|
Post by louise on Mar 1, 2011 20:22:12 GMT 1
How fast were they going before? If thet are going faster, could it be because there is a greater mass pressing downhill? They are now going twice as fast as before (see original link) and the mass is now greatly reduced (see www.skepticalscience.com/Various-estimates-of-Greenland-ice-loss.html ) Three different studies using different methods - same result.
|
|
|
Post by marchesarosa on Mar 2, 2011 2:26:43 GMT 1
Unless we were going into another glaciation or in a state of climate stasis you would EXPECT the world's ice to be melting just as it has for the twenty thousand years of the current inter-glacial. You know what an interglacial is, I suppose? It is one of those brief windows in geological time when the Earth becomes a pleasant place to live between the very cold and nasty climate which has been the norm for several millions years. The Earth is, in fact, in "ice-house" mode but is going through one of its periodic respites for which we should be profoundly grateful. When ice stops melting is the time to worry. The world's oceans have risen, I believe, 400 feet since the end of the last glaciation. It seems a bit late in the day to start worrying about millimeters, Louise. It would be interesting to understand what causes it but hardly of over-riding importance in the scheme of things to worry about. Variations in the rate of change of ice-melt, and I am not convinced that it is actually possible to make meaningful estimates or comparisons on the recent very short timescale you have mentioned, happen for reasons about which little is known - except that temperature variation is involved. So what causes the temperature to vary? Interesting question that should not be begged. See this historical archive which goes back a little further than the "satellite" era to get a better perspective on Arctic ice-melt. radio4scienceboards.proboards.com/index.cgi?board=witter&action=display&thread=599You should read it at least once a week, Louise, to calm your obvious anxiety about the sea-level. There is sod all to be done about it except adapt.
|
|
|
Post by marchesarosa on Mar 2, 2011 2:56:52 GMT 1
See also Willis Eschenbach's amusing piece on "gigatonnes". Size matters, or does it? Hundreds of Gigatones of ice melt per annum sounds an awful lot but how much is that as a proportion of the TOTAL sitting on Greenland? Do you know, Louise? Not so very large as a proportion, in fact. Greenland has an estimated volume of 3 million cubic kilometers of ice-cap plus or minus the odd half million cubic kilometers. The figures you quote for annual melt, whether accelerating or not, is a miniscule fraction of the total. Willis argued, "This means that Greenland is losing about 0.007% of its total mass every year … seven thousandths of one percent lost annually, be still, my beating heart …
And if that terrifying rate of loss continues unabated, of course, it will all be gone in a mere 15,000 years....
That’s my pet peeve, that numbers are being presented in the most frightening way possible. The loss of 200 km^3 of ice per year is not “some of the most powerful evidence of global warming”, that’s hyperbole. It is a trivial change in a huge block of ice.
...meaningless numbers with no errors presented for maximum shock value. Looking at the real measure, we find that Greenland is losing around 0.005% — 0.008% of its ice annually, and if that rate continues, since this is May 23rd, 2010, the Greenland Ice Cap will disappear entirely somewhere between the year 14010 and the year 21010 … on May 23rd …"wattsupwiththat.com/2010/05/23/on-being-the-wrong-size/
|
|
|
Post by eamonnshute on Mar 2, 2011 9:50:37 GMT 1
"This means that Greenland is losing about 0.007% of its total mass every year … seven thousandths of one percent lost annually, be still, my beating heart …
And if that terrifying rate of loss continues unabated, of course, it will all be gone in a mere 15,000 years....
That’s my pet peeve, that numbers are being presented in the most frightening way possible.
If you think that is the most frightening way to present the figures then consider this. Until about ten years ago the ice loss was zero. Since then the rate of loss has been increasing every year. So if this continues, within one hundred years the rate of loss will be ten times greater, and that reduces the life of the ice from 1500 years to less than 1500 years. But why should it stop there? Warming is expected to continue beyond 2100. Where will it end? It is hard to make predictions 100 years into the future, but if things continue as at present then the ice will be gone in very much less than 15,000 years.
|
|
|
Post by marchesarosa on Mar 2, 2011 10:04:41 GMT 1
"Until about ten years ago the ice loss was zero"
This is a nonsensical statement that goes against the accumulated evidence of the evolution of ice on this planet. Sea level on Earth has risen about 400 feet since the depths of the last glacial. This is due to melting ice and thermal expansion and probably some other influences as well.
Do try to keep your comments SENSIBLE, Eamonn, please.
Nice to see you back amongst your pals, though, Eamonn and Louise, or are they your clones?
You are right, Eamonn, "It is hard to make predictions 100 years into the future" and it is stupid to make linear extrapolations of purported short term variability that we have not even got the hang of measuring - see previous discussion of the GRACE satellites' "measurements" at posts #18 #24 and #26
"Measurements" is too precise a word, actually, for what the "interpreters" of the GRACE data are doing!
|
|
|
Post by eamonnshute on Mar 2, 2011 10:39:23 GMT 1
Have a look at my crib sheet, particularly figure 3, which shows that the rate of melting was zero till around 2000. Perhaps you would like to tell us what would happen if it continues to accelerate. how long will the ice last, assuming the most OPTIMISTIC reasonable assumptions? www.skepticalscience.com/Various-estimates-of-Greenland-ice-loss.htmlIn other words, sea level is very sensitive to changes in temperature, so good reason to be worried. The crib sheet shows that 3 different measures give consistent results. So they seem to be getting it right.
|
|
|
Post by rsmith7 on Mar 2, 2011 11:05:18 GMT 1
Take your eco-propaganda snd shove it where the sun doesn't shine, eamonn. The CAGW myth is exposed. Keep up.
|
|
|
Post by louise on Mar 2, 2011 11:24:12 GMT 1
So when you can't refute the science, you resort to aggresive insults.
Why not try to refute the science instead?
|
|
|
Post by rsmith7 on Mar 2, 2011 11:56:14 GMT 1
I'm bored with repeating the same arguments with zealots.
|
|
|
Post by louise on Mar 2, 2011 12:04:52 GMT 1
I'm bored with repeating the same arguments with zealots. Perhaps that's because the overwhelming body of evidence does not support your arguments? Otherwise, we'd all believe as you do wouldn't we?
|
|
|
Post by marchesarosa on Mar 2, 2011 12:06:49 GMT 1
"I'm bored with repeating the same arguments with zealots".
Yes, but do try to humour them, in the interests of board harmony, Mr Smith.
|
|
|
Post by marchesarosa on Mar 2, 2011 13:19:38 GMT 1
"sea level is very sensitive to changes in temperature"
Both up and down, Eamonn, if the geological record is to be believed. But well-spotted, anyway, old chap!
|
|
|
Post by rsmith7 on Mar 2, 2011 14:11:19 GMT 1
I'm bored with repeating the same arguments with zealots. Perhaps that's because the overwhelming body of evidence does not support your arguments? Otherwise, we'd all believe as you do wouldn't we? But it just doesn't....especially if you discount the government sponsored, pseudo-science that underpins your beliefs.
|
|
|
Post by rsmith7 on Mar 2, 2011 14:13:10 GMT 1
"I'm bored with repeating the same arguments with zealots". Yes, but do try to humour them, in the interests of board harmony, Mr Smith. Sorry - a symptom of an extremely heavy workload, I'm afraid.
|
|
|
Post by marchesarosa on Mar 2, 2011 19:08:26 GMT 1
|
|