By Dr. Patrick Michaels from World Climate Report
Sea level rise is a topic that we frequently focus on because of all the gross environmental alterations which may result from anthropogenic greenhouse gas emissions, it is perhaps the only one which could lead to conditions unexperienced by modern societies. A swift (or accelerating) sea level rise sustained for multiple decades and/or centuries would pose challenges for many coastal locations, including major cities around the world—challenges that would have to be met in some manner to avoid inundation of valuable assets. However, as we often point out, observational evidence on the rate of sea level rise is reassuring, because the current rate of sea level rise from global warming lies far beneath the rates associated with catastrophe. While some alarmists project sea level rise of between 1 to 6 meters (3 to 20 feet) by the end of this century, currently sea level is only inching up at a rate of about 20 to 30 centimeters per hundred years (or about 7 to 11 inches of additional rise by the year 2100)—a rate some 3-4 times below the low end of the alarmist spectrum, and a whopping 20 to 30 times beneath the high end.
To get from here to catastrophe surely requires a significant acceleration in sea level. And, because disasters pay scientists handsomely, a lot of people have been looking. Here is how the Intergovernmental Panel on Climate Change (IPCC) in its Fourth Assessment Report summed up its investigation:
Global average sea level rose at an average rate of 1.8 [1.3 to 2.3] mm per year over 1961 to 2003. The rate was faster over 1993 to 2003: about 3.1 [2.4 to 3.8] mm per year. Whether the faster rate for 1993 to 2003 reflects decadal variability or an increase in the longer-term trend is unclear. There is high confidence that the rate of observed sea level rise increased from th3 19th to the 20th century, the total 20th-century rise is estimated to be 0.17 [0.12 to 0.22] m.
Since 2003—the last data assessed by the IPCC—the rate of sea level rise has slowed (Figure 1).
Figure 1. Decadal (overlapping) rates for sea level rise as determined from the satellite sea level rise observations, 1993-2011 (data available from http://sealevel.colorado.edu/).
This observation seems to tip the scale to “decadal variability” rather than an “increase in the longer-term trend” in explaining the 1993 to 2003 behavior.
But there is much more evidence that no anthropogenic global warming-related acceleration of sea level rise is taking place.
A couple of months ago, an important paper was published that examined the changing historical contribution of ground water removal (for human water needs, primarily irrigation) to global sea level. A primary finding was that this non-climate component of sea level rise was both significant and rapidly increasing, currently making up between 15 and 25 percent of the current observed rate of sea level rise. Further, the rate of ground water extraction has been increasing over time, which imparts a slight acceleration to the rate of sea level rise over the past half-century or so. Once this non-climate signal is removed, there remains no evidence for a climate-related acceleration. We covered that finding here.
Another paper has just been accepted in the journal Geophysical Research Letters that identified multidecadal cycles in the historical mean sea level observations from many ocean basins. A research team led by Don Chambers from the University of South Florida examined tide gauge records from across the globe and found oscillations with a period of about 60 years in all ocean basins except the Central/Eastern North Pacific. Chambers et al., note that a 60-yr quasi oscillation has previously been identified in other earth/climate systems including ocean circulation, global mean surface temperatures, large-scale precipitation patterns, and atmospheric pressure, among other things. Many of these cycles can be traced back hundreds of years—an indication of a natural (rather than manmade) origin.
Chambers and colleagues note that given the strong possibility for such cycles in the global sea level data, that care must be taken when attempting to identify accelerations, as they, in fact, simply be upswings in the natural oscillatory behavior. For instance, in most ocean basins, the bottom of the cycle was reached in the 1980s and an upswing has been occurring since then—precisely when the IPCC notes that the rate of sea level rise has been increasing. For this reason, Chambers et al. note:
The 60-year oscillation will, however, change our interpretation of the trends when estimated over periods less than 1-cycle of the oscillation. Although several studies have suggested the recent change in trends of global [e.g., Merrifield et al., 2009] or regional [e.g., Sallenger et al., 2012] sea level rise reflects an acceleration, this must be re-examined in light of a possible 60-year fluctuation. While technically correct that the sea level is accelerating in the sense that recent rates are higher than the long-term rate, there have been previous periods were the rate was decelerating, and the rates along the Northeast U.S. coast have what appears to be a 60-year period [Figure 4 of Sallenger et al., 2012], which is consistent with our observations of sea level variability at New York City and Baltimore. Until we understand whether the multi decadal variations in sea level reflect distinct inflexion points or a 60-year oscillation and whether there is a [Global Mean Sea Level, GMSL] signature, one should be cautious about computations of acceleration in sea level records unless they are longer than two cycles of the oscillation or at least account for the possibility of a 60-year oscillation in their model. This especially applies to interpretation of acceleration in GMSL using only the 20-year record of from satellite altimetry and to evaluations of short records of mean sea level from individual gauges. [emphasis added –eds.]
The bottom line is this: the more people look for the anticipated acceleration in the rate of sea level rise, the less evidence they seem to find in support of it. All the while, we eat into the 21st century with a rate of sea level rise not much different from that experienced during the 20th century—and one which was hardly catastrophic, readily proven by a simple look around.
References:
Chambers, D., M.A. Merrifield, and R. S. Nerem, 2012. Is there a 60-year oscillation in global mean sea level? Geophysical Research Letters, doi:1029/2012GL052885, in press.
Wada, Y., et al., 2012. Past and future contribution of global groundwater depletion to sea-level rise. Geophysical Research Letters, 39, L09402, doi:10.1029/2012GL051230.
I am not aware of any change in sea level in my lifetime or the lifetime of my local quay. How is this rise in sea level being detected? In fact what is sea level supposed to mean?
Get a spring tide coinciding with the wrong atmospheric conditions and a storm surge can occur such as happened in the Thames Estuary in 1953 causing great loss of life, an event that has largely been neglected. That great flood was nothing to do with a rise of sea level and has not happened since but if it did happen again and it probably will then I am certain that the media and the BBC will blame it on man made global warming causing a rise in sea levels.
It’s a sure thing. The climate is in the process of rolling over to a cooling phase and sea level decrease should continue, but it’s just not as fast as I first guessed a few years ago. But OTOH, I was not a climatologist then either.
With enough ice breakers, at least twenty on order right now I am told, many nuclear, mankind should be able to slice and dice the Arctic Ocean enough to keep it free of ice pack at least half of the year with the north passages established and the development of the north platform fields in place.
Seems what is really needed now is to double or triple the flow of activists and environmentalists with their ‘studies’ (vacations) toward the North Pole to finance the whole shebang.
☺-wayne
@Latimer
The sea does not inundate them, it floats them. The estimates are that this will begin to happen in the 2050 range and continue for hundreds of years.
Actual observation shows it’s already in progress. Pine island glacier is already thinning and floating over hundreds of meters of it’s length. As the sea levels continue to rise it raises the shelf more and allows more salt water under to continue the thinning.
Of course the estimates were created to give Politicians something to present. Politicians who don’t really want to hear the news.
This is besides the point. 1mm will destroy our society over 2 centuries, 2mm just makes it faster. 3mm guarantees that our grandchildren pick up the check, 4mm our Children.
The rise in the last century just set the scene. The world no longer has space for populations to move to when things change. The only thing sea level rise can contribute is war and misery. Yet it is dismissed as a minor irritant. Well it may be for some in the West…..
I discussed this with my Brother many years ago. My point was that I would not be caught in all this because I was aware. His point was that aware or not, those who didn’t care would simply come in numbers and take what I had.
Look in the mirror and decide which you are. Prepared or a taker. Lots of the attitude on here is a taker attitude. Most in the AGW camp are “aware”. if the cap fits, wear it.
@Bob says:
>Does anyone expect sea levels to remain static?
Wasn’t it Fairbridge that investigated the rise and fall of sea level using the East Coast of Auz as a source of information? He found that there were quite rapid changes of 2 metres (!) in the past few thousand years both up and down. Not so? I recall reading the paper many years ago.
It is a general assumption that sea level only changes slowly and that it is all about forecasting long term trends. His examination of actual shorelines tells a very different story. The shore ridges in Hudson Bay seem to tell a different story (over a very long period, of course).
There is also some interesting shoreline information from the Welsh coast and eastern Ireland. The shorelines are not sequential at all, and they are tilted slightly differently giving credence to the theory that slight (and sudden) changes in the tilt of the Earth are common. In Paul Dunbavin’s book he proposes a mechanism for this. The first three chapters are probably the best accessible description of how pole shifts wobble and work (the Earth has three ‘poles’ which are rarely, if ever, aligned).
There is a big difference between a local change in sea level and a global rise in sea level. A tilt change of 0.5 deg causes no perceptible sea level change at the poles and equator, but a 1000 ft change at 45 degrees Latitude. In brief, the cause is because the Earth is a rotating oblate sphere mostly covered by a liquid.
Otter says:
September 13, 2012 at 2:52 am
‘One only has to step outside to see climate change.’ – mcFibben et al
NO.
One only has to step outside to see that everything is going pretty much as it always has.
Not so,Otter.As I sit here typing this,the lake outside my front window has encroached at least 2 mm closer to me.And it’s on fire! OMG. errrrrr….sorry.Gunner informs me it is the sunrise,which seems to be decelarating at an amazing rate,at least until the time change happens.And that 2mm rise?About 200 hundred Canuck geese displace that much water. And really Otter.Shouldn’t you be happy with more water to play in?
A picky correction: the smallest prediction listed is 3 feet by 2100 which is 36 inches. 7 inches per year times 5 gives 35 inches by 2100, so it should read 3-5 times not 3-4 times.
NeilT wrote, “Those glaciers are the only barrier to the great ice fields coming back to earth.”
So you are expecting a cooling Earth? Got it. Catastrophic global weirding at its best intellectual display.
A couple of months ago, an important paper was published that examined the changing historical contribution of ground water removal (for human water needs, primarily irrigation) to global sea level.
Two to three years ago, I pointed out on WUWT, that using the UN numbers for groundwater extraction for irrigation alone, that amount of water would add as much as 2mm per year to the sea level.
Guys
NeilT is clearly young and naive and believes he can persuade others by “The yah boo sucks to you” kind of argument. He is new here and obviously educationally challenged in that he has a very poor grasp of the facts.
So perhaps it would be nice if he was treated nicely and not sliced and diced as is the usual case for those who support the objectives of the global warming industry.
Another dose of hysteria-quenching reality. Thanks, Dr Michaels. In this age of post-normal science we must, like Diogenes, search diligently for an honest man, ever aware that much of what we hear is lies.
NeilT;
Two years solar minimum, 6mm absorbed into the warmer atmosphere and falls as titanic rainfall, massive floods, huge storms and that’s supposed to be a GOOD thing.
>>>>>>>>>>>>>>>>>>>
That may be a new record for the most things wrong in a single sentence
Two years solar minimum is assocoated with LOWER temps, not warmer.
Colder air holds LESS water not more.
NASA’s own measurements show that atmospheric water vapour has been falling, not rising.
We just got done with screaming and hollering about droughts in the US being caused by global warming, not floods.
Huge storms? One recent hurricane doesn’t a trend make. The Total Cyclone Energy has been falling and falling dramatically for years.
I’m not certain if you are a clever troll who managed to inject a considerable amount of inaccurate information into a single sentence, or if you actually believe what you wrote. I suspect the latter, and suggest that you familiarize yourself with the actual data before quoting it. As for your quip at the end of your tirade about us not taking you with us, that goes both ways my friend. The various schemes for reducing CO2 emissions come with some rather draconian results of their own, and these are certain results, not “projections” that would be disasters for billions of people. I’m not talking about having to move, I’m talking about starving to death. So please, don’t take US with YOU.
Wayne, Pleaaaase!! Here in Canada it costs enogh just to produce icebreakers that venture into the Arctic in summer. In winter they retreat to the Gulf of St. Lawrence and try to keep the sea lanes open there in January and February. How much of our GDP are you expecting us to shell out to get our icebreakers to do any more than they are now doing? And why would we want to, anyway? There is no requiremen t to do any more than we are now doing.
Very well said Dr. Michaels. Perfect Clarity.
Gee whiz, I hope the good doctor doesn’t offend the sensibilities of those still insisting they’re all in it with good intentions, and that it’s all a true scientific dispute without political overtones and financial gain.
It’s all of the above.
Hey NeilT, I was at the beach yesterday. It was no different 50 years ago. No catastrophe there. No “titanic rains,massive floods, huge storms” It was all good. No evidence of catastrophe, No matter that you hope against hope for it to be true. You can’t show it.
The science of evaluating geologic records to understand long term sea level change and it’s effect on coastal processes was pretty much invented by Exxon. Understanding of sea level and coastal processes is very important to oil exploration scientists because many future oil reservoirs are formed at shorelines and delta fronts. Nobody knows more about the history of sea level than Big Oil.
NeilT said “I can see the continued rise even if you can’t….”
The continued steady rise in MSL is not the issue – the rise (dMSL/dT) just represents the steady and constant recovery from the LIA, as from well before the industrial era and, yes, this will slowly inundate littoral areas but since it well predated industrialisation can have nothing to do with CO2.
It is only if there had been an acceleration (an increase in the rate of rise with d^2MSL/dT^2 > 0) within the industrial era that one could say with justification that the rate of run-off from land-based ice into the oceans had increased – so infer that global surface temperatures had increased within the industrial era. For myself I cannot see any acceleration in the MSL time series as shown for the last 20 years. The series shows a rise, but not an acceleration – so nothing unusual is happening.
NeilT says:
September 13, 2012 at 6:32 am
A little more research would have prevented that you didn’t know the real facts… Most of the outlet glaciers in Greenland (and the WAIS) are already floating and did that for centuries. What is visible and going on since the depth of the LIA is that the breackup point goes back and forth, depending of a complex play of snowfall on the top of the ice field, the melting at the edges, the total pressure of the ice near the outlet and the resistance of narrowings and debris.
The breakup point of the largest glacier in Greenland at Illulisat/Jacobshavn has moved inland since 1850, with the largest move in the period 1935-1950, then the breakup point moved forward towards the sea, but since 1995 is moving back again. See:
http://www.ferdinand-engelbeen.be/klimaat/greenland_glacier.html
NeilT-
“Most in the AGW camp are “aware”.”
Interesting.
Depending on the survey, more than 100 million ‘aware’ Americans agree with your apocalyptic predictions of CACC hitting the proverbial fan. To avoid the current situation of you believers coming across as blatant hypocrites, when can the skeptics and luke-warmists expect you and your carbophobic horde to zero out your personal carbon footprints? No carbon credit scams allowed. Cost is no barrier, as you *know* the damages will be infinite. I trust the birthrate among the faithful horde is already zero point zero, as you pro-climateers are aware that every new American baby is a 1600 ton carbon bomb that pushes us closer to climate doom.
I await seeing the beginnings of a tipping point when the pro-climate congregation acts on its own beliefs with its own money. So far, even the pro-climateer leaders have eschewed any sort of personal sacrifice to Gaia, although UN IPCC bellwether R. Pachauri recently committed to a smaller personal carbon bootprint when he is reincarnated.
NeilT @ur momisugly various posts above:
If we go back to MIS-19 we can see three distinct thermal excursions right at it’s very end. That was at the Mid Pleistocene Transition about 800 kyrs ago. http://wattsupwiththat.com/2012/03/16/the-end-holocene-or-how-to-make-out-like-a-madoff-climate-change-insurer/ Read further in this piece and you will soon find citations for a possible +21.3 M sea level excursion during the long broad thermal peak at the end of MIS-11, the last half of which is often cited as orbitally the closest match to the end Holocene. The last interglacial back, also an extreme interglacial appears to have had two strong thermal pulses right at its very end, the second one netted somewhere between a +6 to a +45 M rise in sea level, right at its end (read the link above all the way through).
So let’s play “Fantasy Sea Level” for a moment. Since it’s a fantasy, all of us sign-on, willingly or unwillingly, to do whatever we possibly can to quell whatever prognostication of CAGW sea level rise anyone wants to choose. And then we actually do it. Again, since this is fantasy game playing, it is now 2100 and we are all still here, and at a giant earth party, drinking non-carbonated champagne of course, slapping each other on the back congratulating ourselves for an AGW SLR quash-job well done!
But, but, sea level goes on up +6 or +21.3 or +45 M anyway, because for whatever reason, this just seems to happen at the end extreme interglacials.
“How do you feel? How do you feel? How do you feel?” — Computer, “I do not understand the question.” — Spock (NeilT), “What’s the matter, Spock(NeilT)?” — Amanda, “I do not understand the question, mother.” — Spock(NeilT), “Well, your half-human. The computer knows that.” — Amanda, “The question is irrelevant.” — Spock (NeilT).
Yes, the question of whether or not humans are causing SLR may in fact turn out to be irrelevant at an end extreme interglacial……… So how do you feel, now, NeilT? Assuming that you actually took the time to gain a little knowledge reading the linked essay above, all the way through.
Where is Trenberth with a pithy phrase when we need him. The travesty is that the oceans are missing water and we cannot explain where it is. We know the glaciers and polar ice (well, the north pole, at least) are melting and the water must be somewhere. Maybe the water is hidden in the depths of the oceans.
oops…..forgot “/sarc” tag at 8:38 am
Dodgy Geezer says
The world is throwing away all its historically stored groundwater into the sea!
Good one!
I can only hope that the environmental movement will come to recognize the importance of “fracking” — that it will help restore those groundwaters. Pump that water back down!
Not as funny as yours but I had to add a little something.
Eugene WR Gallun
It may be time to do another post on anthropogenic CO2 and atmospheric CO2 as measured at Mauna Loa.
The Chinese are throwing vast quantities of CO2 into the air; but I am not sure I see it in the atmospheric data. Or is it? It would be interesting to see a thoughtful post on the matter.
A Warmist says:
September 13, 2012 at 6:06 am
“Its all lies I tell you…lies!”
It is a tale
Told by an idiot, full of sound and fury
Signifying nothing.
NeilT says:
This is besides the point. 1mm will destroy our society over 2 centuries, 2mm just makes it faster.
It is only Sept, and the competition is no doubt going to be tough, but I’d still wager that statement hangs on to become the dumbest GD thing said about ‘global warming’ this year.
1mm/yr * 200yr = 200mm = ~8 inches over 200 years.
Sea level rise over the 100 years from 1900-2000 was about 8 inches. Somehow, people were able to cope – in the process increasing the size of “our society” from about 1.75 to something over 7 billion people.
Have you considered how you are going to spend the prize money, Neil?