Study suggests that global sea level is less sensitive to high atmospheric carbon dioxide concentrations than previously thought.
From STANFORD’S SCHOOL OF EARTH, ENERGY & ENVIRONMENTAL SCIENCES
Ice sheets may be more resilient than thought, say Stanford scientists
But there may be some good news amid the worry. Sea levels may not rise as high as assumed.
To predict sea level changes, scientists look to Earth’s distant past, when climate conditions were similar to today, and investigate how the planet’s ice sheets responded then to warmer temperatures brought on by increased carbon dioxide in the atmosphere.
In a recently published study in the journal Geology, PhD students Matthew Winnick and Jeremy Caves at Stanford School of Earth, Energy & Environmental Sciences explored these very old conditions and found that sea level might not have risen as much as previously thought – and thus may not rise as fast as predicted now.
To better understand global sea level rise, Winnick and Caves analyzed the middle Pliocene warm period, the last time in Earth’s history, approximately 3 million years ago, when carbon dioxide levels in the atmosphere were close to their present values (350-450 parts per million).
“The Pliocene is an important analogue for today’s planet not only because of the related greenhouse gas concentrations, but because the continents were roughly where they are today, meaning ocean and climate circulation patterns are comparable,” said Winnick.
These similarities are why the Intergovernmental Panel on Climate Change (IPCC), the group responsible for global sea level rise projections, focuses on the mid-Pliocene warm period to inform their computer models.
Previous studies of the mid-Pliocene warm period used oxygen isotope records to determine the volume of Earth’s ice sheets and, by proxy, sea level. Effectively, the oxygen isotope records act as a fingerprint of Earth’s ice sheets. By combining the fingerprint with models of ice sheet meltwater, many previous researchers thought that sea level was likely 82 to 98 feet (25 to 30 meters) higher during the Pliocene.
Such high sea level would require a full deglaciation of the Greenland Ice Sheet and the West Antarctic Ice Sheet, and as much as 30 percent of the East Antarctic Ice Sheet – enough to cover New York City under 50 feet of water. But these estimates arose because the researchers assumed that the Antarctic ice of the Pliocene had the same isotopic composition, that is, the same fingerprint, as it does today – an assumption that Winnick and Caves challenge in their new report.
To understand the isotopic composition of Pliocene ice, Winnick and Caves began in the present day using well-established relationships between temperature and the geochemical fingerprint. By combining this modern relationship with estimates of ancient Pliocene surface temperatures, they were able to better refine the fingerprint of the Antarctic ice millions of years ago. In re-thinking this critical assumption, and by extending their analysis to incorporate ice sheet models, Winnick and Caves recalculated the global sea level of the Pliocene and found that it was 30 to 44 feet (9 to 13.5 meters) higher, significantly lower than the previous estimate.
“Our results are tentatively good news,” Winnick said. “They suggest that global sea level is less sensitive to high atmospheric carbon dioxide concentrations than previously thought. In particular, we argue that this is due to the stability of the East Antarctic Ice Sheet, which might be more resilient than previous studies have suggested.” However, a rise in global sea level by up to 44 feet (13.5 meters) is still enough to inundate Miami, New Orleans and New York City, and threaten large portions of San Francisco, Winnick cautioned.
While the study helps refine our understanding of Pliocene sea level, both Winnick and Caves point out that it’s not straightforward to apply these results to today’s planet. “Ice sheets typically take centuries to millennia to respond to increased carbon dioxide, so it’s more difficult to say what will happen on shorter time scales, like the next few decades,” Winnick said.
“Add that to the fact that CO2 levels were relatively consistent in the Pliocene, and we’re increasing them much more rapidly today, and it really highlights the importance of understanding how sea level responds to rising temperatures. Estimates of Pliocene sea level might provide a powerful tool for testing the ability of our ice sheet models to predict future changes in sea level.”
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Well it seems we need another ‘ology’ for this absurd ‘Sea Level’ claptrap.
Please make a suggestion to add to the list here,
http://users.tinyonline.co.uk/gswithenbank/ologies.htm
Duh – asshats – 2-3mm (CC) per year…
Finally a paper that more or less expresses, “it’s not as bad as we thought.” Perhaps this will be a new trend as some climate scientists try and minimize the “C” in “CAGW.” But politically speaking, this was bad timing for such a paper to come out just a few months prior to the Paris Climate Change conference.
What is also inconvenient to our friends on the left is what the tide gauges say if you do an honest evaluation.
I wonder if young future academic scientists see the handwriting on the wall.
Let’s hope that soon funding previously squandered on man-made global warming garbage will go to real climatological studies, or to reduce the national debt, so alarmingly doubled in just eight years.
Don’t hold your breath.
I just got this from a charity – you can imagine my reply. Another one to strike off the donation list: just like Oxfam, someone who thinks that climate change awareness puts food in peoples mouths.
“Did you see the email Kevin sent last week? We’ve just launched the Collective Future Speaking Tour – a series of forums looking at the urgent need to support the people whose livelihoods are most at risk of climate change.
As climate impacts push vulnerable people deeper into poverty, we’re bringing together activists from across the Asia-Pacific to share stories of how climate change has impacted their communities.
Register for your ticket today (get in quick before prices rise next week!).
The timing couldn’t be more urgent. Whether it’s devastating cyclones in Vanuatu, rising tides in Kiribati or crippling droughts in PNG, efforts to overcome poverty are being undermined by accelerating climate impacts.”
Do coalminers count?
I’m an engineer, not a “scientist”. I deal with reality, not conjecture. It only took man a couple of million years to realize the continents FLOAT on a sea of molten rock. Plate tectonics is reality. Now, armed with this non-climate-funding-generating knowledge, WHAT IF the PLATES are also going UP AND DOWN?! We know the islands, like the Malvinas, are going up and down from the underlying volcanic pressure that made the island in the first place. And, we know the plates pull apart and subduct, pushing this plate up by the plate diving under that plate. What LOOKS like a sea level change, especially in mm COULD just be the plates moving up or down the gage is mounted on! Sea level is a RELATIVE depth, not an absolute.
The other inconvenient physics I’ve been thinking about in this “floating” tectonic plate nonsense is…..
What happens to the FLOATING plate if the mass of it changes? If a plate had nothing on it, climate changed (I’ll pander, I can be bought) and the desert island became a jungle island loaded with millions of tons of living and dead vegetation, animal life, etc. or (once again pandering to the human caused religions) man started hauling off millions of tons of valuable minerals, transferring that mass from here on one side of a plate to there on the other side of the same plate, or to another plate, entirely. Will the plate with less mass float UP, like any ship we just unloaded or DOWN like a supertanker we just filled with oil? If not, why not? If nothing else were to change, and I admit everything is changing constantly, wouldn’t this simple, grade school physics of floating bodies on a liquid rock plate move the gage up or down making the perceived sea level move up or down from the RELATIVE vertical position of the plate we’re using as a REFERENCE to measure sea level by? Well? Duhh!
At first I didn’t think that human activity could “tip” the tectonic plates, but you convinced me with the ALL CAPS.
Isn’t Guam in imminent danger of capsizing?
OK Larry, can you say it plainly?
Do you think plate tectonics is hooey?
That the principle of isostasy is bologna?
It is hard to tell from the typed word if a person serious, delirious, or merely being sarcastic.
They do mate and you are essentially correct
Not from variations in the mass of critters and plants but certainly from ice.
A lot of the northern northern hemisphere is still rising due to the melting of several kilometres of ice.
https://en.wikipedia.org/wiki/Post-glacial_rebound
It just doesn’t happen quite as quickly as pushing a rubber duck down in the bath and letting it go
Yes Larry. It is a phenomena called isostacy. But for all practical matters the mass of vegetation is entirely trivial. However, the mass of an ice sheet is an entirely different story.
The weight of ice does indeed press down on continental plates. Hudson Bay exists because of the mass of the now melted Laurentide Ice Sheet. The plate there is rebounding from being freed from all that weight, while the Atlantic coast is falling.
Tectonic plates are an observed, scientific fact. Science can measure them moving apart, thanks to seafloor spreading. Science can observe the subduction of thin oceanic plates under continental plates moving over them. Rocks and fossils on different continents show where and when they were conjoined.
Maybe it’s a fact which for some reason you don’t like, but nonetheless a fact.
The Los Angeles tide gauge has been sinking at a quite linear rate of 0.88 mm per year since 1924. Is any of that due to the 25+ tons of tar that’s been seeping out of the coastal sea floor for thousands of years?
[And the oil pumped out from the LA Basin from 1915 – 2015. La Brea is the “seep” of asphalts that are the surface leakoff of the deeper oil pools. .mod]
Darn, left out the word “daily” after “25+ tons.”
Before the oil was pumped from the LA Basin, the tar was dug up from Carpinteria.
At Carpinteria, south of Santa Barbara, liquid asphaltum seeps from the hillside onto the beach. Back in the late 1800s, Carpinteria was the asphalt capital of the world. The asphalt mined there paved roadways throughout the country.
When the Carpinteria lode was dug up, the mining moved to Goleta. The Alcatraz Asphaltum Mine operated from 1890 to1898 on what’s now the UCSB campus.
Watch this old Huell Howser program:
https://blogs.chapman.edu/huell-howser-archives/2006/09/29/carpinteria-state-beach-californias-golden-parks-141-2/
And here’s some Goleta history:
http://www.edhat.com/site/tidbit.cfm?nid=135790
I think it may take more than 25 tons, or even 25 million tons, to make the state of CA rise or fall into the crust.
Also, it takes a very long time for this process to play out, even when sufficient weight is applied or removed to make a whole region sink into the crust or pop back up. It may be that the glaciers that melted in the Sierra are still exerting an effect. Or, more accurately, the crust is reacting to the weight being removed.
The East Coast is still reacting to the glaciers which disappeared over twelve thousand years ago. Why not CA?
But separating out the tectonic from the isostatic effects may be a matter of guesswork to some degree.
91 million tons over the last 10,000 years, and that’s just one area of seeps off the Goleta coast! But, yes, it’s doubtful it has much to do with sinking plates or tide gauge readings.
The heavy stuff stays where it seeps, forming asphalt volcanos. The lighter stuff bubbles to the surface, where the hydrocarbons evaporate. What’s left then sinks. So, basically, it’s just a source of atmospheric methane, oily feet, and food for bacteria.
If Californians weren’t such ignoramuses, they’d be promoting oil and gas extraction off the coast. Not only would this reduce the amount of tar on the beaches (reduced gas pressure = less seepage), the sea floor would subside, making more room for water and thus reducing sea level. ☺
The mod’s comment reminded me of news articles in the 60s about land subsidence in Huntington Beach, where some locations had dropped as much as 6 ft. A search on this topic showed that the greatest surface drop was in the Wilmington oil field around Long Beach, where land at Wilmington subsided more than 29 feet between 1926 and 1953. The subsiding has since been reversed by pumping more volume of sea water into the wells than the oil extracted.
http://www.saveballona.org/gasoilfields/WilmSubGC.pdfield
The Los Angeles tide gauge is located at the edge of the Wilmington oil field. The subsidence is obviously localized, or the gauge would not show a fairly consistent rise of 3.4 in. every 100 years.
Not likely, since the density of the tar is roughly the same as water.
Yes, engineers have an advantage. Also, people that go to liberal schools are taught what to think not how to think. They must invent their own reality either personally or collectively. Students now have to worry about causing a micro-agression or using the wrong pronoun. Real science is in some deep sh…… Reality has become a relative concept.
Larry Butler:
“I’m an engineer, not a “scientist”. I deal with reality, not conjecture.”
Your problem is you know too much to be sure of anything.
“Sea levels may not rise as high as assumed.” I love that part. The phrasing is superbly ironic.
Windmills may not be as green as assumed.
Hurricanes may not be as severe as assumed.
Jonesy may not be as smart as assumed.
Mann may not be as stupid as assumed.
…..no wait…Mann IS as stupid as assumed!!!!
Damn. I hate it when a theory falls apart. It makes me feel just like a climate scientist.
Pamela, that was funny! You may be funnier than you thought, or I more easily entertained. Either will do.
I can show you where to find scallop fossils in Wyoming. Sea musta been there some time.
Or else it was an old lake bed.
Who released the CO2 that caused the warming that caused the drought that made the lake dry up?
Huh, smarty pants?
So walking chicken little back into the egg?
I was under the impression that large polar ice sheets are what distinguish the Pleistocene from most of the rest of earth history. I didn’t think there were big ice sheets in the Pliocene, or at any time in the Cenozoic or Mesozoic. Maybe my geology is out of date. In fact it’s more than likely. Somebody tell me where I am wrong, please.
In a nutshell, Climate in the Pliocene was heading downhill. Eocene, quite warm > Miocene, getting colder>Pliocene much colder >Pliestocene bouncing and scraping bottom.
I wonder sometimes if a world vote were held, if people would be willing to trade the coastal cities of the world for the assurance that the Pliestocene glaciation were truely over.
Apples and oranges! The hockey-stick had not even been invented way back then!
Was Michael Mann part of this study?
I mean think it through. They used a new way to estimate SLR and came up with a different number than the old way to estimate it. No shock there. If the numbers matched it would have been a shock. Problem is that the numbers got better, not worse. Now we all know that’s just not what those who fund climate science are paying for. Things always have to get worse, or you don’t get anymore funding.
So… it seems to me that this result has been caused by a simple mistake. A glaringly obvious mistake that reversed their results….
They got their proxy data upside down…
So much Blood, Sweat, Toil and Tears from the alarmist over 3 millimeters (the average of the TOPEX-Posiedon/Jason/JasonII …. blah blah blah).
Like in politics, “No one lives at the Federal Level, and no one lives at the “average”!, it is all local!
And that is what Global Warming, Climate Change and Climate Science are … Politics.
Have you had your Poli-Ticks vaccinations today?
Alfred Wants To Know.
Ha ha
I’ve said it before, and I’ll say it again…What is the elevation of Mt. Everest, within 3mm? What’s that? You can’t tell me, and it’s not even rolling like the waves of the friggin’ ocean?
So much uncertainty here. Subsidence, isostatic rebound, WAVES, storms, tides, etc. How confident are we REALLY that we have a reliable means to measure sea level? Other than that small set of tidal gauges in places not subject to near-term tectonic/glacial/subsidence factors?
Wait… Mount Everest?
Sea level?
What is meant by the term, anyway?
So it would appear that global average sea level is as meaningless a concept as global average temperature.
Walt – yes I think that is about right, it is meaningless which makes it a wonderful instrument for people to make it mean what ever they want it to mean.
“… enough to cover New York City under 50 feet of water …”
Sigh. Why do people feel the need to write such highly suggestive and misleading statements. It evokes images of the tops of skyscrapers 50 feet below the water surface – and that per chance happening maybe overnight? Cue in mental images of Kevin Costner…
Sure, a threat of a 50 feet rise in sea level would be bad news for New York – not to speak of probably billions(!) of people all over the world living in coastal regions all over the world! But when neglecting to tell audiences that such a rise would only be possible over the course of millennia(!), this is somewhat galling.
And that no less in a press release meant to set the record straight on those possibly inflated sea level rise numbers being handed around. Oh well.
I apologize for my sarcastic remark in advance, but I can’t help to think: “Oh no! The sea level is rising by inches per decade! I will have to flee from this monstrous sea level rise! I hope the sea does not outrun me!”
I haven’t read either the article or the thread or anything else to do with this subject but I know, I just “know” it’s junk/voodoo/Koch-funded science.
I’m glad I got that off my chest….
I don’t think Chas. Koch has funded climate research since his charitable foundation was accused of trying to “buy” Muller’s Berkeley Earth with a $150K donation, even though six other identified foundations donated a total of $1.25M, taxpayers donated $188K through Lawrence Berkeley Labs, and an as yet unidentified “Anonymous Foundation” donated $800K. The only donation with (unspecified) conditions attached was $100K from the Energy Foundation, shortly after Tom Steyer gave them $500K.
Oh look the American President is going to take the blame on behalf of the American people for every extreme weather event in the world
http://www.bbc.co.uk/news/science-environment-34147192
“Poorer countries want compensation for extreme weather events that they link to large scale carbon emissions.”
Unfortunately for people like a Obama it is a no-lose situation, when this global warming scare implodes or quietly disappears into the sunset as a footnote to stupid, Obama can say I acted with vigor on the best advice of science to protect our planet. It deflects responsibility, (remember “it’s Bush’s fault”) and shows a lack of character but has been very effective for him politically. Which perhaps says more about the American electorate than Obama.
Is anyone who has read this paper able to give us a quick resume of the methodology?
What’s puzzling me is that the Oxygen Isotope ratio is a major proxy for the temperature. If the authors are saying that the calculation doesn’t work for the Pliocene, then maybe it doesn’t work for Pliocene temperatures either. Or are they revising the fractionation of O-18 in ice alone, and for the Pliocene alone?
Some info is missing here.
Would be nice to know before we take too many lessons from it
This is actually good news for Alarmists. “It’s not as bad as we thought” simply means “there’s still time to fix this”. So, for example, even if the upcoming klimate klownfest doesn’t accomplish much, the message is “don’t despair (yet), because all we have to do is roll up our sleaves and work still harder.”
There’s a method to their madness.
Every time I read a report on the effects of CO2 that I think of a blind man holding the tail of an elephant and concluding elephants are a type of snake.
The global eco-system is huge in it’s complexity and constant adaption and variation with many feedbacks and counter feedbacks. Climate scientists act like fortune tellers who claim by looking at a persons palms as babies can then predict their future adulthood. (Apologies to palm-readers out there who probably have better track record of prediction than climate scientists.)
Scientists have to stop with these half-assed 50 year, 100 year predictions, science is figuring out how stuff works and applying that knowledge where possible. Currently there is gross misunderstanding between cause and effect and fortune telling.
The earth is very tiny and the Local Star is immense. We are the size of a flea compared to our Local Star. Anything happening on this flea sized planet is dwarfed by anything, say some sun spots…happening on this peculiar nearby star which we circle quite helplessly.
Thinking that driving an SUV is more powerful than this huge star is just insane.
http://www.theonion.com/article/scientists-trace-heat-wave-to-massive-star-at-cent-21088
Most amusing….(c;]
This week’s issue of one of the UK computing mags (Micromart) has a feature about the EarthNow App from NASA. It can be downloaded to a desktop as well as a smartphone and i did so. (I expect most of you are familiar with this – I am trying to catch up).
There are a number of maps and datasets relating to the earth climate and some near real time images of data from remote sensing satellites , including sea level, global temperatures and various atmospheric gases.
One of these is CO2 up to July 2015, from , it says, the AIRS satellite launched over 10 years ago.
I thought that the CO2 sensing satellites were the Japanese IBUKI and US OCO- 2, the last released image /data from which relates to Dec 2014 . But AIRS is giving much later data . Do the 2 NASA/JPL satellites agree?
If AIRS can give near real time data for water vapour , ozone and CO , what is the problem with CO2?
Reblogged this on gottadobetterthanthis and commented:
Worthwhile article. The science isn’t settled. Science never is.
The lead graphic and first sentence are laughably inconsistent. The graphic states that it depicts what earth will look like with 6000 millimeters of increased average sea level. Not scary by itself. Not scary at all when considering that sea level is currently measured to be rising at about 3 millimeters per year. Accordingly, a linear extrapolation gets us out 2000 years hence.
Looking around the internet for examples of old photos that can show sea level, and current photos of the same location can provide as many examples as you care to review. One cannot tell that significant change is occurring overall. We aren’t talking about flooding cities. Sooner or later coasts change. Some coastal locations will go under water, others will have the ocean shore recede. Sooner or later everywhere changes. England has locations lost to the sea, and landlocked villages that used to be on the seashore. And that is just on that small island.
Everything changes. Always has. Always will.
It is also important to note that alarmists spin the rate of sea level rise. They like to claim that the current sea level rise rate of 3 mm per year is three time more than in the recent past. First, they are comparing apples and oranges. Second, that is playing fast and loose with the known facts. It is most practical to say that the sea level rise rate has been between one and three millimeters per year for thousands of years, all of our historical past. There really is no practical way to be afraid of something continuing to happen that has, for practical purposes, always happened.
Here’s something I’ve never heard anyone else bring up……
It seems to me, that the reason it is so difficult to ‘prove’ that the rise of sea levels is caused by something like polar ice caps melting, is because the sea levels do not fall when the polar ice cap grows- since we cannot ‘prove’ the ice cap theory (other than the observation I just made), isn’t it more logical to assume that sea levels change because of the movement of the Earths crust along with subduction, tectonic plate movement etc.? Because that is what seems to be the case, and that is at least something provable.
Timothy,
Not sure what you mean by polar ice caps, but the Antarctic ice sheets would have to count. I assume you would include the continental ice sheets than form on North America, Greenland, Europe and Asia during glacial phases.
Sea levels do fall when such “polar ice caps” expand and rise when they melt. During the last glacial maximum, when ice sheets covered much of the northern continents and the Antarctic ice sheets expanded, sea level was about 400 feet lower than now.
As the northern ice sheets, except for Greenland, melted and the Antarctic ice sheets got smaller, sea level rose 400 feet. In fact more than that, since sea level was higher earlier in the Holocene interglacial than now.
Since the rate of sea level rise has NOT increased since 1900, and since we know that the Antarctic and Greenland ice sheets are melting at an increasing rate (because the BBC says so on an almost daily basis), it is hard to fathom how these two trends could occur simultaneously.
Since, all that water must be going somewhere.
BUT WAIT, did I not just use the word “fathom”, and is this not a serendipitous clue.
The only possible explanation can be that the floor of the oceans is sinking.
Or perhaps some previously gas filled void under the sea floor has opened up, and all the extra meltwater is being displaced by the water that is currently rushing into this giant chasm.
They laughed at Alfred Wegener when he said that the continents float about and bash into one another like dodgems.
When this giant seawater swallowing void is finally discovered, I would like it to be named after my WUWT login moniker. The great chasm of Indefatigablefrog.
Fame awaits me…
(erm…parts of the above may be slightly sarc. But not the principle thesis, which will stand the test of time!!)
Sorry, Froggy, but you may croak before your dream is realized.
“The correction for glacial isostatic adjustment (GIA) accounts for the fact that the ocean basins are getting slightly larger since the end of the last glacial cycle. GIA is not caused by current glacier melt, but by the rebound of the Earth from the several kilometer thick ice sheets that covered much of North America and Europe around 20,000 years ago. Mantle material is still moving from under the oceans into previously glaciated regions on land. The effect is that currently some land surfaces are rising and some ocean bottoms are falling relative to the center of the Earth (the center of the reference frame of the satellite altimeter). Averaged over the global ocean surface, the mean rate of sea level change due to GIA is independently estimated from models at -0.3 mm/yr…”
— http://sealevel.colorado.edu/content/what-glacial-isostatic-adjustment-gia-and-why-do-you-correct-it
It does make sense. The H2O has moved from the land to the sea, and the sea bed is sagging. But as more water melts into the sea, won’t the sea sag more to accommodate it, pushing the continents ever higher as the mantle is shoved under them?
They probably watched this Video and thougth OH -SH*T
I refrained from watching the video a second time, and still thought “OH-SH*T” on your behalf.