Greenland rapidly rising as ice melt continues

May 18, 2010
Greenland rapidly rising as ice melt continues

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This is a satellite image of Western Greenland, acquired by NASA's MODIS satellite. The narrow grey band in the center of the image is melting ice, between the rocky coast to the left (west) and thicker, non-melting, higher altitude ice to the right (east). Small lakes form in this region during the summer. Arrow points to darker grey zone of rapidly thinning ice near the outlet of Jacobshavn glacier, which also loses mass due to iceberg calving. Credit: Courtesy of NASA

Greenland is situated in the Atlantic Ocean to the northeast of Canada. It has stunning fjords on its rocky coast formed by moving glaciers, and a dense icecap up to 2 km thick that covers much of the island--pressing down the land beneath and lowering its elevation. Now, scientists at the University of Miami say Greenland's ice is melting so quickly that the land underneath is rising at an accelerated pace.

According to the study, some are going up by nearly one inch per year and if current trends continue, that number could accelerate to as much as two inches per year by 2025, explains Tim Dixon, professor of geophysics at the University of Miami Rosenstiel School of Marine and Atmospheric Science (RSMAS) and principal investigator of the study.

"It's been known for several years that is contributing to the melting of Greenland's ice sheet," Dixon says. "What's surprising, and a bit worrisome, is that the ice is melting so fast that we can actually see the land uplift in response," he says. "Even more surprising, the rise seems to be accelerating, implying that melting is accelerating."

Dixon and his collaborators share their findings in a new study titled "Accelerating uplift in the North Atlantic region as an indicator of ice loss," The paper is now available as an advanced online publication, by Nature Geoscience. The idea behind the study is that if Greenland is losing its ice cover, the resulting loss of weight causes the rocky surface beneath to rise. The same process is affecting the islands of Iceland and Svalbard, which also have ice caps, explains Shimon Wdowinski, research associate professor in the University of Miami RSMAS, and co-author of the study.

"During ice ages and in times of ice accumulation, the ice suppresses the land," Wdowinski says. "When the ice melts, the land rebounds upwards," he says. "Our study is consistent with a number of global warming indicators, confirming that and are real and becoming significant."

Using specialized global positioning system (GPS) receivers stationed on the rocky shores of Greenland, the scientists looked at data from 1995 onward. The raw GPS data were analyzed for high accuracy position information, as well as the vertical velocity and acceleration of each GPS site.

The measurements are restricted to places where rock is exposed, limiting the study to coastal areas. However, previous data indicate that ice in Greenland's interior is in approximate balance: yearly losses from ice melting and flowing toward the coast are balanced by new snow accumulation, which gradually turns to ice. Most ice loss occurs at the warmer coast, by melting and iceberg calving and where the GPS data are most sensitive to changes. In western Greenland, the uplift seems to have started in the late 1990's.

Melting of Greenland's ice contributes to global sea level rise. If the acceleration of uplift and the implied acceleration of melting continue, Greenland could soon become the largest contributor to global sea level rise, explains Yan Jiang, Ph.D. candidate at the University of Miami RSMAS and co-author of the study.

"Greenland's ice melt is very important because it has a big impact on global sea level rise," Jiang says. "We hope that our work reaches the general public and that this information is considered by policy makers."

This work was supported by the National Science Foundation and NASA. The team plans to continue its studies, looking at additional GPS stations in sensitive coastal areas, where is believed to be highest.

Provided by University of Miami (news : web)

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eachus
May 18, 2010

Rank: 1.7 / 5 (17)
What a bunch of global warming propaganda. I'm sure they are right that parts of Greenland are rising, and that it is due to the melting of ice. The problem is that areas of Europe with no current ice cover are rising at comparable rates. See http://en.wikiped..._rebound for an explanation.

Is it possible that the Greenland rise is partially due to recent warming? Sure. But as anyone who passed Calculus will understand, the current rate of land rise integrates changes in ice levels over the past 10 to 20 thousand years. If the average in Europe is currently 11 mm/year, then 25 mm/year could be an outlier, but is probably due to the melting of "recent" ice buildup in Greenland during the Younger Dryas and Little Ice Age.

Oh, and notice the main effect of raising land levels in areas covered by ice during recent ice ages. This land rise will affect equatorial nations more than any rise due to warmer oceans.
Snowhare
May 18, 2010

Rank: 4 / 5 (12)
@eachus: Congratulations on neither reading or comprehending the article: "In western Greenland, the uplift seems to have started in the late 1990's."
eachus
May 18, 2010

Rank: 1.6 / 5 (13)
You choose how to read that. Either unlike all Europe and North America, Greenland did not start rising until the late 1990s. Not all that unlikely, remember that Greenland could have been higher than its equilibrium position. Again, elementary integration, and Mean Value Theorem. If Greenland was driven down by the accumulated weight of ice from the Little Ice Age and is now rising, there would have been a point in between where it was neither rising or falling.

The other alternative is that no one happened to notice or measure net changes with respect to mean sea level until someone took a GPS and mounted it near the coast. Possible? Sure. At a rate of about a centimeter a year, there could have been no observed change, even if the average mean sea level changed by several feet. Between tides and ice, it would have taken heroic measures to keep a consistent set of sea level over a period of decades prior to GPS.
Caliban
May 18, 2010

Rank: 3.5 / 5 (11)
@eachus,

Enough smoke! If the landmass is rising, then measurements of sealevel taken over the past several years would have been indicating a DECREASE in sea level. Don't be a dolt. Of course it's understood that there are more than one mechanism for uplift/subsidence.

One more thing- if the landmass is, in fact, being uplifted, then that will certainly tend to INCREASE sea level for at least two reasons: icesheet melt adding water to oceans, and the addition of contiguous continental shelf/shallows to upper layer of ocean, and concurrent displacement of equivalent volume of water into surrounding ocean.
PinkElephant
May 18, 2010

Rank: 4.1 / 5 (13)
@eachus,

Anyone who passed calculus would understand that the reported recent *acceleration* in rebound, which occurred on the scale of less than 1 decade, cannot be possibly due to integrated ice loss over preceding several centuries. The time scale of the derivative doesn't match the time scale of the integral. Try again.

And as for this:
Oh, and notice the main effect of raising land levels in areas covered by ice during recent ice ages. This land rise will affect equatorial nations more than any rise due to warmer oceans.
I'll quote the Wikipedia article you linked back at you:
Results of GPS data shows that a peak rate of about 11 mm/year exist in the north part of the Gulf of Bothnia, but this uplift rate decreases away and become negative outside the former ice margin.

In the near field outside the former ice margin, the land sinks relative to the sea. ... GPS data in North America also confirms that land uplift becomes subsidence outside the former ice margin.
TegiriNenashi
May 18, 2010

Rank: 1.6 / 5 (13)
The premise of their article is flawed. There is no recorded temperature increase in the Arctic in the last three decades to cause the alleged melt. How can the ice pack cover remain the same while Greenland ice sheet mysteriously melting away?

BTW, Wikipedia is notoriously biased with warming zealots. It is truly sad that the majority of otherwise quite intelligent people severely lack critical thinking.
PinkElephant
May 19, 2010

Rank: 4.3 / 5 (12)
@TegiriNenashi,
There is no recorded temperature increase in the Arctic in the last three decades to cause the alleged melt.
What's this, then:

http://www.arctic...ps.shtml

How can the ice pack cover remain the same while Greenland ice sheet mysteriously melting away?
Ice cover measures area. Melting impacts *volume*. IOW, thickness can degrade, while area is preserved.
Wikipedia is notoriously biased with warming zealots
Reality tends to be notoriously biased against warming skeptics.
It is truly sad that the majority of otherwise quite intelligent people severely lack critical thinking.
Look in the mirror, and you'll observe one salient example.
PeterdeBruin
May 19, 2010

Rank: 3 / 5 (3)
If the land mass is rising, does that imply that the sea bottom is sinking in compensation?
That might mitigate the sea level rise.
furlong64
May 19, 2010

Rank: 5 / 5 (5)
The Dunning-Kruger effect is always in full force in the comments section!
GSwift7
May 19, 2010

Rank: 2.3 / 5 (6)
There is obviously a delay between ice melting and land rebounding upwards, otherwise the northern hemisphere wouldn't still be rising from the end of the last ice age. That delay implies a gradual accelleration and decelleration of the rebound, not a direct and immediate response. Therefore accellerating rate of rise on Greenland's shore does not conclusively indicate an accelleration of ice melt. It could simply mean that the land is just getting up to speed. How long do you think it takes a continent to go from zero to sixty?

Also, the comment above about land rising in one place means land falling in another is correct. The shape of the earth is balanced by pressure and it's mostly liquid. If you push down in one place the pressure will push up everywhere else, and the converse is true as well. It's like filling a milk jug up with water and partially denting in the sides before puting the lid back on. When you push on one part it will pop the dents back out on other parts.
JayK
May 19, 2010

Rank: 2.6 / 5 (5)
Ah, the TegiriTroll has found its way to another thread and spewed ignorance all over.

As Pink Elephant said, it is about volume, not area. You've been told that repeatedly. Why do you continue to spout the same nonsense in every thread?
GSwift7
May 19, 2010

Rank: 2.3 / 5 (7)
Northern polar ice melt doesn't cause any change in sea level anyway. It's FLOATING, so volume and area are both irrelevant. Floating ice doesn't change the level of water in a container when it melts. It's simple bouyancy. For the causes of sea level rise you need to look elsewhere; such as the parts of the south pole ice that aren't floating, glacier melt, and pumping of underground water reserviors to the surface which eventually gets to the ocean. I suppose you could also include the miniscule shrinkage of the earth due to internal cooling, but I think that's splitting hairs.

I'm not arguing against the data, I'm just suspicious of the conclusion about the rate of rise being directly and linearly related to the rate of melt. It doesn't look like it works that way based on observation of the northern hemisphere.
TegiriNenashi
May 19, 2010

Rank: 1.5 / 5 (8)
My argument is simple, let me spell it out for you one more time. There is a serious doubt about GISS temperature records because they are:
1. Obtained from many often unreliable sources
2. adjusted
3. interpolated onto vast areas such as Arctic
Ice pack cover is much simpler value, this is why I trust it more. For example, I don't challenge the 2007 event.

Now what is this volume argument? We are not talking about mile thick ice sheets, we are discussing floating ice (as temperature proxy). First, there currently is no reliable way to measure thickness (with precision comparable to that of the area). Second, I don't see why it would be important. For ice thickness argument to work one have to imagine the two scenarios under two different temperature conditions the ice area stays the same, but it thickness differ. I find hard to believe it.
JayK
May 19, 2010

Rank: 3.5 / 5 (8)
@TegiriTroll: The word that you might be looking for is "perenial". Larger volumes of ice stay around a lot longer, increasing albedo. It is a major part of a feedback loop. There is no arctic ice recovery because the volume, per year, continues to decrease.

You find it hard to "believe it" because you are nothing more than a global warming thread troll with nothing to add except your own ignorant incredulity.
TegiriNenashi
May 19, 2010

Rank: 1.4 / 5 (10)
Let me spell out the problem with junk studies like this. They take complex phenomenon (e.g. glassier dynamics), often a very complex one (e.g. butterfly migration pattern, lizard extinction event) and suggest that its correlation with much more simple and profound effect contributes to the proof. That is ridiculous, for simple phenomena (average temperature change) you look for simple and reliable measurements.
TegiriNenashi
May 19, 2010

Rank: 1.6 / 5 (10)
The word that you might be looking for is "perenial". Larger volumes of ice stay around a lot longer, increasing albedo.


How do you think satellite measures ice pack cover? It has a photo sensor, and based upon the imagery (if the area is mostly blue or white) decides if it is ice covered or not. In a way, it records albedo directly!
JayK
May 19, 2010

Rank: 3.5 / 5 (8)
It has a photo sensor

You got something right! Good job, get yourself a cookie before nap time.
based upon the imagery (if the area is mostly blue or white) decides if it is ice covered or not.

Wrong! No cookie for you!

Scanning Multichannel Microwave Radiometer (SMMR) and Special Sensor Microwave/Imager (SSM/I) is used to determine ice extent and from those readings the volume is estimated. While there are photo sensors, they aren't used for more refined calculations. If you were even remotely serious, you'd have known that, or at least suspected it.
TegiriNenashi
May 19, 2010

Rank: 1.4 / 5 (9)
CryoSat-2 will test the validity of the thickness argument with cm precision. Until that time it is just speculation.
JayK
May 19, 2010

Rank: 4 / 5 (12)
Until that time it is just speculation.

No it isn't. Where the hell did you come up with that? They've also been using EM based thickness measurements from ships and expeditions, on top of ice cores. The precision will be nice, but it isn't necessary to just wait for the results. Do you even know what the word "speculation" means? Do you have a scientific basis for any of your thoughts on AGW or are you just bored and trolling when you're supposed to be in gym class?
GSwift7
May 19, 2010

Rank: 3 / 5 (4)
@Tequiri: I think speculation is too strong of a word. The difference between current estimates of ice thickness and readings from Cryosat 2 isn't expected to be very big. Although very expensive and time-consuming to collect, there is extensive data on ice thickness from aircraft, submarine, and ground observations. The Cryosat 2 data is predicted to hold few surprises, but you never know till you look. Sure it's possible that we'll discover something unexpected but not likely. A cynical person might even say that the people callibrating the instruments on Cryosat 2 are the same people claiming that the ice is melting, and that they would in effect be calling themselves stupid if they suddenly say that they were wrong about that. Not that NASA, NOAA or NCDC would ever do something like that though (google climategate). Under those circumstances, the data wouldn't be speculation, it would be opinion. But that would be a very cynical way of looking at things, so I won't.
Skeptic_Heretic
May 19, 2010

Rank: 4.3 / 5 (10)
If anyone is doubting multiyear ice volumes falling, there's a great progression simulation based off of the satellite measurements on NASA's site. The volume of yearly ice may be increasing or decreasing, but that doesn't speak to the amount of multi-year ice. It's rather telling, and has changed my opinion on the matter.

A lot of skeptics are changing their tune now that we're seeing good datasets over statistically significant timescales. Warming is most certainly occuring. The cause isn't nailed down, but CO2 is the leading hypothesis and as so far it sits unrefuted.
Caliban
May 19, 2010

Rank: 3.7 / 5 (9)
Northern polar ice melt doesn't cause any change in sea level anyway. It's FLOATING, so volume and area are both irrelevant. Floating ice doesn't change the level of water in a container when it melts.


@GSwift7,
A couple of fallacies in your thinking:
1. the Greenland icesheet is primarily resting ON LAND, not water, and therefore, as it melts, it is sea level ADDITIVE, in no way different than pouring water into a glass.
2. There is a net positive addition to sealevel when "sea ice" melts too: namely, the difference between the volume of solute in the salt water vs the freshwater ice, plus the "Bridged, or Suspended" ice that forms inshore, that is partially or fully supported by the shore itself, rather than bouyed. Smallish additive amounts, but not negligible.
eachus
May 19, 2010

Rank: 1.4 / 5 (10)
Warming is most certainly occurring.

Correct.

The cause isn't nailed down, but CO2 is the leading hypothesis and as so far it sits unrefuted.

Wrong. Every statistically valid test of the relation between CO2 and global warming, has shown that higher temperatures cause higher CO2 levels, not the other way around. The AGW people claim that human contributions to CO2 levels are unprecedented, and as such are not refuted by the relation between temperature and CO2 levels over the last few million years. (CO2 levels lag temperature by about 800 years.)

For anyone who wants to debate AGW though, those two facts should be the starting point, instead of sweeping the second under the table.

In recent years whenever a public prediction has been made that due to CO2 forcing thus and such will happen, just the opposite occurred. You might want to contend that God has a seriously warped sense of humor, but that is the status quo.
PinkElephant
May 19, 2010

Rank: 4 / 5 (8)
@eachus,
CO2 levels lag temperature by about 800 years.
The historical relationship b/w temperature and CO2 is that of feedback. Increased temperatures cause more CO2 outgassing from oceans, which leads to a knock-on increase in temperatures, which leads to a knock-on CO2 outgassing, which leads to... and so on and so forth. At each iteration of the feedback cycle, the increments diminish (logarithmically) until the system asymptotically stabilizes.

Massive anthropogenic CO2 emissions are a historically new phenomenon, artificially pumping additional greenhouse gas into atmosphere, at annual rates well exceeding 100x total natural volcanic emissions across the globe.

This will cause warming, which will cause more CO2 outgassing from oceans, which will cause more warming, etc. Except this time, there's an added artificial driver in the system, and so this time, CO2 is leading temperature.
TegiriNenashi
May 19, 2010

Rank: 1.5 / 5 (8)
Again, why multiyear ice is relevant? A cynical way to view it is noticing how believers changed the tune since the great 2007 melt turned out to be a fluke. So when Cryosat 2 would demonstrate no change in thickness what else would they blame? "rotten ice"?

All this talk about the Arctic allegedly melting is avoiding inconvenient fact that Antarctic still fairs pretty well. This is confirmed both by ice pack extent measurements and temperature stations. Why asymmetry? Don't be quick to jump in with ridiculous "polar vertex" and "ozone hole": you are explaining something *after the fact*. It is your ability of making reliable predictions that is challenged.
PinkElephant
May 19, 2010

Rank: 4 / 5 (8)
@TegiriNenashi,

I don't know if you noticed, and it's already been pointed out above, but the ice in question here is the 2 km thick glacier covering GREENLAND. We aren't, in this instance, talking about polar ice sheets that float on the arctic ocean. While the distinction between old and young sea ice is indeed important, as are the times of melting/icing seasonal onsets, these are completely irrelevant when discussing what's going on with GREENLAND. Greenland is rebounding at an accelerating pace, meaning that its glacier is losing mass at an accelerating pace.
TegiriNenashi
May 19, 2010

Rank: 1.8 / 5 (5)
They installed GPS receivers in the late 90s so, how do they know that the "accelerated" uplift started in the late 90s? And WhereTF is the graph that readers can witness the "accelerated" shape? (The reason for being not polite with 3 letter abbreviation is that the term "accelerated" together with "worse than we thought" is abused and not very original)
PinkElephant
May 19, 2010

Rank: 3.9 / 5 (7)
how do they know that the "accelerated" uplift started in the late 90s?
Since their data goes back to 1995, one would surmise that by "late 90s" they're talking about somewhat later than 1995 (which would have been more properly described as "mid 90s".) Moreover, it's not important whether the acceleration 'started' in late 90s. What's important is that it's been accelerating since then, to a point that right now it's clocked at 25 mm per year, and is expected to double, reaching 50 mm per year, 15 years from now. Now, before you fly off yet another handle, this uplift affects only coastal areas, so far: the inland glacier seems to be holding up, for now, as again mentioned in the above article.
And WhereTF is the graph that readers can witness the "accelerated" shape?
Again as mentioned in the article, the graph is in the latest edition of Nature Geoscience. If your local library subscribes, maybe you could take a look for free...
Shootist
May 22, 2010

Rank: 1.6 / 5 (7)
@TegiriNenashi,

I don't know if you noticed, and it's already been pointed out above, but the ice in question here is the 2 km thick glacier covering GREENLAND. We aren't, in this instance, talking about polar ice sheets that float on the arctic ocean. While the distinction between old and young sea ice is indeed important, as are the times of melting/icing seasonal onsets, these are completely irrelevant when discussing what's going on with GREENLAND. Greenland is rebounding at an accelerating pace, meaning that its glacier is losing mass at an accelerating pace.


No. You misinterpret the data. Greenland has been rebounding for the last 10 thousand years.

The big question is; where are the dairy farms? Greenland had a thriving dairy industry from AD 800 until AD 1400. If it is so warm, where are the dairy farms. Oh, it is still too cold, eh?
PinkElephant
May 22, 2010

Rank: 4.3 / 5 (6)
@Shootist,

Maybe you should stop swilling right-wing mental poison. It's not good for you...

http://www.spiege...,00.html

http://www.enviro...gain/392

Lookie what a simple 2-minute Google search can do...
Caliban
May 22, 2010

Rank: 3.5 / 5 (8)
The big question is; where are the dairy farms? Greenland had a thriving dairy industry from AD 800 until AD 1400. If it is so warm, where are the dairy farms. Oh, it is still too cold, eh?


Of Course it's TOO COLD, you bonehead! The whole land mass, with only a small fraction exception, IS COVERED IN ICE! Stop with this whole idiotic "Greenland Farms Dairy" meme you seem to have stuck in your talk-box.

In case you weren't aware, there are circulating coldwater currents around Greenland, which keep the average temperature low enough to sustain the icesheet year over year. The fact that there is SUBSTANTIAL REDUCTION of this ice mass clearly points to average temperature increase sufficient to cause a net loss of ice mass- and quite a large one.

Perhaps in twenty years-maybe less- your cherished dream of Greenlandic dairies will once again be a reality. Until then, quit invoking it as some sort of magic-bullet AGW debunker. It simply isn't sufficient argument.
Skeptic_Heretic
May 23, 2010

Rank: 4 / 5 (4)
The big question is; where are the dairy farms? Greenland had a thriving dairy industry from AD 800 until AD 1400. If it is so warm, where are the dairy farms. Oh, it is still too cold, eh?

If you've noticed, wind currents appear to drive the warmth and cold spells in Europe far more readily than any global average, as can be evidenced by the anomalous 2003 heat wave and the anomalous 2009 cold spell and storm intensities.

As Caliban said, this argument loses relevance when you look at a large framework of the climate system.
Shootist
May 23, 2010

Rank: 1.6 / 5 (7)
If you've noticed, wind currents appear to drive the warmth and cold spells in Europe far more readily than any global average, as can be evidenced by the anomalous 2003 heat wave and the anomalous 2009 cold spell and storm intensities.

As Caliban said, this argument loses relevance when you look at a large framework of the climate system.


Those dairy farms existed for >500 years and were not negatively impacted by normal variations in weather. Your 'hot' and 'cold' spells are normal variations in weather.

Your suggestion is that the MWP (medieval warm period) didn't exist. It did. Why do you deny it? Vineyards in Scotland. Dairy Farms in Greenland. TOO COLD NOW for either. And the Roman warm period was warmer and lasted longer than, the MWP. And with temps higher than ANYTHING seen today. And all that with little anthropomorphic CO2.

AGW is bunk and will be used by nefarious men to take your wealth and give it to someone else, while dipping their beak as well.
Skeptic_Heretic
May 23, 2010

Rank: 3.7 / 5 (6)
Those dairy farms existed for >500 years and were not negatively impacted by normal variations in weather. Your 'hot' and 'cold' spells are normal variations in weather.
And normal variations in climate are normal variations of weather over long timescales.

I do not deny the Medieval Warm Period, nor do I state that it was a localized event.

Those two stances are not mutually exclusive. You're engaging in a straw man and you don't even know it.
PinkElephant
May 23, 2010

Rank: 4.4 / 5 (7)
@Shootist,
Vineyards in Scotland. Dairy Farms in Greenland. TOO COLD NOW for either.
I've already linked you some info about dairy farms in Greenland. And here are some vineyards in Scotland:

http://www.totalt...reweries
AGW is bunk and will be used by nefarious men to take your wealth and give it to someone else, while dipping their beak as well.
Let me rewrite this for you:

AGW *denial* is bunk and will be used by nefarious men to take your wealth and give it to someone else, while dipping their beak as well.

What a difference 1 extra word can make...
Skepticus_Rex
May 24, 2010

Rank: 1 / 5 (5)
PE,

The link you gave points to whiskey distillers in Scotland while falsely placing them on pages for wineries and vineyards and farms.

So far as I am aware, they do not distill whiskey in vineyards. The website you are using is providing not-so-correct listings. Want to see a real list of Scotland Vineyards? Go here:

https://www.local...cotland/

Choose any of the cities from the dropdown box and notice that as of this post there is nothing listed.

For every city listed I get:

"Sorry, we don't have any Wineries and Vineyards listed yet.

Help us out by spreading the word about our site to all your Winery friends. If you would like to submit your information, click the "Submit" button directly above this."

If you know of some actual vineyards in Scotland, however, please do add them to the list and give verification so that they can be added to the listings permanently. :)
Skepticus_Rex
May 25, 2010

Rank: 1 / 5 (3)
Just wanted, for good measure, to add the following comment from a newspaper site in the Isles.

"Julie Trustram Eve, from English Wine Producers, said: "There are as far as we know no vines yet in Scotland, although there have been rumours. It's gradually creeping up. It depends how accurate the predictions are for the long term, but some say by 2080 it will be too hot to grow grapes in southern England."


Above quote taken from:
http://www.telegr...say.html
Skepticus_Rex
May 25, 2010

Rank: 1 / 5 (6)
One question that might be asked might be: Is land really rising due to mass loss or are sea levels falling? Geological change? There are other areas in the world where sea levels have either stayed or have fallen. A number of these areas cannot be explained in terms of mass loss from melting ice.

That there is ice melting in Greenland is true. However, it did it 50% faster from 1920-1930 than it did in the years 1995-2005. CO2 could not have been responsible for the faster melting and faster rising temperatures of the warmest decade in Greenland in recorded monitoring of temperatures.

Are we so sure it is responsible now? I still remain unconvinced for the time being. I, however, could change my mind if I see some better evidence than I have been seeing of late.

After all, even the above study states: "The measurements are restricted to places where rock is exposed, limiting the study to coastal areas."

To know for a certainty more data must be taken from further inland.
Skepticus_Rex_
May 25, 2010

Rank: 1 / 5 (3)
Of course I know that 57,000 people live on Greenland now, more than during that regional MWP.
They don't grow mangoes or pineapples in Scotland yet the vikings used to in Greenland. I had the links to proive this but my Banjo has just got stuck up my nose whilst I was picking it...the Banjo not the nose :)
Skepticus_Rex
May 25, 2010

Rank: 1 / 5 (4)
Hey, JayK's/MikeyK's rear-underscore sockpuppet copy of me still lives. Wonderful! :)

By the way, I do not play Banjo. Sounds like fun, though.

Does not change the facts, however, as well as it does not answer the questions about the range of uncertainties with studies such as the above.

Here is the thing. They may not have GIS measurements taken from anywhere there but the coasts alone but there is a way to do better. It is rather simple.

Just plant very long towers onto the bedrock and fasten them. This can be done where ice cores have already been taken. Yes, the infrastructure will not be cheap but I think it is a worthwhile investment into both Climate and Geological Sciences.

Is Greenland really rising due to mass loss? That is a question that cannot be answered with certainty under present conditions. Until such infrastructure is set up, the answer to the question will remain uncertain for the foreseeable future.
Skeptic_Heretic
May 25, 2010

Rank: 3.4 / 5 (5)
One question that might be asked might be: Is land really rising due to mass loss or are sea levels falling?
Satellite measurements answer these questions. The land masses are rising, that is certain.

Skepticus_Rex
May 25, 2010

Rank: 1 / 5 (4)
Could you please point me to the Satellite measurements of which you speak? The only ones of which I am aware at the moment are those only taken on the coastlines where there is exposed rock.

This is insufficient to answer the question concerning the remainder of the Greenland landmass. For instance, if only portions of the coasts are rising whereas the rest of Greenland may not be rising, can we really attribute the coastal rise to melting ice mass loss?

Satellites cannot pick up rising landmass with ice on top as the tops of the ice itself will build up and rise with added precipitation and fall with melt.

This is why I advocated placing towers onto the bedrock directly so as to prevent erroneous readings taken from GIS positioning and tracking from further inland.
thermodynamics
May 25, 2010

Rank: 1.8 / 5 (5)
Skepticus_Rex: Try this data set that is a combined effort of satellites and shoe-leather. You have to do a little of your own work to get what you are looking for but it is there.

http://nsidc.org/...092.html

Your idea of placing towers in the bedrock has been tried before. Unfortunately the glaciers tend to shove them along or snap them off like twigs.

And the satellites can discern the changes in thickness of ice from the rising land in conjunction with land explorations to verify and supplement the satellite measurements. There are a number of experiments going on now looking at exactly what you are talking about to determine what the change in glacier thickness and change in land surface is. We will probably see the results here in a while. Stay tuned.
Skepticus_Rex
May 25, 2010

Rank: 1 / 5 (2)
I actually am looking forward to the new data. I just want to make sure that we can say things like this with more certainty.

We all know what happened with the IPCC and all the errors that are being found, and counting, in their reports. We also now know how foolish it is to use terms like 'unprecedented' when such often turns out not to be the case when we compare data and historical records from the past. :)
Skepticus_Rex
May 25, 2010

Rank: 1 / 5 (2)
Oh, crap, thermodynamics! I actually got my hopes up for nothing. The information at the site to which you referred me is NOT current. Bummer.

The metadata gives me:
Temporal Coverage
Start Date: 1970-01-01
Stop Date: 1970-12-01

Start Date: 1993-01-01
Stop Date: 1999-12-31


I need something more current, please. :)
Skepticus_Rex
May 26, 2010

Rank: 1 / 5 (2)
Unfortunately the glaciers tend to shove them along or snap them off like twigs.


Ummm, I never said anything about placing them in active glaciers... Foot-in-mouth syndrome or just dyslexia?
thermodynamics
May 26, 2010

Rank: 1 / 5 (2)
Skepticus: Sorry that was old data. There is a lot more where that came from. You can add this to the older data and get a comparison. Actually this is just showing the way they minimize uncertainty in the measurements.

http://icesat.gsf...adar.pdf

This one is brief but has some interesting references to find and shows measurements being taken up through 2008. The new Cryosat 2 satellite has just been launched into a near polar orbit and should give us a good view of the ice on both poles.

http://www.pages-.../Special section/science highlights/Bamber_2009-2(52-54).pdf

Again, sorry for the older data the first time. I didn't look long this time either.
thermodynamics
May 26, 2010

Rank: 1 / 5 (1)
Sorry about the last post. The second reference did not come through well. You will have to click on the first part and then cut and paste the second part on when it tells you it is a bad address. I'll try again but I'm not holding out hope so the cut and paste is probably still the better way to go.

http://www.pages-.../Special section/science highlights/Bamber_2009-2(52-54).pdf
Skeptic_Heretic
May 26, 2010

Rank: 4 / 5 (4)
Ok Skepticus,

I'm going to go the science route here and ask you what evidence or observation you have to show that the continental plates are sinking rather than the sea level rising. We can engage in blind supposition all day long, but rather than saying "nuh uh!" let's be reasonable and logically talk it out.

What've you got? I'm completely unbiased and reading everything I can on the issue. Enlighten me.
Skepticus_Rex
May 26, 2010

Rank: not rated yet
Skeptic_Heretic,

So far as I am aware, I never said that the continental plates are sinking, per se, so I do not know what it is that I can show you. I also am not a Geologist.

However, it is a fact that there are areas where apparent sea level is falling rather than rising, and some of these do not have readily apparent geological causes. There are various websites that actually show the changes in sea level amongst the various cities and other locations of the world.

On the matter of sea level rising, even the TOPEX satellite-based observation data showed that there were places where sea level either stayed the same or had a negative or falling sea level, whereas other places had a very definite rise in sea level, particularly where the currents push hotter water.

I, too, am completely unbiased, which is why I ask questions in the manner that I do. I want to make sure that I see the best data possible so as to remove as much wiggle-room as possibly can be removed.
thermodynamics
May 26, 2010

Rank: 2.3 / 5 (3)
Skepticus_Rex: OK, I am going to take you at your word that you are unbiased and want to understand what is happening. I am going to point you at two sites. The first site is a simplistic view of "sea level." Note that I put the term in quotes. The reason is that the level of the sea is not a simple thing and people treat it like it is. I deal with combustion and people ask me what the temperature of my flames are. I have to respond that there is no such thing as a flame temperature because flames are heterogeneous structures. Sea level is just a complicated. The first site is:

http://sos.noaa.g...sha.html

Geodesy is the way that gravity interacts at a surface. Carried to the next post->
thermodynamics
May 26, 2010

Rank: 2.3 / 5 (3)
A good reference to geodesy can be found at:

http://en.wikiped.../Geodesy

The interplay between the simple view of mass change (melting or freezing water) and temperature (expansion and contraction of water) is complicated by the fact that the gravitational field is also heterogeneous and changes - just as the other variables do. As an example the tides are caused by the moon influencing the gravitational equipotential surface of the earth. The key is that we need to tease the mass portion of the signal out of the thermal heating and geodesy of the earth. Over a span of time the gravitational influences average out (except for changes like the large earthquakes which change the orbital precession of the earth and modify the geodesy). That leaves us with teasing the mass signal out of the total signal. That is the reason that looking at sea level is not as good an indicator as we would like. So, the task is to make an accurate mass balance given all of the unknowns.->
thermodynamics
May 26, 2010

Rank: 2.3 / 5 (3)
I hate the 1000 character limit. What is going on now is that we have modestly accurate measurements going back about 100 years. We have good accuracy for the past 15 years and we are starting to have excellent accuracy now. Start looking at mass balances. The idea of sea level is one that can be played with since it does vary considerably and it can be used as an argument for almost any side of the table. Keep an eye on those who talk about sea level in terms of mass increase or decrease. Also look at sources of mass. Watch how those trend. Sorry to be long winded, but this is one of the things that people go off on tangents about and can lead to circular arguments. If the sea levels are a proxy for mass gain (which AGW supporters claim) or if it is not a good proxy (as AGW-deniers claim) then it can be used for both sides of the argument. It can be claimed it is local heating or the contribution from Greenland. You have to look at the papers that cover the source.
Skeptic_Heretic
May 27, 2010

Rank: 3.7 / 5 (3)
I, too, am completely unbiased, which is why I ask questions in the manner that I do. I want to make sure that I see the best data possible so as to remove as much wiggle-room as possibly can be removed.
You can't be completely unbiased as you have a presupposition that AGW is incorrect. The problem here is there is no mechanism that we know of that can account for the thermal forcings we're seeing, the temperature has gone up. And yes we can play games with what time we start with and when we end and mess around with mean lines and trend lines, but the raw data, when passed through reasonable statistical mechanisms does show a strong upward trend that is incongruent with known climatological forcings. This is leading directly to increased melt of most glaciers in most, but not all, cases. Aside from that, we know the primary cause of ice loss is ablation, primarily wind ablation, and through our land use changes and potential impact on temperature we're increasing wind speeds.
Skepticus_Rex
May 27, 2010

Rank: 1.5 / 5 (4)
...You can't be completely unbiased as you have a presupposition that AGW is incorrect....


I think you need to go back and read my actual posts rather than those of JayK's rear-underscore sockpuppets. You have got to watch for the extra underscores in the name. I have stated several times my actual stance on the matter in several places.

On the matter of climate forcings, even Dr. Phil Jones and others have admitted for the public record that neither warming nor cooling have been statistically significant from 1995 to the present. Has there been warming? It is a rather steep curve since the LIA.

But, take the stats back to before the MWP and we have not gotten back to where it was during the MWP.

Furthermore, go back and read Chylek et al., 2006, and you will see that it warmed 50% faster in 1920-1930 in Greenland than from 1995-2005. The CO2 just wasn't there.

On land use changes, I agree completely. I firmly believe land use changes significantly impact climate.
Skeptic_Heretic
May 27, 2010

Rank: 3.7 / 5 (3)
On the matter of climate forcings, even Dr. Phil Jones and others have admitted for the public record that neither warming nor cooling have been statistically significant from 1995 to the present. Has there been warming? It is a rather steep curve since the LIA.
So if you've run the stats and done your homework, you know that the question asked of Phil Jones was misleading. That question was formulated very particularly to force Jones to say something uncomfortable. If you start at 95 you get no significant warming. If you step back one year you enter the realm of significance as the longer the timeframe the easier it is to determine statistical significance. If Jones was asked that same question today, his answer would be "yes, it has been significant" as we've added 1 more year to the record. You should have known better than that.

Post limit sucks but I think that is significant enough a rebuttal to your opening statement.
Rank 4.1 /5 (25 votes)
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