No mention of missing “M’s” here in this press release from University of Melbourne
Melting sea ice has been shown to be a major cause of warming in the Arctic according to a University of Melbourne study.
Findings published in Nature today reveal the rapid melting of sea ice has dramatically increased the levels of warming in the region in the last two decades.
Lead author Dr James Screen of the School of Earth Sciences at the University of Melbourne says the increased Arctic warming was due to a positive feedback between sea ice melting and atmospheric warming.
“The sea ice acts like a shiny lid on the Arctic Ocean. When it is heated, it reflects most of the incoming sunlight back into space. When the sea ice melts, more heat is absorbed by the water. The warmer water then heats the atmosphere above it.”
“What we found is this feedback system has warmed the atmosphere at a faster rate than it would otherwise,” he says.
Using the latest observational data from the European Centre for Medium-Range Weather Forecasting, Dr Screen was able to uncover a distinctive pattern of warming, highly consistent with the loss of sea ice.
“In the study, we investigated at what level in the atmosphere the warming was occurring. What stood out was how highly concentrated the warming was in the lower atmosphere than anywhere else. I was then able to make the link between the warming pattern and the melting of the sea ice.”
The findings question previous thought that warmer air transported from lower latitudes toward the pole, or changes in cloud cover, are the primary causes of enhanced Arctic warming.
Dr Screen says prior to this latest data set being available there was a lot of contrasting information and inconclusive data.
“This current data has provided a fuller picture of what is happening in the region,” he says.
Over the past 20 years the Arctic has experienced the fastest warming of any region on the planet. Researchers around the globe have been trying to find out why.
Researchers say warming has been partly caused by increasing human greenhouse gas emissions. At the same time, the Arctic sea ice has been declining dramatically. In summer 2007 the Arctic had the lowest sea ice cover on record. Since then levels have recovered a little but the long-term trend is still one of decreasing ice.
Professor Ian Simmonds, of the University’s School of Earth Sciences and coauthor on the paper says the findings are significant.
“It was previously thought that loss of sea ice could cause further warming. Now we have confirmation this is already happening.”
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It is very interesting to speculate on the reasons for melting but we should not believe that this is a unique event. Whatever the causes this time round, it must be stressed yet again that the arctic ice melts with surprising regularity. The Ipiatuk 2000 years ago and the Vikings 1000 years ago both had substantially greater ice free seas than at present.
In what can be described as the modern era we can trace two periods of considerable melt. The authors own study demonstrated a surprisingly warm period recorded in the arctic around 1815-1860
http://wattsupwiththat.com/2009/06/20/historic-variation-in-arctic-ice/#more-8688
There is further evidence of substantial 1920-1940 warming in the Arctic –many of whose records remain unsurpassed even today. This period is very well documented as expeditions there to view the melting ice became the equivalent of todays celebrity jaunts to the area. The most famous were those mounted by Bob Bartlett on the Morrissey. One memorable diary extract describes his observations of the mile wide face of a glacier falling in to the sea.
http://boothbayharborshipyard.blogspot.com/2008/08/arctic-explorer-on-ways.html
“Wednesday, 10th August 1932
The ship rolled heavily all night and continues to do so….
The glacier continues its disturbances. No real bergs break off but great sheets of ice slide down into the water and cause heavy seas. About noon, the entire face of the glacier, almost a mile in length and six or eight feet deep slid off with a roar and a rumble that must have been heard at some distance. We were on deck at the time for a preliminary report like a pistol shot had warned us what was coming. The Morrissey rolled until her boats at the davits almost scooped up the water and everything on board that was not firmly anchored in place crashed loose. But this was nothing to the pandemonium on shore. I watched it all through the glasses. The water receded leaving yards of beach bare and then returned with a terrific rush, bringing great chunks of ice with it. Up the beach it raced further and further, with the Eskimos fleeing before it. It covered all the carefully cherished piles of walrus meat, flowed across two of the tents with their contents, put out the fire over which the noonday meal for the sled drivers was being prepared, and stopped a matter of inches before it reached the pile of cement waiting to be taken up the mountain. Fortunately, in spite of heavy sea, which was running, the Captain had managed to be set shore this morning so he was there with them to help straighten out things and calm them down.”
There are pathe news reels of his voyages which your grandparents may have watched at the cinema in the 1930’s, and books on the subject.
Here is a bibliography of material relating to him.
http://www.nlpubliclibraries.ca/nlcollection/pdf/guides/NL_Collection_Guide_11.pdf
These are two technical examinations of the 1920 arctic
ftp://ftp.whoi.edu/pub/users/mtimmermans/ArcticSymposiumTalks/Smolyanitsky.pdf
http://meteo.lcd.lu/globalwarming/Chylek/greenland_warming.html
This free online book by Dr Arnd Bernaerts examines the last great warming -prior to the modern one- in great detail.
Article: Arctic warming 1919-1939. Author: Dr Arnd Bernaerts
http://www.arctic-heats-up.com/chapter_1.html
The Monthly Weather Review for November 1922 contained a fascinating record of this warming arctic early on in the melting. It sounds uncannily like the appeal from the Whalers to the Royal Society in 1817 to find out why the arctic was melting as mentioned in my article linked to previously.
* http://docs.lib.noaa.gov/rescue/mwr/050/mwr-050-11-0589a.pdf
Tonyb
It appears that the extent of the Arctic ice is directly governed by the deep warm waters of the Gulf current. Just compare these two maps:
http://www.vukcevic.talktalk.net/LFC15.htm
If so than the ocean conveyor belt is in the charge.
http://climate.nasa.gov/kids/images/ocean_currents.jpg
So the Arctic is warming due to positive feedback effects yet the ice is increasing at the same time. Well done, Alarmist Class 101.
You know, if I were the paranoid, tin-foil hat wearing type, I might be thinking thoughts such as “Hrm, perhaps there is now a concerted effort to feed lots of AGW-supporting peer-reviewed papers into the system, so that the next IPCC report can cite them all”.
Fortunately, I’m not that type of person. I mean, this couldn’t possibly be the case, could it? No one group of people could be that sneaky, could they?
Oh, wait…
“Findings published in Nature today reveal the rapid melting of sea ice has dramatically increased the levels of warming in the region in the last two decades.”
Okay, so the rapid buildup of ice since 2007 now should dramatically increase the level of cooling then?
Or?
That must mean the “increased the levels of warming in the region” nowadays is from “The hidden ‘M’.
Or maybe its “The Dark Heat” they are talking about.
[quote Martin Brumby says:]
But are you sure it is Dr. Screen, Anthony?
[/quote]
Yes, it’s Dr. Screen. I’m familiar with his work. He invented a type of door for a submarine that is named after him.
But sea ice reduction is due to wind pattern, not melting. Just in yesterday: A Norwegian study that confirms the wind theory. The headline: “Ice extent a poor climate indicator”.
See: http://www.forskning.no/artikler/2010/april/248227
Google translate: http://translate.google.com/translate?js=y&prev=_t&hl=en&ie=UTF-8&layout=1&eotf=1&u=http%3A%2F%2Fwww.forskning.no%2Fartikler%2F2010%2Fapril%2F248227&sl=no&tl=en
ICCP measurements show that low cloud cover has decreased in the Arctic. This causes more sunlight reaching the surface and more melting of ice in the Arctic summer. With less ice cover, the increased amount of sunlight can warm even more ocean water. The water then warms the lower atmosphere. There is no need to introduce any increased greenhouse effect to explain what has happened in the Arctic the last decades. The decrease in low cloud cover started it all and is the only explanation needed.
This makes some kind of sense as an ongoing process, but poses a bunch of questions, including:
1) precisely what started it? Could changing cloud cover patterns have been the crucial factor?
2) if the trend has started to reverse – which is possible – then what, precisely, has happened to cause the change of direction?
3) If significant warming has been occurring in the Arctic in the last nine years when global temperatures as a whole have been stable, does that mean that there has actually been global cooling in the non-Arctic area of the globe?
So what caused the 1.5-2 deg arctic warming between 1910-1940. According to GISS the magnitude of the 1910-40 warming is almost identical to the warming over the last 30 years.
I have no reason to doubt the GISS record.
I think young Dr Screen who graduated as a Doctor of Philosophy from the University of East Anglia has been well trained from a region that seems to specialise in proving theories given a set agenda.
But from the accent and the video clip:
http://newsroom.melbourne.edu/studio/ep-72
I believe he should have stuck to poems like Pam Ayres such as “Oh I wish I’d looked after me teeth” rather than getting involved in climatology:
Let’s not condemn this study too quickly. If melting causes arctic warming, and soot causes melting, then soot causes arctic warming — not CO2.
“What we found is this feedback system has warmed the atmosphere at a faster rate than it would otherwise,”
Otherwise? This is a comparison, no? So, where is the comparitor, the control located? Or is it, as is becoming a wearying familiarity, another ‘sophisticated’ computer model?
I see the BBC has decided to run with this, although merely reprinting a summary statement is a poor return on the license fee. Sadly, contrary to popular fantasy the BBC has never been a fearless or well informed interlocutor or investigator.
I read about this in my local Paper of Stupid this morning, the Sydney Morning Herald. The SMH is totally in the bag as far as global warming is concerned, so they beat the story up even further.
http://www.smh.com.au/environment/climate-change/melting-ice-makes-the-arctic-a-vicious-circle-20100429-tssb.html
I almost spat my coffee out with laughter when I read the final paragraphs:
The amount of Arctic sea ice was at a record low in the summer of 2007, down about 40 per cent.
Although it has recovered slightly since, the long-term trend is down, he said. “We’re heading towards a situation where the Arctic Sea will be ice-free in summer.”/
Last week, we found out a change of winds caused the recent melting of ice (or rather, the pushing of ice into warmer waters south, thus effectively melting them)…. (“A” causes “B”)
Today, we learn that melting ice causes warmer temperatures… (“B” causes “C”). (I’m not disputing whether it’s true.)
So… if A causes B, and B causes C…
The conclusion: The change in winds is driving up temperatures in the Arctic. No?
So why did the winds change recently? Any guesses?
Surely there’s a tree-ring thawing in a bog somewhere which will show (via statistical magic) how my EasyJet flight to the south of France directly caused the winds to change in the Arctic.
…I put a few icecubes in my mug to keep the coffee warm but it didn’t work, the coffee was cold.
Any idea what went wrong probably?
I gave a few icecubes into my mug to keep the coffee warm, but the coffee was cold.
Any idea what probably went wrong?
Hm… And why arctic sea ice extension now is back to nearly normal?
stevengoddard says: April 29, 2010 at 9:24 pm
“20,000 years ago, Chicago and New York were a mile deep in ice. Then the Neanderthals invented the Hummer”
A neat trick considering that the Neanderthals became extinct at least 30,000 years ago!
James H says:
April 29, 2010 at 9:31 pm
“Uh-oh, that means that the increasing sea ice will cause cooling! That may reduce crop output, as well as other problems. It’s worse than we thought!”
So more ice means more reflectance which means more cooling which means MORE ice which means more cooling ……………………. We’re doomed!
This article was featured on the Australian Broadcasting Corporation’s [ ABC ] science site last night.
http://www.abc.net.au/science/articles/2010/04/29/2884900.htm
The taxpayer funded ABC is one of the leading alarmist [ and left wing ] sites in Australia and recently two of their senior executives were revealed as having decided that the ABC would not publish any evidence that contradicted the AGW theory.
And guess who screams loudest if “censorship” of any type is even remotely suggested for the media.
The ABC article referred to the study using satellite data from 1989 to 2008 so the press release above apparently studiously avoids admitting that the data is not up to date and is extremely short term by even climatology standards and could be classified as cherry picked data.
And in fact the whole study has been negated by the rise in Arctic ice areas and volumes in the 2008 / 2009 and 2009 / 2010 northern winters.
The quoted reasons for the supposed decline in Arctic ice are also negated by the latest developments in the Arctic and one of the discarded theories on the forces driving Arctic ice formation and melts seems a far more likely proposition than this “modelled” study by just another government rent seeker.
Why have we become so in awe of people with “Dr” or”Prof” before their names. No disrespect honestly, I have every respct for people who have earned such titles, but Einstien was right on some things, and wrong on others, yet there were people going around saying that he was the most brilliant guy on the planet! He was indeed extremely clever, but not right on every occasion. I recall he thought atomic energy would never be “realised” in around 1931. Then Ernest Rutherford split the atom a year later yet also claimed no energy could be gained from it. How many “Drs” & “Profs” have made immense claims about one thing or another, only to be proven completely wrong within a few months or few years. Dr Screen maybe right, but he may also be wrong. Me thinks a little context & circumspection is needed with a pinch of sodium chloride!
“mark.r says:
April 29, 2010 at 10:59 pm
“but the long-term trend is still one of decreasing ice” HOW DO THY KNOW THIS?.”
Its one of those trivial things that’s always true and hardly worth mentioning. Any trend calculation is always weighted by prior history. If a new data point is above/below the trend the “Long Term” is still in the same direction until the new condition persists long enough to effect the historical weight in the trend calculation.
e.g If your trend measure is 5 year moving average and it currently shows an unhidden decline: If you observe annual increases of the same magnitude as your last decline. they will have to persist for 2 or 3 years to flatten the trend line and longer than that to change its direction.
So yes, its always possible to argue that any small number of values haven’t changed the long term trend, right up until they persist long enough to become inconveniently true. After that you have to appeal to the length of time the observations have trended in one direction and comment on the short duration of the current “Blip”
…we investigated at what level in the atmosphere the warming was occurring… Which dataset it that then? GISS? CRU? We know the data is garbage. Besides that, if you start with a warming atmosphere you will automatically attribute any reduction of ice to it. Conversely, if you start with warmer ocean currents you would attribute the warmer atmosphere to the reduction in ice. What’s cause and effect here? Not a great paper.
And talk about the obvious. Ice is the great big switch in the Earth’s climate. Its presence causes albedo to jump AND evaporation to fall leading to less water vapor in the atmosphere. The southern hemisphere has been in a permanent ice age for millions of years. Anyone looking at the Arctic now would conclude that the northern hemisphere is dangerously close to the next ice age.
I think this is interesting analysis that has drawn the wrong conclusion. The greatest rate of warming is at 90N in the autumn and winter, with a smaller rate of warming as you move south. Surely if the surface temperature amplification is due to diminished sea ice cover, the amplification should be greatest closest to the diminished cover, i.e. at the edge of the ice not at the pole.
I think their conclusion that recent arctic temperature amplification is due to diminishing sea ice cover could equally be interpreted as diminishing sea ice cover is due to recent arctic temperature amplification. However, this would still raise the question of why the amplification is greatest furthest from the melting ice.
The paper: http://sciences.blogs.liberation.fr/files/arctique-ann%C3%A9es-2000-tures.pdf