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.
Forgot the link: http://www.agu.org/pubs/crossref/1992…/91JB02562.shtml
Re:
DJ: If wave action is eroding sand in one location, it will be doubtless be busily creating a new beach somewhere else. The location of the second beach may be quite inconvenient to the inhabitants of the first. I don’t know if this is a law of nature, or one coined by Murphy. : – )
WRT
It seems that some people will always try to live too close to the sea, too close to volcanoes, too close to earthquake faults. Your picture of Tuvalu illustrates this if nothing else. From what I can gather on Wiki about these tropical atols, (your island?) looks, as they say, like a beautiful place to visit, but…
The question of whom they will sue when they are threatened by the sea is certainly of some pressing urgency to them.
As for:
I have no doubt about that. Another law which seems to have gained ascendancy among scientists and victims-in-waiting of nature these days: “The squeaky wheel gets the grease.”
“3mm rise per year will lead to an average coastal recession of 3cm to 30cm per year for sandy beaches – that puts places like Florida in line for more than 100 feet of coastal recession this century with a low end sea level rise.”
Maybe the sea levels will rise as high as they did during the last interglacial (I believe some 6 to 8 meters higher than they are now).
Sid Brooks,
TOPEX and Jason use differential GPS to determine the altitude of the satellite to within tens of cm. This is a post pass process that combines the GPS position measured on board to extremely well surveyed stations on the ground (TOPEX used NASA’s Deep Space Network stations). The fact the station locations are known to extreme accuracies allows the satellite position to be refined over many ranging contacts.
Basically by triangulating the satellite to known fixed points on the earth, all using the same GPS time reference (within nanoseconds in many cases) then you can drive out the on-orbit errors in altitude. Many samples over the orbit drive out the orbital decay effects.
But you are right, there are limits and these data are seem to be well within the error bars.
AJStrata
Aron (06:29:59) :
“Everybody save articles like this for future reference…”
Thanks, Aron, but…for sure this year even small tropical storms will receive a “name”, otherwise it would mean to say that the “King is naked”, nobody would dare to do that.
speaking of storm surges….
Atlantic Hurricane Forecast Lowered
http://www.foxnews.com/story/0,2933,513002,00.html
Comparing these nanometer sized increases with continents which are RISING up, chances are, that nature will not please Gwrs.
“The Arctic Ridge has the slowest rate (less than 2.5 cm/yr), and the East Pacific Rise near Easter Island, in the South Pacific about 3,400 km west of Chile, has the fastest rate (more than 15 cm/yr).”
http://pubs.usgs.gov/gip/dynamic/dynamic.pdf
No, no, no… It cannot be possible that UC is taking a very small portion of a cycle rise of sea level like a signal of anthropogenic global warming or something unusual or atypical. As I’ve written in another WUWT thread, currently the mean sea level is going on a phase of regression, that is, within a longer phase of sea level declination. Normal small declinations and rises happen into the four phases on every cycle, which are not larger than one meter. Today, the MSL is on a phase of regression and it has not yet touched the bottom, i.e. the MSL has not yet reached the lowstand phase, from which it would begin a true and maintained rise of the sea level. Nevertheless, globally and in a long term scale, the trend is towards smaller flooded areas, which means that in some centuries ahead, once the phase of transgression is reinitiated, the area of flooded continents will not be larger than 12%.
It’s quite evident that this people’s agenda is to terrorize people with ominous anthropogenic disasters.
And the trend of AGWers is to produce Hockey Sticks everywhere… Hah!
http://upload.wikimedia.org/wikipedia/commons/4/44/Phanerozoic_Sea_Level.png
TOPEX/POSEIDON http://sealevel.jpl.nasa.gov/mission/tp-fact-sheet.html
– Sea-level measurement accuracy 4.2 cm (1.7 inch)
Jason-1 http://sealevel.jpl.nasa.gov/mission/jason-fact-sheet.html
– Sea-level measurement accuracy <4.2 cm (1.7 inch) required, <2.5 cm (1.0 inch) goal
So the measurement accuracy of the instruments on these satellites is an order of magnitude less than the changes they purport to measure. How does that work, exactly?
The highest resolution measurements of ocean level at specific locations appears to be from using quartz resonant pressure sensors. See:
High Accuracy Pressure Instrumentation for Underwater Applications Mark H. Houston and Jerome M. Paros, ParoScientific
Highly Stable Long-Term Measurements of Height Differences with Digiquartz Depth Sensors, Dr. Theo Schaad, Paroscientific Inc. Technical Note G8072 Rev. A, 13 April 2006
Nano-Resolution Oceanic, Atmospheric, and Seismic Sensors With Parts-Per-Billion Resolution, Dr. Theo P. Schaad, Paroscientific, Inc. Technical Note
Doc. No. G8218 Rev. E, 10 March 2009
The long term “accuracy” is claimed to be about 100 ppm.
Can or have the satellites be calibrated against ocean patches with an array of such pressure sensors?
If we look at the rowboat moored alongside the historic Alaska Tide Gauge in the ‘low tide’ image, the red painted line (well, what maybe would be red, if this was a colour pic) stands at probably about 300 mm above the water level. So this is the amount by which sea level may rise over the next century. This truly throws into perspective the garbage which is being spoken about life on the planet being irrevocably altered by rising sea levels. (New York being abandoned, and so on! What hogwash, as so ably demonstrated by Anthony)!
Geoff Alder
AJStrata,
Thanks for those eye-opening observations. Are the numbers for Jason similar?
Mike Bryant
This post isn’t science. More politics, or how sea level rise affects the debate at the average guy level. I think I can offer insight into that.
I look at that graph at the top. I see flattening from 2006 with my unscientific eyes. No biggie. I see 3 years of flattening from 93, or 98 as well. In fact that appears to be the pattern in the 16 years offered. 2 to 3 years of flattening then a spike.
If I’m looking at that graph in 2010 and it’s still flattening I’ll notice it, but it won’t affect my opinion.
However suppose the American election year of 2012 comes around and not only is sea level rise still flattening, but it’s made the teensy weensy dip to 2004 level. The world conferences on climate have come and gone. Decisions have been made to apply pressures which have filtered down to me, and my average joe compatriots. Taxes are higher. Energy is more expensive, and less reliable. Other problems we didn’t even expect have surfaced. At that point I look at that graph in 2012. I see no sea level rise in 8 years, and now I’m pissed. In my average guy brain, I finally, fully get how bad I’ve been swindled.
I agree with Sid, Masonmart, and others, that IMHO, we know mean sea level to the degree of accuracy published is very unlikely. The same with temps. I see many graphs, extending back for 100 plus years, with an implied accuracy of .001 degrees. Seems unlikely to me. Like looking at stock charts with a microscope. UAH mid-troposphere temps. peaked in 4/1998 and bottomed in 1/2000. Neither extreme has been breached for many years now. ISTM that there can not be a “trend”, without a new high/low. fm
I thought AGWrs. in some point would change their speech and turn it to a more general “climate change”, but it seems they are totally convinced of global warming. Somebody let the King know that he is really naked!
Dear David L. Hagen (07:32:01),
Nice post and as a follow up I’d like to add some more recent information from Bangladesh.
I was in Bangladesh just after cyclone Sidr in 2007 and although I don’t know the intensity in relation to the 1991 event, the number of deaths was only around 5,000 due to the building of shelters and early warnings. The death of 5,000 people is tragic, but even in a country as poor as Bangladesh the ability to protect their inhabitants has been vastly improved by development in the intervening years.
I know many people working in development in Bangladesh and they are all being thrown into panic by the claims of metres of seal level rise, forgetting that they have coped with rising sea levels, and a growing population, and still developed their country enormously over the last 30-odd years since independence.
I just wish those alarmist commentators who insist we should hamstring our development “in case the worst case scenarios turn out to be true” could understand what that really means to a developing country: If Bangladesh had limited its CO2 emissions by not building cyclone shelters tens of thousands would have died in 2007.
Sorry for the off-topic rant, but I get cheesed off when people don’t consider the impacts of climate change alarmism and tell you we should do things ‘just in case’.
Rob
One foot every on hundred years?
How will we ever be able to adapt to such a rapid rise?
Marcus:
But if, heavens forbid, all the people on this site are wrong….
Please show me, Marcus, how enacting the draconian reductions in fossil fuel energy use “cure”, allegedly required to prevent the allegedly disasterous GW “disease” effects, will themselves not instead most certainly produce massive disasters of their own – ill effects of the “cure” which are rather easily envisioned but have intentionally not been included in the ipcc’s Climate Change/Science “scientific” analysis of Climate Change, just as the obvious benefits to GW regardless of cause have not been included, or at least not anywhere near to the extent that GW’s adverse effects have been projected and even rather obsessively and neurotically disasterized.
[The ipcc’s efforts in these matters sound more like a massive Panic Attack, its proposed cure to which looks mostly like Suicide.]
Face it, Marcus. The ipcc, enc., is simply not doing real Science.
Oh, horrors! The sea is rising at 32 MILLION ÅNGSTROMS a year! Oh, the humidity! DJ’s old Bijou Theater will be under water! We’re all gonna drown! Well, those of us who can’t run faster than 32,000,000 Å/yr, anyway. But wait! Maybe it’s really the SKY is FALLING at 32,000,000 Å/yr….
Seems to me I see a hockey stick, where the rate of change goes to zero starting in 2005….
Hasn’t anyone taught these so called scientists what a “significant figure” means? The AGW crowd talk about 0.6 degree temp rise when the equipment isn’t calibrated to closer than +/- 2 degrees. A 3mm/year rise in sea level when the sea has tides… give me a break I very much doubt the ability to measure a dynamic land/sea area with this type of accuracy, especially with rebound, erosion and sedimentation. The land is a DYNAMIC system where land is eroded and lakes and seas get filled with sediment. Time to take GEO 101.
Any maps that show how the continents have shrunk since the Holocene sea rise began some 10,000 years ago? Might be good for people to see the large natural changes that have already taken place in our coastlines and land mass.
I would urge caution to the literal use of Bruun’s rule as some have suggested to determine beach loss as a result of increasing sea surface levels.
Any local projection of inundation must take into account geologic changes. New Jersey is a prime example where the land mass is sinking some 7 inches per century as the result of isostacy -glacial rebound. The City of London which is also routinely shown at risk has a very large component that is due to natural sinking of the land mass. Projections of sea rise that do not incorporate geological forces paint a very distorted picture.
Here is a link showing the UK and France were not split by the Channel, Ten Thousand years B.P. (before present). It shows England and France were part of a sweeping Boreal Forest and a large connected Temperate Forest.
http://www.walrus.com/~syrett/sy_res/sy_proj2.htm#NGDC
Perhaps there are more maps, showing the natural changes in coastlines, as the ongoing Holocene melted the Ice Age ice and oceans rose.
Mike Bryant,
TJ Overton grabbed the right numbers above and they are equivalent – Jason is attempting to gain more accuracy, but physics has its limits.
As I suspected the precision of the satellites is not down to the level of the mythical changes, Statistically these satellites show no increase.