Greenland ice cap melting faster than ever

Nov 12, 2009
Greenland ice cap melting faster than ever
A glacier off the coast of Greenland. Photo by Jonathan Bamber

Satellite observations and a state-of-the art regional atmospheric model have independently confirmed that the Greenland ice sheet is loosing mass at an accelerating rate, reports a new study in Science.

This mass loss is equally distributed between increased iceberg production, driven by acceleration of Greenland's fast-flowing outlet glaciers, and increased meltwater production at the ice sheet surface. Recent warm summers further accelerated the mass loss to 273 Gt per year (1 Gt is the mass of 1 cubic kilometre of water), in the period 2006-2008, which represents 0.75 mm of global rise per year.

Professor Jonathan Bamber from the University of Bristol and an author on the paper said: "It is clear from these results that mass loss from Greenland has been accelerating since the late 1990s and the underlying causes suggest this trend is likely to continue in the near future. We have produced agreement between two totally independent estimates, giving us a lot of confidence in the numbers and our inferences about the processes".

The Greenland ice sheet contains enough water to cause a global sea level rise of seven metres. Since 2000, the ice sheet has lost about 1500 Gt in total, representing on average a global sea level rise of about half a millimetre per year, or 5 mm since 2000.

At the same time that surface melting started to increase around 1996, snowfall on the ice sheet also increased at approximately the same rate, masking surface mass losses for nearly a decade. Moreover, a significant part of the additional meltwater refroze in the cold snowpack that covers the . Without these moderating effects, post-1996 mass loss would have been double the amount of mass loss observed now.

Source: University of Bristol (news : web)

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Canman
Nov 12, 2009
This comment has been removed by a moderator.
x646d63
3.4 / 5 (13) Nov 12, 2009
@Canman: Demonstrate for us naysayers that short-term acceleration of melting of the Greenland ice sheet is the direct result of AGW.
Canman
2.5 / 5 (16) Nov 12, 2009
There you are!
If I ate dirt, and then puked, would you ask me to demonstrate that the dirt made me puke? No. The burden of proof is on the one who doubts the glaringly obvious. If I pump megatons of a known greenhouse gas into the atmosphere and it starts to get hotter, then I ask you: show me that the warming is not caused by the greenhouse gas.
edwardm
2.9 / 5 (16) Nov 12, 2009
The burden of proof is on the one who doubts the glaringly obvious.


Hahahahahahah! The world is indeed in very bad shape - not from global warming but from naive, gullible people like yourself who blindly follow politicians and the media.

The world has entered a cooling period for the past decade. Last month was one of the coldest on record. The proof is not much of a burden...take a walk outside and use your senses.
Ronan
3.1 / 5 (15) Nov 12, 2009
EdwardM, take a look at the worldwide temperature record sometime; even for just the last century'll do fine. Notice that the current "dip" in global temperatures (not exactly a dip, really; temperatures are still rising, just not as precipitously as they were for a brief period pre-1998) is certainly not unprecedented in the last century of temperature increase. There've even been longer and more dramatic periods of little temperature rise, or even of temperatures dropping (~1940-~1970, anyone? 1980-1985?)--and yet, the overall temperatures just keep rising. I'm not going to take a decade/half decade of less-dramatic temperature rise as the all-clear sign. Mind, if temperatures were to drop significantly for decades on end, or drop more steeply in a shorter period of time, then I'd think there might be something amiss. But as things are...
Ronan
3.3 / 5 (15) Nov 12, 2009
...Um, yes. Anyway, in re the article itself, although the contents are worrying enough (great. EXACTLY what we needed), it's heartening to see that we've got a decent enough grasp on the major processes involved that the observations made by the satellite were predicted by the model. Errors were present, I'm sure, but...we've come a long way from the first few crude, simplistic models decades ago, really.
dmcl
3.7 / 5 (9) Nov 12, 2009
accelerating melt during a dip in the rate of warming. Now that is something worth paying attention to
Canman
2.5 / 5 (11) Nov 12, 2009
This idea that we are no longer warming is bunk. Please see the following:http://www.cbsnew...35.shtml
wiserd
3.7 / 5 (9) Nov 12, 2009
"and the underlying causes suggest this trend is likely to continue in the near future"

What underlying causes? The radiosonde data (pre-"correction") shows no warming of the troposphere which is a crucial requirement of greenhouse warming. Recently, the IPCC announced that it didn't even have its raw data set, making its work entirely non-peer reviewable (and thus non-scientific.) Such a gaffe is simply staggering.

Incidentally, the increase in a few ppm of CO2 were never, by themselves, enough to cause significant global warming (though increased carbolic acid in the ocean may be problematic.) AGW required a forcing effect from increased atmospheric H2O to magnify it.

Also, if you remove a glacier from a continent there's going to be some continental rebound, which will mitigate the effect on sea level, similar to how an ice cube melting in a cup of water does not raise the water level. Doubly so for any glaciers which were not over land to begin with.

malapropism
2.6 / 5 (8) Nov 12, 2009
@Canman: Demonstrate for us naysayers that short-term acceleration of melting of the Greenland ice sheet is the direct result of AGW.

But does it really matter what it is directly attributable to? It seems incontrovertible from this research that the Greenland ice sheet is melting at an accelerating rate - you don't appear to be in denial of this (and if you are, you should present your research results to counter those reported).

This melt could be caused by global warming - it appears to be the case, viz. "Recent warm summers further accelerated the mass loss". This may or may not be a long-term trend. Global warming may or may not be caused by human activity. Time will tell on both of these.

If we think we are causing it and take counter measures but it turns out we weren't causing it after all, where's the harm exactly? And are you prepared to take the alternative risk? (Do you live in a low-lying area? I'd be a little worried if I did, regardless of cause.)
elgin
3.8 / 5 (12) Nov 13, 2009
Didn't Greenland melt once before? Enough so that people colonized it and named it GREENLAND? And if I remember correctly, the melting of Greenland was not followed by catastrophy. It was followed by a Mini Ice Age. Please explain.

I also note that Physorg had an article 2 months ago which stated that loss of Greenland's ice mass was slowing.

http://www.physor...271.html

Again, please explain.
wiserd
3.8 / 5 (10) Nov 13, 2009
"If we think we are causing it and take counter measures but it turns out we weren't causing it after all, where's the harm exactly?"

If it were a matter of supporting and streamlining nuclear power, supporting nuclear fuel reprocessing, advancing fusion research and iron fertilization of the earth's oceans "dead zones", I'd agree with you. These are directions we would justifiably go anyways. The problem is that the 'countermeasures' often involve hundreds of billions of dollars of inefficiency introduced into the economy and dramatically increased, internationally regulated control of the world's economy. Enron was a huge proponent of the carbon vouchers trading scheme, and there are going to be people making a lot of money for no added productivity from such a setup.

If we are facing a high likelihood of a catastrophe that will wipe out most of the human race, then such measures are reasonable. But most indications are that this simply isn't even a remotely probable outcome
thematrix606
3 / 5 (6) Nov 13, 2009
This idea that we are no longer warming is bunk. Please see the following:http://www.cbsnew...35.shtml


Canman, I like how you used this article as fact, seeing as, and this is a direct quote from the article: "In a blind test, the AP gave temperature data to four independent statisticians and asked them to look for trends"

So, no more scientists? Journalist and statisticians will tell us the truth!

/sarcasm
Bob_Kob
3.2 / 5 (9) Nov 13, 2009
"What is verifiable is that the ice cores indicate Greenland has experienced dramatic temperature shifts many times over the past 100,000 years — which makes it possible to say that areas of Greenland may have been much warmer during the medieval period than they are now and that the ice sheet contracted significantly."

Oh no it seems like there was global warming back then! Please eskimos, stop your polluting ways!
Egnite
3 / 5 (8) Nov 13, 2009
This idea that we are no longer warming is bunk. Please see the following:http://www.cbsnew...35.shtml


Yeah Canman, the media tells us so it must be true? Well I was brought up being told never to trust a politician and to take what the media say with a pinch of salt. Since this whole charade started with a politician and has been forced on the public by the media, I assume it whould be taken with a large pinch of salt.

Plus the fact that the best "solution" being spoke at the moment is a tax, doesn't that make you suspicious? How will rich politicians/bankers = less greenhouse gases? It won't, it'll only deter the lower classes from burning energy and cost the middle classes. A simple change in legislation would do more good than a CO2 Tax ever will yet this is the road they seem to be heading down yet you follow without question, wake up ffs!
Canman
2.7 / 5 (7) Nov 13, 2009
Wiserd, funny that you are ready to believe that Greenland will just "pop up" once the ice on it melts, but you are not ready to believe that pumping stadium loads of greenhouse gas into the air could warm the place up.
Maybe your right; thousands of the worlds top scientists who have been trained in seeking the truth their adult lives have all just suddenly become confused, or worse, are all conspiring to obtain more grant money by making it sound like the end of the world is near (even though they already have tenured, cush jobs).
Canman
2.7 / 5 (7) Nov 13, 2009
Egnite,
I think maybe you are confusing "politician" with "statistician". It's ok to trust the statisticians, they have nothing to gain by fooling you.
As far as trusting the media, wasn't that the purpose of commisioning several independant statisticians? Remove chances of bias or collusion?
At any rate, I have a feeling you believe the media more than you think. Did you only believe 9/11 happened when you talked to a personal witness or you travelled to see for yourself. Do you really know who the president is right now?
Canman
2.7 / 5 (7) Nov 13, 2009
Bob Kob,
We are not suggesting that the temperature has been constant for the last 100,000 years. We are suggesting that the current warming is in part due to human activity.
By the way, if there was anthropogenic global warming in the middle ages, it was likey from the deforestation of what is now modern Europe. (digging up forests releases alot of co2).
extropian58
5 / 5 (3) Nov 13, 2009
The burden of proof is on the one who doubts the glaringly obvious.


Hahahahahahah! The world is indeed in very bad shape - not from global warming but from naive, gullible people like yourself who blindly follow politicians and the media.

The world has entered a cooling period for the past decade. Last month was one of the coldest on record. The proof is not much of a burden...take a walk outside and use your senses.


I suppose that "proof of the senses" would call into question the theory of the spherical earth and the heliocentric theory as well. Ah well, they are only "theories", right?
Caliban
2.7 / 5 (6) Nov 13, 2009
Controversy regarding the "AG" part of global warming aside- the salient point here is that the average global temperature is increasing, and if it continues, almost certainly icecaps and glaciers will continue to melt, probably at an accelerating rate. It is estimated that the icesheet of Greenland alone will raise sea level by approximately 7 metres. this equates to MASSIVE inunundation in a matter of DECADES, especially along coastal plains and river valleys/estuaries. At the same time, the bulk of most of the world population inhabit these same areas and a huge percentage of agriculture is also practised there. Where do these people go, and how do you replace the food supply?
defunctdiety
2.3 / 5 (3) Nov 13, 2009
the current warming is in part due to human activity

Actually, AGW is pretty clear and emphatic in stating that the past, current and future warming trend is entirely due to human activity. Anthropogenic, beginning in humans.

The viability of the notion that we can do anything to ameliorate global warming with carbon shuffling depends on this assertion.

You are really the first AGW proponent I think I've ever heard even mistakenly suggest that there could be something else playing a part besides CO2. This is obviously because once that ground is given it must be demonstrated how man's role is quantified and that we have quantified all other factors, and when no one can, everyone will realize what shaky ground the AGW house of cards stands on.
Ninderthana
2.3 / 5 (3) Nov 14, 2009
Doubling of CO2 - even global warming alarmists agree that this will only lead to a 0.6 C increase in world temperature.

The models used by the IPCC require positive feedback from H20. Themodel are built on the premise that relative humidity in the upper tropical troposhere remains constant as the air warms [i.e. the specific humidity - mass of H20 per kg of air] increases].

One minor problem! The specific humidity of the upper tropical troposphere has been systematically decreasing over the last 50 years.

Net outcome: NO CO2-induced global warming.

End of arguement.
fixer
not rated yet Nov 14, 2009
Not really, While you hotheads are arguing the tide has been comming in.
Have you been down the beach lately?
Instead of quoting others why not look for yourselves, try talking to people who live in coastal areas and tell them that the sea isn't rising.
Has anyone seen Tu Valu lately?
wiserd
3 / 5 (2) Nov 15, 2009
Canman -

I am "ready to believe" that increasing CO2 by a few ppm could warm the environment significantly, given evidence. Lack of tropospheric warming, however, indicates that this isn't the predominant cause of the current warming. Or do you have some entirely new model for CO2 increasing atmospheric H2O (which is required for significant warming) leading to greenhouse warming that does not involve tropospheric warming?

Similarly, increases in sea levels have been much more modest than predicted. If you'd like to contribute an alternative theory for why, go ahead. But continental rebound is an observed trend.
http://en.wikiped...rebound.

So yes, sea levels are rising to an extent, but not near the rate previously predicted.

Scientists are not a priesthood, nor should we trust them if they were. If the IPCC's data is not peer reviewable, and it is not, then what they are doing is not science, plain and simple.

Nartoon
3 / 5 (2) Nov 16, 2009
OMG! It's worse than we thought!

Man made CO2 is only responsible for 3-4% of all the CO2 generated in the world each year. The world wide CO2 is rising about 1-2 ppm a year, 3-4% of this is 0.03-0.06 ppm. If we cut the man made CO2 by 100% the earth would only warm by 0.01°C in 100 years, by then we'll all be dead, and whatever was going to happen will have happened unless you can figure out how to stop the 96-97% of CO2 that isn't man made!
GrayMouser
not rated yet Nov 26, 2009
I think the main point is that, as during the MWP, beach front property and dairy lands will be affordable again. A new land rush... Well a rerun of a 1000 year old land rush anyway.