon, GRACE estimates a large increasing trend of ∼43 km3/y, whereas most models estimate decreasing trends (−71 to 11 km3/y). Land water storage trends, summed over all basins, are positive for GRACE (∼71–82 km3/y) but negative for models (−450 to −12 km3/y), contributing opposing trends to global mean sea level change. Impacts of climate forcing on decadal land water storage trends exceed those of modeled human intervention by about a factor of 2.
As the authors note, policymakers and planning experts increasingly rely on models for impacts of humans and climate on water resources, so their accuracy is important. But the paper study shows that relying on the models would be totally unwise and would lead to totally bad decision making.
It’s time for policymakers to realize that climate models of any type cannot be used to prepare for the future.
But GRACE data can be relied on? Are you guys finally trusting the data? Or will you continue to claim that Antarctica is increasing in ice mass, as some scientists modeled it?
Or is this a typical skeptic’s thing. Cherry picking what you like and supporting it no matter if you don’t support the data in other cases? 😉
East Antarctica (3/4ths of the continent), where it’s been rapidly cooling since 1979 (Clem et al., 2018, has been increasing in ice mass. The Southern Ocean has been cooling since 1979. Sea ice in the Southern Hemisphere as a whole has been expanding since 1979. The Antarctic Peninsula has been rapidly cooling (-0.47°C per decade) since 1999. It’s only in the portions of West Antarctica where there is high geothermal heat flux that the ice sheet has been melting…from below.
Iverson et al., 2017
https://www.nature.com/articles/s41598-017-11515-3
“The first physical evidence of subglacial volcanism under the West Antarctic Ice Sheet … New evidence from ice core tephra shows that subglacial volcanism can breach the surface of the ice sheet and may pose a great threat to WAIS stability. … The sources of these tephra layers were likely to be nearby subglacial volcanoes, Mt. Resnik, Mt. Thiel, and/or Mt. Casertz.”
—
https://www.sciencedaily.com/releases/2017/08/170814092735.htm
“West Antarctica’s vast ice sheet conceals what may be the largest volcanic region on earth, research has revealed. … Previous studies and the concentration of volcanoes found in the region together suggest that activity may have occurred in previous warmer periods.”
—
Seroussi et al., 2017
http://onlinelibrary.wiley.com/doi/10.1002/2017JB014423/abstract
“Mantle plumes may more than double the geothermal heat flux above nominal continental values. … The experiments show that mantle plumes have an important local impact on the ice sheet, with basal melting rates reaching several centimeters per year directly above the hotspot.”
But please do explain why it is nonetheless your belief that human CO2 emissions are driving the trends in Antarctica.
Well at least a small part of the models’ predictions came true [the part I’ve put in bold].
According to satellite rainfall estimates, the highest weekly accumulations (>100mm) were registered over the parts of southern Senegal, Guinea, southern Mali and Sierra Leone.
Across the Gulf of Guinea countries, since June, the quantity and distribution of seasonal rainfall is expected to benefit several cropping and pastoral areas of West Africa. Analysis of rainfall anomalies suggests there has been improvement in areas that were previously experiencing anomalous mid-season dryness. Senegal and Sierra Leone, the heavy rains has mitigate moisture deficits returning conditions closer to normal.
Portions of eastern Sudan and western Ethiopia have continued to experience above-average seasonal rainfall. However drought conditions continue to threaten over parts of Ethiopia, South Sudan, Uganda and DRC.
Info from —
http://www.cpc.ncep.noaa.gov/products/international/africa/africa_hazard.pdf
Kenneth, Pierre is regularly writing that Antarctica would be gaining ice mass. Why not stay on topic and discuss why he does this despite trusting GRACE data in other instances.
Please explain where in my short comment I expressed this “belief”?
If you are referring to previous comments of mine, I quoted you the relevant part of your quote (Clem at al, 2018) … didn’t I? The “warmth” down in Antarctica comes from ocean currents.
The increased OHC that is caused by the higher CO2 concentration gets distributed by ocean currents.
“The “warmth” down in Antarctica comes from ocean currents.”
Oh, so its absolutely NOTHING to do with human activity
Or are you fantasising that humans cause warmer ocean currents (even though the southern oceans have been cooling for the last decade or more)
Funny those currents ONLY heat the region that has volcanoes under it, isn’t it seb.
Must be a very “clever” currents.
They also “sneak” under the sea ice to melt the coastal ice… very sneaky 😉
They even form pools warm enough to bathe in, near the end of the peninsula, did you know that?
MUST BE MAGIC. !!
*sigh* spikey, so have those volcanoes suddenly (since the 1980s) increased their output in the W/m² range? Is that what happened down there? They are also warming the ocean? Wow!
Funny … you don’t trust actual scientists when they write that? How hardened is your core belief that the world is like you think it should be? This is just wow!
Poor seb, has to go deep into fairy-tale land to imagine volcanoes are cold and ocean warming of 0.08ºC melts Antarctic ice,
But ONLY where those cold volcanoes are.
WOW.. just WOW.
whatever meds they have you one, keep going.
Its hilarious. !!
Have you found any answers to those two questions yet, seb??
Do you need reminding of them.??
Q1. In what way has the climate changed in the last 40 years, that can be scientifically attributable to human CO2 ?
Q2. Do you have ANY EMPIRICAL EVIDENCE at all that humans have changed the global climate in ANYWAY WHATSOEVER?
“so have those volcanoes suddenly (since the 1980s) increased their output in the 1990s”
Again with AWAREMESS
Yes seb, there was a global shift in seismic activity just before the 1998 El Nino
https://www.omicsonline.org/articles-images/earth-science-climatic-change-Frequencies-7-344-g005.png
Its amazing how IGNORANT you CHOOSE to remain!
And how totally FREE OF EVIDENCE you are for CO2 warming.
Yeah, really amazing how you post a single image that explains it all 😉
I hope you are not implying now that seismic activity had anything to do with the 1998 El Nino …
Here is the paper you lifted that image from, in case you wanted to actually present a source for your claim that correlation means causalisation:
https://www.omicsonline.org/open-access/the-correlation-of-seismic-activity-and-recent-global-warming-2157-7617-1000345.php?aid=72728
Poor seb, DENYING data that clearly shows a large increase in seismic activity.
DENIAL of REALITY is your only faceplant nowadays, isn’t it seb
Only a total and utter scientific idiot would think that 0.08ºC change in ocean temperatures can melt glaciers, and then say that volcanoes directly under the ice have no effect.
That is seb for the world to see.
https://www.express.co.uk/news/science/979895/Volcano-eruption-climate-change-antarctica-melting-ice-caps-Pine-Island-Glacier
https://www.independent.co.uk/environment/volcano-antarctic-ice-melting-pine-island-glacier-sea-level-climate-change-global-warming-a8423131.html
https://www.sciencealert.com/pine-island-glacier-antarctica-has-hidden-volcano-heat-underneath
https://today.uri.edu/news/researchers-discover-volcanic-heat-source-under-major-antarctic-glacier/
https://www.exopolitics.org/scientists-confirm-volcanoes-melting-antarcticas-ice-sheets/
http://www.foxnews.com/science/2018/06/27/antarcticas-big-secret-active-volcanic-heat-found-under-pine-island-glacier.html
https://www.livescience.com/62924-volcanic-heat-under-antarctica-glacier.html
https://www.scitecheuropa.eu/volcanic-heat-source-antarctic-glacier/87652/
FACE FACTS, and WAKE UP FROM YOUR DENIAL, seb
http://blogs.discovermagazine.com/d-brief/2017/08/14/volcanoes-under-antarctica/#.W2BbB-R–cw
100 NEW volcanoes found under the Antarctic.
Seismic activity increasing world wide.
New ACTIVE volcanoes found under the fastest melting glaciers
.. and this mindless headless chook thinks the West Antarctic is melting from a 0.08ºC ocean temperature rise.
SAY WHAT ? !!!!!!!!
Some bizarre new form of hallucinogenic.. or
.. brain-hosing so deep that there are not even two synapses left to rub together.. MUST be suspected. !!
“The increased OHC that is caused by the higher CO2 concentration gets distributed by ocean currents.”
What a load of anti-science, unsupportable BS. !!
OHC has risen global by only 0.08ºC (0-200m) since the 1950s, same with the southern oceans
You would have to be a blathering idiot to think 0.08ºC is causing the volcanic ice melt in the West Antarctic.
There is ZERO evidence of CO2 warming oceans, anywhere anytime. And you KNOW that.
Still waiting…
Q1. In what way has the climate changed in the last 40 years, that can be scientifically attributable to human CO2 ?
Q2. Do you have ANY EMPIRICAL EVIDENCE at all that humans have changed the global climate in ANYWAY WHATSOEVER?
Feel free to calculate your volcanic activities (the increase) into the same forcing units as the OHC increase. Let’s see what magnitude differences we are talking about 😉
Feel free to remain IGNORANT that volcanoes are HOT.
And that water at 0.08ºC warmer than 50 odd years ago is NOT.
And of course there is ZERO evidence that the 0.08ºC warming is from any human activity.
Do you have such evidence?
You have been TOTALLY FREE of it for a LONG time, seb
All you can manage is a pitiful plea for attention.
Are you really DUMB enough to think the whole of the ocean is focused just on warming a small area of the Antarctic?
0.08ºC, seb
Immeasurable to mercury thermometer.
Again, just calculate how much energy is necessary to warm an ocean by 0.08°C and compare it to the amount that volcanoes are putting out. It’s simple enough, why aren’t you able to do this and instead just trust your gut feeling or whatever it is that you do.
Solar energy warms the whole ocean, seb
Volcanoes are only warming that tiny part of the West Antarctic
You really don’t have a CLUE do you, gormless twit. !
Do you REALLY think that 0.08ºC warming can melt glaciers???? REALLY?????
Your anti-science ranting fantasies are complete.
The headless chook you like to impersonate has more brains.
Anyway, that TINY ocean warming is NOTHING to do with humans.
There is ZERO evidence that humans have any influence of ocean temperatures.
Prove me wrong, by answering two simple questions, seb. Or will your GUTLESS feelings triumph once again
Q1. In what way has the climate changed in the last 40 years, that can be scientifically attributable to human CO2 ?
Q2. Do you have ANY EMPIRICAL EVIDENCE at all that humans have changed the global climate in ANYWAY WHATSOEVER?
seb, do you any evidence that the volcanic melting in Western Antarctica is in any way caused by human CO2 ?
Any evidence that humans cause “climate change”, apart from data adjustment.
Or that human caused “climate change” causes volcanic melting?
Do you have evidence that volcanism increased in recent decades by significant amounts? If not, why does is melt more now than before?
Go out and read more. And no, don’t read stuff from your skeptic bubble … read papers that get posted outside your particular bubble. Widen your horizon!
“Do you have evidence that volcanism increased in recent decades by significant amounts?”
Yes, there is evidence of an increase in seismic activity around 2000.. Sorry you were UNAWARE of that FACT. Not unexpected.
“Go out and read more. “
ROFLMAO
Still taking the headless chook COWARDLY EVASION route, hey seb 🙂 So funny. !!
ZERO evidence of your own, so you want me to go and find it for you.
TOTALLY PATHETIC
and so totally expected.
Q1. In what way has the climate changed in the last 40 years, that can be scientifically attributable to human CO2 ?
Q2. Do you have ANY EMPIRICAL EVIDENCE at all that humans have changed the global climate in ANYWAY WHATSOEVER?
Just for once I will answer the troll.
Accusing skeptics of cherrypicking when this is the standard operating procedure of alarmists, is gross hypocrisy.
Also standard green/leftist tactic. Accuse the other side of what you are doing.
This!
What did you just do?
#facepalm
You mean “#facePLANT” in your case, seb
yet again.
Always being tripped up by your own BS.
And still….
Totally Evidence Free when it comes to CO2 warming anything, anywhere, anytime.
But the models give the “right” answer.
Water storage is decreasing because of climate change.
Simple!
Also back in 2015, Satellite data reveals that over the last decade, Africa, as a whole, has become both wetter and greener as noted HERE.
A new study led by the University of Leicester has concluded that there have been noticeable changes in rainfall across the African continent over the last ten years. The international research team was analysing satellite images of sub-Saharan Africa from a rain dataset produced by the Climate Prediction Centre of the National Oceanic and Atmospheric Administration (NOAA).
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Humm, I though the IPCC supposition (backed by utterly useless models) strongly suggested that places like Africa would get dryer not wetter.
GIGO – garbage in garbage out !
I would still prefer some real measurement data to back up the Grace data.
Because I still do not trust Grace data.
Agreed.
But I have zero trust in the models.
SebH is a waste of ink.