(Part of the How to Talk to a Global Warming Skeptic guide)
Objection: According to the latest state-of-the-art satellite measurements from over the Arctic, sea levels are falling! Guess all that ice isn't melting after all.
Answer: Yes, a new study using Europe's Space Agency's ERS-2 satellite has determined that over the last 10 years, sea level in the Arctic Ocean has been falling at an average rate of about 2 mm/year. This is very new and very interesting news, though it is preliminary and not published in any peer-reviewed journals yet. But even if these results hold up to time and scrutiny, it is not evidence that globally sea levels are not rising, because they are.
(courtesy of Global Warming Art)
Sea level and sea level change is not uniform around the globe.
Local sea levels are subject to many influences including: wind and ocean currents that can "pile up" the ocean water locally, temperature anomalies like El Niño, local gravity wells of ice sheets and land masses, and regional salinity levels that alter the water's density. Measurement of these levels is further complicated by changes in land height as the Earth's crust moves up or down from tectonic motion and rebounds after long and recently ended glaciation, although these complications are avoided by using satellite measurements.
So in short, this is undoubtedly of interest to specialists in several fields, but it does not in any way alter the Global Climate Change picture.
Real Climate has a more detailed writeup on this here.
Skeptics claim global warming is fake after top scientists’ emails hacked at CRU
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Zarkov Posted 3:31 pm
10 Nov 2006
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Coby Beck Posted 6:54 am
11 Nov 2006
Invent a clever saying, and your name will live forever!
-- Anonymous
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lgl Posted 2:47 am
23 Feb 2007
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Coby Beck Posted 7:44 pm
06 Apr 2007
A couple of possible factors come to mind. Firstly is that the simple fact of slower response times would smooth over the more up and down global mean curve. Observed sea level rise is primarily thermal expansion and icesheet/glacial melt, both more ponderous processes. Secondly, if you look at N hemisphere vs S. hemisphere 20th century trends you will actually see that the S hemisphere did not ever show any prolonged cooling, rather more of a brief spike and return to gradual warming. See here:
http://hadobs.metoffice.com/hadcrut3/diagnostics/hemisphe ...
I point this out because the majority of the earth's oceans are in the southern hemisphere. This differing behaviour is also consistent with the fact that globally aerosol pollutions are more prevelant in the north.
"What if this weren't a hypothetical question?"
-- unknown
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Delay And Deny Posted 2:34 am
07 Apr 2007
Clearly oceans will recede as ice melts and the earth crust expands due to heating. Heat expands things.
Also, the caverns under the earth will open up and take in more of the sea water. A huge underground sea has already been discovered in China.
My model predicts this precipitous drop in ocean levels confirmed by the Arctic.
The Texeme Construct offers international text memetics construction and textcasting services. http://www.you-read-it-here-first.com
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tico89 Posted 3:17 am
07 Apr 2007
Seriously, though, isn't this a bit like the 'it's cold today in __' one? It's the overall picture you have to look at.
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GreyFlcn Posted 5:26 am
07 Apr 2007
But I have heard that in Alaska, the issue is not so much that the sea level has been changing.
It's that the land underneath the ice is decompressing as the ice melts off.
_
Not sure if this is the case in this discussion.
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mrick Posted 1:23 pm
10 Apr 2007
Could the rise as shown in the graph be the result of the erosion of the earth's land masses into the oceans? What is the volume of mud that streams into the oceans from all of the great rivers like the Mississippi, Nile etc. and isn't that going to displace water at a 1 to 1 ratio? Add in all of the beach erosion from wave action and wind erosion - which all should be fairly steady over time or more likely increasing due to human developments - and perhaps causing ocean levels to rise at a steady to increasing rate.
I can't think of any forces that work in reverse by depositing eroded material flushed into the oceans back onto the land. Only plate tectonics can do this but I would think plates around the world are both sinking and rising and thereby offsetting each other.
Just a thought.
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Coby Beck Posted 12:04 pm
12 Apr 2007
Without doing any measurements, I would think a step back and bit of thought would put this into perspective.
Erosion is not new, (despite the books for sale at the Grand Canyon gift shop) so if erosion were outpacing tectonic activity wouldn't we already have a pretty flat and worn down land surface?
Sea level has fallen and come back up by over 100 metres many times over the last million years and was even 150 metres higher than it is today 10's of millions of years ago. Unless you have a reason to believe land has eroded and reformed this quickly it would seem this is not a significant factor in past sea level changes.
And if this is to explain current trends (which already have a very well supported explanation btw) you need to demonstrate some major change having occured.
"What if this weren't a hypothetical question?"
-- unknown
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MF Posted 10:38 am
16 Jan 2008
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Delay And Deny Posted 10:48 am
16 Jan 2008
What a nice chart...it's called "Climate Art" as it is a work of fiction. If you follow the links to its origins it says that it's based on PSMSL data.
I followed the links and I got to a page like this:
http://www.pol.ac.uk/psmsl/psmsl_individual_stations.html ...
Tons of individual monitoring stations. So, where is the data that was actually used to paint those summary data points? I suppose I will have to look at each of these stations to see if someone is cooking the books.
I've already presented data from NOAA showing that there are more low tide anomalies than high tide anomalies around the US coast.
My Log
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