[Note: this post (and a few others) was lost in WordPress, and I had no notification of its existence. While a bit dated, it is still valid – note to guest authors with WUWT WordPress privileges – when you submit something, be sure to notify me via email too – Anthony]
Guest post by David Middleton
From Live Science…
Records Melt Away on Greenland Ice Sheet
By Brett Israel, OurAmazingPlanet Staff Writer posted: 21 January 2011
The disappearing Greenland Ice Sheet set several records during an unusually long melt last year, according to a new study.
Running from April to mid-September, the melt season of 2010 was about a month longer than usual, said study team member Jason Box, a geographer and climatologist at Ohio State University.
[…]
“The disappearing Greenland Ice Sheet”… Where in the heck did the author get the idea that the Greenland Ice Sheet was disappearing?
A recent publication by a team from TU Delft & JPL found that the Greenland ice sheet was melting at half the rate previously thought. They estimate that the Greenland ice sheet is losing ~230 gigatonnes (Gt) of ice per year. One Gt of water has a volume of 1 cubic km (km^3). 1 Gt of ice has a larger volume than 1 Gt of water… But, for the purpose of this exercise, we’ll assume 1 Gt of ice has a volume of 1 km^3.
If 1 Gt of ice has a volume of 1 km^3 and the current volume of the Greenland ice sheet is ~5 million km^3 and Greenland continues to melt at a rate of 230 km^3/yr over the next 90 years… The Greenland ice sheet will lose a bit more than 0.4% of its ice volume.~230 gigatonnes (Gt) of ice per year equates to about 0.005% of ice mass loss per year. At the current rate, it would take 1,000 years for the Greenland Ice Sheet to lose 5% of its volume.
The Earth’s climate was at least 2°C warmer during the Holocene Climatic Optimum and the Greenland Ice Sheet did not melt, disappear or destabilize…
The Earth’s climate was at least 2°C warmer and the Arctic was about 5°C warmer than it currently is during the Sangamonian (Eemian) interglacial. and the Greenland Ice Sheet did not melt, disappear or destabilize.
Greenland’s glaciation began during the Miocene, when the Earth’s climate was at least 5°C warmer than it currently is. It advanced rapidly after the Mid-Pliocene Warm Period.
Earth’s climate would have to warm back up to where it was in the mid-Miocene (~15 MYA) in order to destabilize the Greenland ice sheet…
There is no scientific evidence to back up the assertion of a “disappearing Grrenland Ice Sheet. For a detailed explanation as to why the Greenland ice sheet cannot collapse under any AGW scenario, see Ollier & Pain, 2009.
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“There is no scientific evidence to back up the assertion of a “disappearing Grrenland Ice Sheet.”
And the same goes for all the other scare based propaganda that we’re recycling at this blog.
There is no scientific evidence, Period
Please someone help me. Was the snow green during the medieval warming period when the Vikings named it gruenelande? Dumme verschlachtekopffe!
One gigaton of water raises the oceans about 2.78 microns. 230 gigatons of water spilling off of Greenland per year raises the oceans about 0.64 millimeters per year or about 2.5 inches per century. Pretty scary.
See…
http://climatesanity.wordpress.com/conversion-factors-for-ice-and-water-mass-and-volume/
“It is an edged cliché that the world is most pleasant in the years of a Waning Sun. It is true that the weather is not so driven, that everywhere there is a sense of slowing down, and most places experience a few years where the summers do not burn and the winters are not yet overly fierce. It is the classic time of romance. It’s a time that seductively beckons higher creatures to relax, postpone. It’s the last chance to prepare for the end of the world.”
Vernor Vinge, _A Deepness in the Sky_ Ch. 4, 1999
There you go again, promulgating pesky facts as if they were…well, facts.
Yes, yes, but…what about the children?!?
See http://www.nasa.gov/topics/earth/features/earth20110308.html
“…for each year over the 18-year study, the Greenland ice sheet lost mass faster than it did the year before, by an average of 21.9 gigatonnes a year. In Antarctica, the year-over-year speedup in ice mass lost averaged 14.5 gigatonnes.”
230GT from Greenland – and accelerating at about 10%/year? You might want to run your numbers again; that adds up to ~2.1% of Greenland ice melting in the next 90 years, not 0.4%. Also keep in mind that Greenland doesn’t have to completely melt to cause trouble.
Running some more numbers, 1.3mm/year sea level rise from the current 475GT melt (Greenland plus Antarctic ice loss), accelerating at 36.3GT/year:
That adds up to 0.515 meters of sea level rise in the next 90 years, plus thermal expansion. One meter of sea level rise by 2100 is entirely possible…
KR: “Accelerating” at 10% since maybe 1985 at best. Gaining ice before that. Not significant.
IIRC, potholer had graced this issue with a video, saying that it isn’t so much the melt rate, but rather the lubricating effect of melt water underneath, which makes it basically slide a lot faster. I hope I am not mis-quoting him though; maybe someone has heard this before?
KR
Over the past 18 years, the Antarctic ice sheet has increased in volume, not decreased as postulated in this paper. Only the Western pennisula has lost ice during the past two decades. Perhaps their estimates for Greenland are also inaccurate!
Bill
KR: How does that compare to daily high tide/low tide differential? Or to a tsunami?
KR says:
April 5, 2012 at 1:10 pm
Okay, the suspense bothers me. I’ll bite. How much of Greenland (I assume you mean Greenland’s ice sheet) will have to melt before anyone will notice that trouble is being caused, how will anyone notice, and for how many million years will we have to wait before someone will notice?
David Larsen says:
April 5, 2012 at 12:15 pm
Please someone help me. Was the snow green during the medieval warming period when the Vikings named it gruenelande? Dumme verschlachtekopffe!
Or New England as Vinland (Vine Land due to all the grapes they found there)
KR says:
April 5, 2012 at 1:21 pm
Sorry for being so hasty. I did not realize that you had posted your estimate. Let’s assume that your estimate of sea-level rise is more accurate than those by others. You could be right, and all of the others could be wrong. As you say, “One meter of sea level rise by 2100 is entirely possible…”, but then it is also entirely possible that if the warming is that pronounced that a lot of the extra melt water will evaporate, turn into clouds, increase the albedo and cause the start of the next ice age…
I don’t see your estimate taking that into account, but there is no doubt in my mind that you must do so.
eric1skeptic, Bill Yarber – references?
jorgekafkazar – Varies with location. But keep in mind that any tide or tsunami differences will be differentials from the base sea level. So take any existing differential and add the sea level rise on top of it.
Walter H. Schneider – Melt contribution of half a meter, plus thermal expansion (currently running about equal in scale), leading to perhaps ~1 meter of sea level rise by 2100. Looking at some maps (http://flood.firetree.net/), that means most of the islands in the Chesapeake Bay, goodly chunks of the Florida Keys and Cape Hatteras, say goodbye to New Orleans, certainly parts of Bangladesh and other low-lying countries… I would consider that noticeable. Wouldn’t you?
@KR
Welcome back. Always glad to see you are taking notice how the CAGW campaign crashes and burns faster than an Ontario barn on a Halloween night.
Please let me explain something for you:
There can be no doubt that the melt rate of the Greenland ice sheet is variable. I for one hope it disappears completely because that will mean the Arctic will be habitable again, the trade routes will open fully across the Arctic Ocean, the forests will be re-established at once again across the endless stretches of Northern Canada where they once stood before the big freeze came and killed them all. The trees are already there, stunted to a couple of feet by the ghastly freezing winds belting across the tundra. Farming will return to the fertile plains of Greenland. The vast Mackenzie Valley and well-watered Delta will turn into a breadbasket with day-long sunshine and a temperate climate. The absorption of CO2 will be massive, gigantic, similar to the creation of a second Amazon forest.
Will this melting be brought about by human emissions of CO2? Not a chance! For two reasons: first, there is not enough accessible carbon on the planet to make such a significant difference, so weak is carbon dioxide’s effect as a GHG, as numerous peer reviewed scientific publications indicate, should you care to look.
Second, and more relevant to today’s topic: because all that melting ice has nearly no CO2 in it. Sea water contains about 0.03% CO2. That means the melt water from Greenland alone – 5 million cubic kilometers will absorb 1.56 x 10^12 tons of CO2 just to bring it in balance with the present CO2 level in the ocean – not including any Antarctic melting, if the present ice mass growth reverses.
It is simple facts like this which the public is not told about: 1,560,000,000,000 tons of CO2 would be absorbed by the water just from a melted Greenland ice sheet. That is equal to the total emissions from burning 410,000,000,000 tons of carbon or roughly 500 billion tons of good quality dry coal. Were that much coal to be found, and were it to be burned over a period any number of years, the CO2 level in the atmosphere would remain exactly where it is and the ocean pH would not budge at all, so great is the absorbing power of sea water. The faster it melts, the faster the CO2 would be extracted from the atmosphere. If an equal amount of melting took place from Antarctica, the absorption would be doubled to 3.12 trillion tons of CO2 with no change in atmospheric concentration.
Consider that all the rest of the ocean might also absorb a little more as well. The ocean’s capacity to absorb CO2 is huge and the pH buffering capacity is massive almost beyond the counting of it. Thus the possibility of the humble human race doubling the CO2 concentration in the atmosphere is approximately zero, even in a thousand or five thousand years.
The fact that the melting rate does not match the present emission rate of the oceans and mankind is not very important because it will catch up. As there is no clear relationship between the CO2 level and the temperature (which is the Big Fear) one cannot say with any certainty the world will heat up at all, let alone ‘catastrophically’. All indications are we are now headed into a long period of cooling which is a threat to food and comfort that will peak just as the human population does in 2050. The future just ain’t what it used to be.
You’re welcome.
KR
The is no validity in taking one or two years of data, then extrapolating a fabricated melt rate trend 90 years into the future. You have no reliable data that enables you to make a credible claim that a 1 m sea level rise is even possible in that time frame. Nor does anybody else.
For those who want to know how the calculation above relates to the total mass of CO2 in the atmosphere, see http://micpohling.wordpress.com/2007/03/30/math-how-much-co2-by-weight-in-the-atmosphere/
The answer is 3 x 10^12 tons. If the melt water from the whole of Greenland and a similar amount were to melt from Antarctica, it would mean we would have to emit the equivalent of 2 times the present CO2 load in the atmosphere to keep the current 392 ppm constant because the meltwater would start absorbing CO2 like mad.
If the Greenland ice sheet were really melting, wouldn’t Greenland be as the weight of the glaciers decrease?
“The Greenland ice sheet will lose a bit more than 0.4% of its ice volume.” That’s in total over the entire 90 years. The 0.005% is per year, right?
And KR, your math is all wrong.
If we add in 10% of the melt per year, then it’s just 10% more at 0.44% for the entire 90 years.
Without the 10%, it’s 5.75 cm rise in oceans, not half a meter. That’s nothing. With 10%, its 6.3 cm. oh noes.
Oops! It is late at night here in Gotham South.
” …it would mean we would have to emit the equivalent of 2 times the present CO2 load in the atmosphere… ”
Correction: “…we would have to emit the equivalent of the present CO2 load in the atmosphere….”
The study by the brilliant South African Willem Nel into how much we might be able to increase the CO2 concentration with known and estimated carbon-rich sources shows that we are unlikely to be able to drive up the atmospheric concentration an additional 150 ppm, and he did not consider the absorption of CO2 by new sea water.
During Atlasgate http://www.nytimes.com/2011/09/25/science/earth/25atlas.html?_r=1
Dr Curry invited a Glaciologist to discuss with us some of the claims.
I had the opportunity to ask about this.
“WWII plane recovered in Greenland
A World War II US fighter plane once entombed under 100 metres of snow and ice in Greenland is back in the skies to complete a mission it began nearly 65 years ago.
Dubbed “Glacier Girl” after being recovered, the P-38 fighter left Teterboro Airport in the United States for another leg of a journey to Duxford, England, where it is scheduled to land on June 29.”
http://www.smh.com.au/news/World/WWII-plane-recovered-in-Greenland/2007/06/23/1182019412243.html
My question is / was doesn’t this mean during the 1940’s there was a lot less ice on Greenland?
It [ my q ]still goes unanswered.
C’mon guys, we should go easy on Mr. Israel . . . he’s a “journalist” so arithmetic is very, very difficult.
The only thing disappearing in this instance is his credibility.
Can someone answer this simple validation test (required for all models in science). If CO2 is increasing and atmospheric water is decreasing, isn’t the model in accurate and therefore CO2 is not driving increasing temps? My understanding is CO2 causes some warming, that causes more atmosphere H20 which forces the majority of warming.