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.
Florida is practically a pile of seashells. Living there, several miles inland from the coast, and well above the category 5 surge line, I dug postholes for a fence in the back yard, and it seemed to me the soil was a pile of loose ocean debris. The inland waterways there are a great place to find fossils of sea life.
So, a few degrees of warming, and coastlines will be a tad smaller? Isn’t an ice age just 14 degrees colder? Read that somewhere. So, what do we lose with another little ice age? I’m moving back to Florida.
Holgate determined that 70% of the sea level rise of the 20th century was due to thermal expansion of the oceans and the balance due to melting glaciers etc. The 20th century had an increase of sea level the same as that prognosed for the 21st century, but hundreds of millions of people weren’t displaced and beachfront property remains very popular. Therefore a continuation of the current trend would not be alarming at all.
Anymore on Dr Morner’s somewhat incendary views on sea level rise?
http://www.mitosyfraudes.org/Calen7/MornerEng.html
The Ganges/Brahmaputra delta is being affected by upstream errosion, caused by deforestation, leading to more mud being brought down river and an increase in flooding.
The entire delta is changing on an annual basis, existing land being eroded by the monsoon floods, the same floods depositing new land, so the inhabitants move frequently.
Good job there isn’t a borderline running down the middle of the delta, the arguments over which country owns these ephemeral islands would be continual.
http://www.statesman.com/blogs/content/shared-gen/blogs/austin/weather/entries/2009/04/07/record_lows_thi.html
All time record low for Austin TX
“I don’t believe that the parameters of the satellite orbit are known to within millimeters.”
Sid hits the nail square on the head. If we can’t tell whether two satellites are going to collide or pass 1,000m apart then the error bars on these graphs should be measured in meters. Which makes them nothing more than ‘art’.
IF the second quote from Dr. Mörner is correct, that sea level rise has not been more than “… 1.1 mm per year”, what has the real trend been since 2004?
Mike
The CU data can be accessed at their website; if anyone wants to play around with it in Excel…
http://sealevel.colorado.edu/results.php
I haven’t
The Proudman Oceanographic Laboratory has some very good sea level data bases too. Jevrejeva (2008) built a post-1700 sea level reconstruction, corrected for local datum changes and glacial isostatic adjustment.
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What about this analysis, that argues against historic sea-level rises (last 100 years or so).
http://www.john-daly.com/ges/msl-rept.htm
Any flaws in what is argued here?
If you download the “Inverted barometer not applied, Seasonal signal removed” data file and apply a 10-year moving average; the rate of sea level rise has clearly begun to level off since 2005.
Don’t see what the fuss is all about. How much has sea level risen in the last 200-500 years? Was there mass panic? No. if your feet get wet move.
It is ironic that the University of Colorado is the authority on sea levels, given the program’s location in the Rocky Mountains.
I, of course, understand that some very smart people teach and study there.
My most recent post happens to be on the topic of sea level alarmism:
http://www.talkingabouttheweather.com
Harold
>>On a more serious note, what is the height relative to?
>>Could it not equally be the land mass sinking..?
Yes, very much so. As this report makes clear, all of the sea levels in Scandinavia are measurably falling, because Scandinavia is rising. Thus the measurements have to be ‘rebased’. But since this rising of the continent is tricky to measure, there is a lot of guesswork.
So yes, against what yardstick are we measuring sea-level rise?
http://www.john-daly.com/ges/msl-rept.htm
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The projections don’t appear to consider the possibility of future moderation in sea level rise. If the oceans cool, the water will contract. The NOAA station data along the Pacific Coast show a general peak at around 1998, with slightly lower readings in the past five years. This may reflect the warmer ocean in 1998 and the cooler ocean since then. Dr. Willis, of JPL, found the Pacific had not warmed over the previous four years, with minimal if any increase in sea level over that period.
In Singer’s book “Unstoppable (Every 1,500 Years) Global Warming”, in his chapter on rising sea levels he states that the most likely sea level rise this century will be about 10 -15 cm (4 – 6 inches), the same rate of increase as in recent centuries, and that melting at the poles is offset by increased humidity and snowfall, adding further ice.
INQUA’s (International Union for Quaternary Research) Commission on Sea Level Changes and Coastal Evolution forecast of “seal level” (yes, the typo is right there in the book) rise is “10 cm – plus or minus 10 cm”.
Alarmists LOVE to exaggerate predicted sea level rise, and consequent damage from that. Most coastal damage though, is from sheer stupidity. Of course, what they miss entirely is the fact that sea level rise, like warming is just about 100% natural.
It seems as if the rate has flattened since JASON (2.3 mm/yr) replaced TOPEX (3.2 mm/yr). The present flat spot seems similar to the 1998-2000 time frame so I wouldn’t make any assumptions right yet about the rise stopping.
Everybody save articles like this for future reference.
http://www.reuters.com/article/domesticNews/idUSTRE5363D320090407
All I can say is “oh well”. We apparently haven’t learned from history that coastal areas always have been and always will be vulnerable to any number of issues, but slow sea level rise is the least of their worries.
But again, we’re taking an incredibly small snapshot in time and calling it a catastrophe. It’s tantamount to taking measurements of rainfall over a 10 minute time period and declaring a worldwide flood from rainfall because the rate increased 10 fold in 10 minutes.
Insanity.
If the continents move at 4cm/yr and the MSL is only increasing by 2mm/yr, why can’t this change in MSL be attributed to a change in sea basin geometry.
Given all the eschatology that the AGWers are purveying I can finally understand why it was such a powerful force for the early Christians.
Dave,
Does that data also remove the “shifting zero” that Katherine brought up?
Just as an example, looking at 2006, its values are: 35, 33, 33, 26, 55. WUWT??? Like the temperature data, I would assume one should set a zero and stick to that standard in all subsequent runs, otherwise how can a time trend be detected.
NASA says Arctic sea ice is thinning
http://news.cnet.com/8301-11128_3-10213891-54.html
The 2009 Arctic summer melting season is starting out with a substantial amount of thin seasonal ice and an unusually small amount of the thick sea ice, making it more vulnerable to melting, according to the NSIDC’s report.
The older, thicker sea ice is declining and is being replaced with newer, thinner ice that is more vulnerable to summer melt,” Kwok said in a statement.
“With these new data on both the area and thickness of Arctic sea ice, we will be able to better understand the sensitivity and vulnerability of the ice cover to changes in climate,” he said.
One thing I could not help but notice is that 2006 R3 shows an increase of 45 mm, while all the other releases show 20-25 mm. From 2004 to 2008 the line is flattening at 20-25 mm. Clearly someone had some data problems there.
And one has to take into account the increased accuracy of the global measurements achievable by TOPEX/Poseidon and Jason. These two missions employed differential GPS that allowed accuracies of 10’s of CMs in surface measurements. Before that the error bars must have been in the meters range. If you look at the period for these two missions it is +/- 20 mm, well within the error bars for differential GPS from LOE considering the tidal situations you illustrated so well.
If one takes the limits of differential GPS from LOE into account, then the changes form 1960 to 2008 shown in the New Zealand graph could all be due to simply having better measurements – no appreciable increases may have occurred during this period.
Trying to say there are 20-25 mm’s difference in a measurement whose accuracy I doubt is below 10 cm’s seems to be a stretch.
FYI – I am doing this all from memory from my work at NASA reviewing applications of GPS to NASA programs from the mid 1990’s. If someone has actual references that would be interesting to see.
Cheers, AJStrata
Gary Pearce notes:
The primary cause of delta fatalities are cyclones (hurricanes) and water born diseases.
The April 1991 Bangladesh Cyclone killed 138,000 people. Packing 255 km/h (158 mph) winds, the cyclone brought drove ashore a storm surge estimated at between 6 m (20 ft) and 9 m (30 ft). Many deaths were attributed to a lack of cyclone shelters. See Risk factors for mortality in the 1991 Bangladesh Cyclone C. Bern et al. Bull. World Health Organization, V.71, pp 73-78 (1993)
Their survey suggested that those who reached shelters survived, while deaths were primarily among women and children below 10 who did not reach cyclone shelters.
See: The Bangladesh Cyclone of 1991: Why So Many People Died
A. Mushtaque R. Chowdhury 1 , Abbas U. Bhuyia 2 , A. Yusuf Choudhury 3 Rita Sen 4 (1993) Disasters Vol. 17 #4, pp 291 – 304, 18 Dec 2007
ABSTRACT
Even after shelter construction following with 1970 and 1985 cyclones, there were only 311 shelters with a capacity for 350,000 persons.
Adaptation will be far more cost effective to build 100,000 storm shelters at $10,000 each (for $1 billion) than to pay $45 trillion trying to control climate with dubious results.
Ocean rise of 3mm/year is negligible compared to 6,000 mm to 9,000 mm storm surges.
OK, stopped being lazy and did a quick search and noticed that the TOPEX altitude can only be determined via differential GPS to 5-8 cm, which means the measurement of sea surface is probably in the 10 cm range. There is no statistical basis for +/- 25 mm shown in the chart. It would seem to me this is statistically zero rise in sea level.
OT, pretty much, but Walt Meier is at is again. Arctic will be ice-free within a decade. Or not.