I got a couple of emails today saying that I should take a look at the most recently posted sea level graph from the University of Colorado shown below:
The reason for the interest is that it dropped the rate of change from 3.3 mm/yr to 3.2 mm/yr. as shown in the next graph. That’s hardly news, since it is well within the error band of +/- 0.4 mm/yr.
But I thought it might be interesting to go back and see what I could find in the UC sea level archive of graphs. I’ve presented all of the ones I’ve found below. I should note that in some years, UC may only release 2 graphs (as indicated by the release #) or up to 5 in one year like they did in 2005. For the sake of presentation simplicity, I’m only presenting the last graph to be released in any year.
I realize there has been a great deal of interest in the flattening of the 60 day smoothing line that started in 2007 and continues to the present. But the trend line will take awhile to reflect any appreciable change in the rate if it continues to flatten. The yearly rate of rise has been between 3.0 and 3.5 mm per year since 2004.
Many projections by various models predict the rise of sea level:
Note the trend of the observations line from 1950 to 2000, if you follow the linear trend, it will end up somewhere between 20 and 30 cm by the year 2100. The graph above is from Wikipedia’s “global warming art” which for some reason doesn’t show the observations back that far.
Here is a better graph, from New Zealand’s Ministry of the Environment, which shows more of the historical record, all the way back to 1870:
It seems sea level has been rising for awhile, and that the observation line in black, if you follow the linear trend, will also end up somewhere between 20 and 30 cm by the year 2100.
To put it all in perspective, some example images are useful.
Here is what 3 millmeters of sea level rise in 1 year looks like. This is a tiny fuel cell chip, just 3mm x 3mm in size:
I know that many people are concerned about sea level rise over the next century. In the rate of 3 mm per year continues, we’d be at 300 mm (30 centimeters) of rise in 100 years. Here is what 30.48 cm (12 inches) looks like:
And finally, here is what the tide gauge at Anchorage Alaska looks like:
Anchorage Alaska boasts the world’s second highest tides: varying over 40 feet (1219 cm), low to high tide. Ok, that is an extreme example, how about this one in France:
Mt. St. Michel on the north coast of France at low tide (left) and high tide (right).
The water surrounding this island is the Gulf of Sant-Malo.
Low tide
The point I’m making is that in 100 years, for some places that extra foot won’t make much of a difference. Some low lying areas will be affected certainly, but even some of the lowest lying areas of the earth won’t see all that much impact from a third of a meter of sea level rise in 100 years. Probably the worst place to live is in a river delta which is almost at sea level anyway. Even so, 30 cm falls short of the lowest notch on this graph of 1 meter.
Bangladesh is another low lying river delta where it is not desirable to live, yet many do. Even so it appears much of it is 1 meter or more above sea level.
Florida is often talked about as being at risk. yes there are a few places there that might be touched by a 30 cm rise in sea level 100 years from now.
Looking at the whole world, at the rate we are going, I’d say it will take awhile.
xiphoidprogress,
I’m sure that WUWT will give back its “Best Science” site award — just as soon as the charlatan Al Gore gives back his mistakenly awarded Nobel. Fair enough?
You claim that “When the Antarctic ice melts… the ocean levels are going to increase at a must [sic] higher rate than a few millimeters a year.”
Have you considered the fact that Antarctic ice is currently at about –50° F.? And that current “global warming” predictions are in the range of 0.6 ° F? It seems that we have a long way to go, in order to change frozen ice into liquid water.
Please explain how your putative global warming will cause –50° ice to suddenly change state, and become water. Where will the heat come from? As a scientist, I would be very interested in that mechanism.
Not all coastal erosion is due to sea level rise. These houses were several fields away from the edge when they were built, but this bit of the Isle of Wight has been crumbling away for some time, taking houses, roads, hotels, a naturist camp and bits of a local theme park with it.
We lose about 10 feet a year, on average, but it tends to fall away in chunks after heavy rainfall has penetrated down to a layer of Gault clay, known locally (and aptly) as ‘blue slipper’. Geology 1, AGW 0.
http://farm4.static.flickr.com/3363/3423839400_37e8c53d93_o.jpg
Smokey,
The Al Gore obsession around here is a little weird?
Not all of Antarctic ice is -50ºF. Much of the edge gets within several degrees of zero in summer, as mapped here. The Antarctic peninsular is of particular concern.
Glaciers flow in spite of the temperature of ice within them being below zero.
There are concerns that as coastal ice sheets break up the glaciers flowing into them will accelerate (as explained here). And research is suggesting that surface melt on the fringes of Iceland and Antarctica is flow down through cracks called moulins, lubricating the base of glaciers and thereby accelerating them.
“Ken Gregory (21:03:59) :
Satellite altimetry Topex/Poseidon/Jason data is ADJUSTED by the University of Colorado for NASA to match the rate of sea level rise measured by a set of 64 tide gauges. Any difference between the raw satellite measurement and the tide gauge measurement is ASSUMED to be the sum of satellite measurement drift error and the vertical land movement at the tide gauge location. A separate ESTIMATE of vertical land movement is made to determine the altimetric drift. This measurement drift as determined by the set of tide gauges is applied to the raw satellite data to create the adjusted satellite data.”
So, before the Antarctic [continent] moved to where it is, straddling the south pole [40MYA?] sea levels must have been much higher than today.
How come life survived? Ahhh, I get it, the creationists in the AGW movement must believe that Noah’s Ark is a real story.
If I put icecubes in a glass and they melt, the glass doesnt run over, but if I throw a rock in there it will over flow. Could some of the rise in sea level in some areas be due to ‘island building’ undersea? How much does that new material displace water? I hear that volcano near Tonga is building a new island.
http://www.reflector.com/news/world/strong-quake-near-tonga-prompts-tsunami-warning-498835.html
Its done it before….
http://earthobservatory.nasa.gov/IOTD/view.php?id=7126
So while were worrying about melting ice raising our water levels, has anyone considered how much water must be displaced by a volcano that rises from the ocean floor to the surface? Tonga, Hawaii, Im sure there are others..
@ur momisugly pkatt (06:52:18) :
As new material is being added, older material is being taken away.
Check out this image of sea mounts being caught up in subduction zones.
http://www.geology.um.maine.edu/geodynamics/analogwebsite/UndergradProjects2005/Laracy/graphics/cocos3.gif
and
http://www.geophysik.uni-kiel.de/~geo43/images/sfb5.jpg
Craig Allen reminds me of the kid in that old parade joke making the rounds among the military when I was in boot camp back in the ’60’s: “Look, Mommy, everyone is out of step but Daddy!” The best evidence available shows that changes in the sea level are entirely natural. The sea level is nothing to be concerned about.
Glaciers flow due to precipitation at higher altitudes. Temperature has almost nothing to do with it. And CO2 has nothing whatever to do with it. Glaciers flow in spite of the temperature of ice within them being below zero, because of the plasticity of ice.
Check out these pics of the mean sea level in 1841: click There is absolutely nothing to worry about WRT the sea level.
[And please, for the sake of honesty if nothing else, don’t link to Realclimate here. They are not credible. They are losers. They censor polite comments made by knowledgeable posters, when those comments contradict their AGW/CO2 agenda. And they are financially supported by George Soros. More reasons on request.]
I’m surprised than no one (especially those of you with a geology background) has raised this issue of subsidence here. Specifically geologic subsidence. This is reality with a good part of the gulf (US) coast off the Mississippi river delta. Some have said (no cites, too lazy) that it is a result of pumping out all that “awl” out of the ground. Not true says one geology PhD at LSU who says it has more to do with sediment loading from the river emptying into the gulf (google it, I’m too lazy yet again). Regardless, the gulf coast *is* sinking which of course contributes to the apparent rise in sea levels in these parts. And over geologic time scales, the barrier islands (see Galveston) are nothing.
And finally, DJ – you do little to enlighten or advance your case. Why post here? It’s not like you have anything to add.
” Jared (03:48:08) wrote:
In the 2004 graph, the 2003 peak is higher than the 2004 peak.
In the 2005 graph, the 2003 peak is higher than the 2004 peak.
In the 2006 graph, the 2003 peak is now a little lower than the 2004 peak.
In the 2007 graph, the 2003 peak is well below the 2004 peak.
In the 2008 graph, the 2003 peak went back to being higher than the 2004 peak.
In the 2009 graph, the 2003 peak once again became lower than the 2004 peak.”
There are actually 3 graphs. Not just the 2003 peak changes, every peak and valley is different. Even the loose points hovering around the 60-day smoothing line are different. This is obvious when you look at the shape of the 1998 peak and the loose points above it.
2004: graph a – the 1998 peak is sharp
2005: graph a
2006: graph b – 1998 not so sharp anymore
2007: graph c – 1998 not sharp at all
2008: graph a again(!) – 1998 is sharp again
2009-1: graph c is back
2009-2: graph c
-This graph has been completely redesigned\recalculated twice – once in 2006 and again in 2007. Does anyone know how that has been done?
-It is peculiar that graph a comes back in 2008. What could be the reason?
Anthony, thank you for this great blog, on which I have been spending way to much time. It’s very good for my serenity of mind though.
Robin I can’t understand the data at all. It seems to be manipulated to achieve a desired effect. The starting point for 60 day smoothing has shifted from -14 in the ’04 graph to -26 in the 2009 graph.This would give a consistent upward trend to the smoothing line.
However, the graph for 2006 seems totally inconsistent with the others. What is actually happening?
Chuck near Houston (12:40:24) said:
“I’m surprised than no one (especially those of you with a geology background) has raised this issue of subsidence here.”
Chuck you may have missed my post at (21:18:59).
More than just subsidence due to sediment loading, is isostatic adjustment of oceanic crust as it cools down. Cooler things are more dense, and as oceanic crust cools and moves away from the spreading axis, it cools down, becomes more dense and “sinks” lower in the mantle.
So we have some crust sinking due to sediment loading, other sinking because of isostasy, and some crust (continental) rising due to isostatic rebound that has been occurring since the glaciers melt.
The whole deal makes for an interesting mess when trying to measure rates of change with respect to sea level.
I think some of the changes in the graph are the result of an error which was discovered last Summer in the processing algorithms for Jason-1 sea level when they were calibrating the new Jason-2 satellite.
This reduced Jason-1 ‘s sea level trend from 3.3 mms per year to 2.4 mms per year and the old years were restated.
What is very interesting is that the Jason-2 calibrations were completed early in the Fall and operation of the satellite was turned over to JPL.
But, no data has been released from Jason-2 yet.
Ken Gregory,
OK, I have to ask – what satellite measurement drift? As far as I know there is none, and it would not be linear. There is no drift in the position or timing (GPS based with RF link radiometric measurements used to provide independent tracking).
I would have to look at the payload designs again but there is no ‘drift’ in their performance.
Will check your link but that sounds like a lot of CU BS to me.
AJStrata
Keep flapping them gums Smokey. The more you say the less sense you make.
I’m not sure how providing a photo of the Port Arthur historic sea level mark without any context helps you. But if others are interested, here is an explanation of its relevance. Remember it is a single location, and so can’t be considered a proxy for the entire ocean.
You first said that because the temperature in Antarctica is below 50ºF a few degrees warming can in no way affect the ice. Then, when I demonstrated that that is a misleading assertion, you said that temperature doesn’t affect glacier flow. Interesting theory; I suggest you do a little more reading on that.
Here’s a puzzle. If, as you suggest, the predicted warming can not possibly cause significant melting of our ice-caps. How is it that the ice-cap covering a very substantial portion of North America during the last ice age to a depth of several kilometres, melted away with a global increase in average temperature of just 7 or so degrees?
Here is an article from NASA that you may be interested to read Snowmelt In Antarctica Creeping Inland, Based On 20 Year Of NASA Data
I’m sorry if the RealClimate people hurt your feelings. I’ve observed that they welcomes skeptical posters, but get cranky if writers don’t make sense, try to misrepresent data, are abusive, use dodgy rhetorical tricks to advance their case, or refuse advance their understanding of the science. They do the same if folks who believe global warming is real try the same tactic. Scientists are very strict on people talking gobbldegook.
In my last post I of course meant to “below -50ºF“. Sorry to misquote you Smoky.
“ian George (15:12:51) wrote:
Robin I can’t understand the data at all. It seems to be manipulated to achieve a desired effect. The starting point for 60 day smoothing has shifted from -14 in the ‘04 graph to -26 in the 2009 graph.This would give a consistent upward trend to the smoothing line.
However, the graph for 2006 seems totally inconsistent with the others. What is actually happening?”
Ian, the zero has been moved 3 times on the vertical axis.
2004 60-day smoothing starts at -14
2005 60-day smoothing starts at -14
2006 0 goes 12 units down, 60-day smoothing line starts at -2
2007 0 goes 30 units up, 60-day smoothing line starts at -32
2008 0 goes another 6 units down again, smoothing line starts at -26
2009-1 smoothing line starts at -26
2009-2 smoothing line starts at -26
But that doesn’t change the shape of the graph. As you can see when you compare graph 2004 and 2005 with graph 2008. Exactly the same graph with the zero in a different place.
Of course the 2008 graph is horizontally compressed to get more years in the same space, but it is easy to see that it is the same graph as 2004 and 2005.
Now compare graph 2008 with the 2 graphs of 2009.
The zero is in exactly the same place, the 60-day smoothing line starts in all graphs with -26, but the graphs themselves are very different.
And it’s not just some recalculation of the smoothing line, because the individual measures points that hover around the smoothing line are also in differently positions.
They have changed\corrected the measurements.
Why?!
And the weirdest thing: they had already done that in 2007. Compare the 2007 graph with 2009 and you’ll see that it’s identical.
Then why in 2008 did they go back to the 20004/5 graph?
Not to mention that the 2006 graph is different in shape from all the others.
“Bill Illis (16:23:48) wrote:
I think some of the changes in the graph are the result of an error which was discovered last Summer in the processing algorithms for Jason-1 sea level when they were calibrating the new Jason-2 satellite.
This reduced Jason-1 ’s sea level trend from 3.3 mms per year to 2.4 mms per year and the old years were restated.”
Bill, the first recalculate graph appears in 2006, the next one in 2007.
So that can’t be what you mention.
I see no obvious differences in the 2008 and 2009 graphs, just 2 measurements in 2002 that have been retroactively corrected.
I’d love to see the corrected graph. If the trend goes down from 3.3 to 2.4 mm/year, that must might the sea level has been decreasing a bit.
… that might mean sea level has been decreasing a bit.
Craig Allen offers an interesting question:
Are you suggesting that we are facing a further 7 or so degrees rise in average global temperatures because of human produced CO2? If so, over what time frame?
If not, what temperature rise are you suggesting will occur because of human produced CO2 and over what timeframe, and what sea-level rise will that cause? What other effects will it have? Please be explicit.
Further, what will it cost to mitigate those problems by reducing CO2 production? What probability do you place on the proposed mitigation actually doing anything usefull? What cost do you place on mitigating the problems using other approaches, like moving people?
“I’m sorry if the RealClimate people hurt your feelings. I’ve observed that they welcomes skeptical posters, but get cranky if writers don’t make sense, try to misrepresent data, are abusive, use dodgy rhetorical tricks to advance their case, or refuse advance their understanding of the science. ”
Fatuous nonsense. No one here cares, we’re overweighted with engineers with virtual or actual minors in math and physics. Only trolls provide links to RC and beg us to visit and mourn Gaia’s defilement.
Richard Sharpe:
Reread my post. I clearly did not say that we are facing “7 or so degrees rise in average global temperatures because of human produced CO2”.
I’m not sure about the latest models, but the IPCC’s AR4 report [beware that’s a big pdf file) concluded that climate scientists believe that if we let greenhouse gasses rise to 1000ppm (in CO2 equivalents) we would face somewhere between 3.5 and 8 degrees rise by the time the climate equilibrium was reached. I hope humanity isn’t that suicidal. They concluded that if we continue on a business as usual emissions scenario we are likely to get between 2.3 and 4.8ºC warming between 2000 and 2100 with 3ºC being the most likely.
Smokey:
Mate, a straw-man doesn’t compensate for a logically flawed statement. The climate is naturally variable. No one has ever disputed that. We are taking a variable system and forcing it toward a state it is very unlikely to have otherwise have reached and at a far faster rate than is otherwise plausible.
Gary Gulrud,
The various economic analyses I’ve seen suggest that reducing CO2 emissions significantly will have a modest affect on the growth rate of economies, and may even boost them. It’ll certainly be a lot cheaper than wars and unrestrained financial scullduggery. The costs (in both financial and human suffering terms) of adapting to the predicted consequences of our current emissions path are otherwise going to be unimaginably huge.
“It’ll certainly be a lot cheaper than wars and unrestrained financial scullduggery. ”
Envirofanaticism pursued by intellectual lightweights who remain politically powerful can easily bankrupt or starve billions to no good purpose.
For example, have your studies into the decrease in C13:C12 fraction considered the man-induced loss of billions of tons of naturally sequestered CO2 over the past century or two to soil erosion?
Have they considered the deleterious effect of an increased world price of corn, increased nitrogen pollution of river deltas, increased aldehyde pollution of urban air, increased fuel consumption following decreased mileage creating world recession and financial failure, of increased potable water use and exhausted aquifers, and decreased resources via failure of ethanol plant closures in the enviornmentally friendly pursuit of biofuels?
Your much.too.lame.to.read illiterati at RC are dangerous, not well intentioned and reasonable. Return to your ‘dog’s breakfast’.
Below is a link to a live presentation on sea level rise preparation and consequences in California. This was presented on April 9, 2009 at the California Coastal Commission hearing in Oxnard, CA.
Scroll down to Item 3, and click on the film reel icon next to Sea Level Rise Workshop.
http://www.cal-span.org/cgi-bin/archive.php?owner=CCC&date=2009-04-09
While researching and preparing my comments for EPA’s “CO2 is harmful to humans proposed finding”, I came across this interesting graph and article from NASA’s Goddard Institute for Space Studies (GISS).
http://www.giss.nasa.gov/research/briefs/gornitz_09/
The graph shows sea level rise of 120 meters over 18,000 years since the last ice age. The increase was not uniform, but had at least three meltwater pulses (MWP), and possible four, that led to rapid sea level rise.
The interesting point of this graph is that the rate of sea level rise has decreased dramatically in the past 5000 years, rising only 5 meters in that time. The rate of rise is only 1 mm per year.
The takeaway from the graph and accompanying text is that human influence was zero during that entire 23,000 year period, except for the past 150 years at the most. Yet, sea level rose rapidly at times, and held almost constant at times. The concept that humans have any impact at all on polar ice melting, and sea level rise, is ludicrous. Other forces are clearly at work, and their effects are overwhelming when compared to human activity.