Greenland Ice Sheet is Melting Faster, Study Says

National Geographic ^ | 08/10/2006 | John Roach

[pfony1]

Thanks for the ping.

I think it's interesting that the scientific measuring device referenced in post #96 which, according to its promotional website,

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http://sealevel.jpl.nasa.gov/mission/topex.html

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"MISSIONS - TOPEX/Poseidon
Launched in 1992, TOPEX/Poseidon is a joint venture between CNES and NASA to map ocean surface topography. While a 3-year prime mission was planned, with a 5-year store of expendables, TOPEX/Poseidon has delivered an astonishing 10+ years of data from orbit. In these 10+ years, it has:

Measured sea levels with unprecedented accuracy to better than 5 cm...."

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has "...accuracy...better than 5 (FIVE!!) centimeters..."

NEVERTHELESS has been used to "calculate" a change in the average height of the world's oceans of 0.5 mm per year.

Please color me sceptical...

It's like these "scientists" have learned nothing from "How They Weigh Pigs at UC-Berkeley".

Sheeesh....

[YOUGOTIT]

"Greenland was a ruse created by Eric the Red"

Sorry not true. the archaeological digs have proven that Greenland was much warmer around 900 to 1400 AD than it is now. They were able to grow corps etc. But after it started to get cold when the mini Ice age came they were no longer able to live there. But they did live there for a few hundred years.

[cogitator]

How much is melting ice, and how much ocean expansion?

I'm not sure; I think ocean expansion is the dominant term.

[Omedalus]

I was just noticing the same thing; that the data is actually VERY linear for the last ten years.

This data does answer some of my earlier questions. However, in the last 10 years, China's manufacturing base has grown immensely and India has grown a middle class. You'd think that the corresponding increase in fossil fuel consumption would cause the rate of sea level rise to increase. However, it has stayed very linear for all ten years. (Yes, I know how to read a graph, and I understand that the trendline is linear by design. I'm not talking about the trendline, I'm talking about the data that feeds into the trendline, which does not seem to visually depict an increasing rate of sea level rise.)

It couldn't be the the satellite that's de-orbiting at a rate of 3mm per year, could it? :)

Either way, this data purports to prove that sea levels are rising by about an inch a year. That's nice. My continental plate is shifting at about two inches per year or more. Why exactly should I go all hysterical over changing sea levels when I'm already totally complacent about tectonic shift?

I'm not just trolling here. I'm dead serious. Plate tectonics simply does not affect my day-to-day existence. I don't get freaked out at the prospect that my coastline might be two inches further to the west this year than it was last year - and my office building is fifty feet away from the waterline of Puget Sound. If the magnitude of the change to my environment that I might expect as a result of global sea level rise is one-twentieth that of the year-to-year change I experience anyway, then why exactly should I care? Why should anyone?

[cogitator]

By averaging numerous multiple measurements (rather than a single measurement good to +/- 5 cm) the long-term sea level rise can be extracted from the data. The satellites are on an exact repeat orbital cycle, meaning that they pass over the exact same places every 10 days (I think it's a 10-day cycle, that could be incorrect). So by measuring repeatedly, the other variable factors average out, leaving the long-term trend.

[Omedalus]

"How they weigh pigs at UC-Berkeley"? Hmm. This sounds juicy. What's that?

[RainMan]

Whether you choose to believe it or not, the "ruse" was that "Iceland" was actually a relatively nice place to be, with geothermal vents for natural heating, good access to abundant fishing grounds, and enough arable soil to sustain crops. Greenland however, had none of these.

Fearing word would get back to Europe about a new land that held promise, he chose to name the icy-hell "Greenland" and the promising territory "Iceland" - exact opposites of what they were - hoping that prospective raiders would first chose to go to "Greenland", and seeing how unwelcoming it was, would shun exploring "Iceland" all together.

Basically, he wanted them to think that if Vikings considered Greenland to be Green, then you could imagine how bad a place Vikings called Iceland would be.

[palmer]

The quantification of attribution between human (anthropogenic) causation and natural variability factors is still uncertain, though it is becoming progressively less so.

I don't think there's much consensus when you break down the elements. The CO2 is only agreed to add about a degree C but there are other AGW advocates who talk about more without being very quantitative. The water vapor feedback doesn't bring much consensus since the models break down into parameters like albedo that aren't going to be generally agreed on. Each time you peel back another layer from other GH gasses to various other feedbacks, there's plenty of disagreement about physical processes involved.

The problem with reading certain sites like RC is they don't want to admit that the underlying uncertainties can invalidate their preconceived conclusions.

[YOUGOTIT]

"Greenland however, had none of these."

That is what used to be taught in school but has been proven to be untrue. Greenland according to archaeological evidence was green and could grow crops and animals until the temperature changed around 1400 plus or minus.

[pfony1]

It works like this:

FIRST, find a FULCRUM and a long, strong LEVER.

SECOND, move the LEVER on the FULCRUM until the two sides are in EXACT balance.

THIRD, place the pig in the middle of one side of the LEVER.
(Note: this process works best if the pig is "docile". Since you will probably find it necessary to "relax" the pig with a gallon of two-buck-chuck, remember that a gallon is 128 ounces).

FOURTH, place a stone on the OTHER side of the LEVER.

FIFTH, move the stone towards the FULCRUM or away from the FULCRUM until the pig-side and the stone-side are in EXACT balance.

SIXTH, measure the distance of the pig (= Dp) from the FULCRUM EXACTLY and measure the distance of the stone (= Ds) from the FULCRUM EXACTLY. (Note: Measuring to the nearest millimeter will enhance accuracy.)

SEVENTH, guess the weight of the stone (= Ws)

EIGHT, the weight of the pig (Wp) may be calculated with FOUR-DIGIT-PRECISION using the following equation:

Wp = [(Ws x Ds)/Dp] - 128 ounces

This method has never failed to produce an answer at UC-B.

[pfony1]

You said,

"By averaging numerous multiple measurements (rather than a single measurement good to +/- 5 cm) the long-term sea level rise can be extracted from the data."

I think that is the "conventional wisdom" -- but it defies logic.

An "average" of CRUDE numbers is not by the process of "averaging" made into a PRECISE number.

I understand that "professional" statisticians have a different opinion based on what they ASSUME are standard data populations, standard deviations etc.

But, IMHO, that self-promoting opinion is wrong...

[palmer]

So by measuring repeatedly, the other variable factors average out, leaving the long-term trend.

My impression is that sea level is all about wind. There are seasonal and cyclical changes as the prevailing winds change. Finally the weather pattern changes as a result of global warming will change the winds and sea level measurements. The average sea level can't be based on equally spaced measurements. There may not be such a thing as average sea level, just various biased local measurements where it is necessary to understand the biases.

[HIDEK6]

The Greenland ice sheet is melting three times faster today than it was five years ago, according to a new study.

I think this is good news for all the Greenlandians.

[HIDEK6]

If the Antarctic sheet were to completely melt ocean levels would rise about 500 feet.

I sure hope this doesn't mean I have to move back to Ohio.

[I'm ALL Right!]

You Win!

[CWOJackson]

Looks good for my ocean front property in south central Indiana. I should get busy building the dock now.

[carumba]

Okay, class, did you see how fast he figured that out? Bueler? Baahuuuulerrrrr?

[Einigkeit_Recht_Freiheit]

I do. Just razzing you.

[Einigkeit_Recht_Freiheit]

When I say it is the speed of the melting I meant he acceleration. Indeed 60 u miles is irrelevant. But if the melting continues to increase exponentially then we quickly achieve as signficant amount.

[Einigkeit_Recht_Freiheit]

I totally ignored it because it is a scare tactic and ludicrous. If we get to the point where the rise in the ocean levels will dramatically affect our civilization we are going to be pretty far gone anyway.

The biggest issue with the Greenland ice sheet is its capacity to dramatically alter the Gulf Stream. The measurements of the melting ice are far more accurate and can be visibly observed via satellite photos.