Old aerial photos supply new knowledge on glaciers in Greenland – it has been warm or warmer than today in the not so distant past

From the University of Copenhagen comes realization that Greenland’s current warm spell is not unprecedented.

In the early 1920s and 1930s, temperatures were high, similar to that of the present, and this affected the glacial melt. At the time many glaciers underwent a melt similar or even higher than what we have seen in the last ten years.

The glaciers in southeast Greenland are retreating rapidly with the ongoing global climate change. But now research from the University of Copenhagen shows that the glaciers can recuperate within a short timeframe if temperatures are to drop. The results are based on a collection of Danish aerial photos combined with both old and modern satellite imagery as well as field work. The scientific results have created international attention and have been published as a cover story in the highly esteemed journal Nature Geoscience.

1930 photo from glaciers in Greenland. Photo credit: Arctic Institute in Copenhagen “We have managed to get an overview of the glacial evolution over a period of 80 years. This is the first time ever this has been done in a study of glaciers in Greenland. Results show that glaciers can recuperate within a short time frame if climate changes and temperatures drop, as it has in a period after the 1940s,” says PhD student and lead-author on the project Anders Bjørk, from Professor Eske Willerslev’s Centre for GeoGenetics from University of Copenhagen.

Anders Bjørk adds:

“Most of the scientific foundation, models, and theories on glaciers in Greenland and how global warming affects them are based on observations from satellites over the last ten years. Otherwise scientists have had to use previous warming events way into the past when wanting to compare today’s massive retreat.”

A fight for land between Denmark and Norway

The Danish explorer Knud Rasmussen and his seventh Thule-expedition in 1932-33 is a significant cause for the recent publication from Anders Bjørk and Dr. Kurt H. Kjær from the Natural History Museum of Denmark, University of Copenhagen. 1930 photo from glaciers in Greenland. Photo credit: Arctic Institute in Copenhagen Results have created international attention as Greenland stands as an important region for northern latitudes are affecting the rest of the earth’s climate – including changes in glacial conditions and related sea-level rise.

Originally the many aerial photos, which have been achieved Danish National Survey and Cadastre, were used for producing new maps of the region in the early 1930s, as Denmark and Norway were fighting over the right of disposal of East Greenland, a fight without casualties which Denmark won at the International Court in Haag in the Netherlands in 1933.

Photos get a renaissanse

With help from the scientists and the Danish National Survey and Cadastre, the unique aerial photos have now gained a renaissance in a different setting where climate change and theories as “The Tipping Point” – where nature reaches a point where changes cannot be reversed are discussed.

1930 photo from glaciers in Greenland. Photo credit: Arctic Institute in Copenhagen“We have investigated no less than 132 glaciers on a 600 km coastal stretch in Southeast Greenland, both those who terminate on land and those who calve in the ocean. The historical photos have proven to be extremely valuable, and with these photos and other aerial photos recorded later during WWII and satellite imagery we are able to observe glacier change in very long historical context. In the early 1920s and 1930s, temperatures were high, similar to that of the present, and this affected the glacial melt. At the time many glaciers underwent a melt similar or even higher than what we have seen in the last ten years. When it became colder again in the 1950s and 1960s, glaciers actually started growing,” says Dr. Kurt H. Kjær and underlines:

“There should be no doubt that if the current temperature rise in Greenland continues then we will have problems with the melting of the glaciers. We are already seeing it now on the marine terminating glaciers where changes in temperature and ocean currents are influencing their stability. Another remarkable discovery we did was that the observed changes are not just local, it is happening in the entire region,” says Dr. Kjær.

Kurt H. Kjær has previously worked with his colleague Svend Funder from Center for GeoGenetics on investigating sea ice extent in the Arctic Ocean. Results showed that the sea ice extent has been far from stable throughout the last 10,000 years.

Read the scientists’ newly published paper in Nature GeoScience .

About these ads

55 thoughts on “Old aerial photos supply new knowledge on glaciers in Greenland – it has been warm or warmer than today in the not so distant past

  1. Headline typo alert:
    s/b “…not too distant past.” or perhaps “…not so distant past.”

  2. Imagine that, the climate has changed, even within recent history. Now imagine my lack of shock that it has. Is. Will.

  3. “In the early 1920s and 1930s, temperatures were high, similar to that of the present, and this affected the glacial melt.”

    Excuse the caps lock shouting:

    AND WHAT, PRAY TELL, CAUSED THAT WARMING, HMM???? WHALE FARTS?

    There are so many indicators of natural variability surrounding the CAGW cult, that they can’t see over them. Yet another example. Ignore history, even when you state its record! It’s enough to drive a man battybonkers.

  4. In elementary school we were taught that clever Viking real estate agents chose the name “Greenland” to lure settlers past the hard to market island of “Iceland”. But the clever Vikings did even more. They carefully planted ruins of 50 cow, stone dairy barns under todays 20 ft thick ice sheets, with distinct Minoan, Roman and Middle Age artifacts to create the APPEARANCE of a warmer past climate. Never trust real estate agents with horned helmets and dragon boats !

  5. Seems I read the other day about Kilimanjaro’s glaciers recovering too. Or maybe it is just a snowcap?

  6. Centre for GeoGenetics?

    Ancient DNA research has progressed from the retrieval of short fragments of DNA from bones to large-scale studies of ancient populations. Through the centre’s multidisciplinary team, novel methodologies, and the access to highly unique specimens and sampling sites, we intend to re-address some of the most highly debated scientific topics in the past decades – carefully chosen in a strong belief, that ancient DNA research can provide fundamentally new insight. Or even shift current paradigms.

    Posted in case you too were wondering just what the heck “GeoGenetics” was.

  7. Faux Science Slayer says:
    May 30, 2012 at 10:50 am
    But the clever Vikings did even more. They carefully planted ruins of 50 cow, stone dairy barns under todays 20 ft thick ice sheets…

    Odd how *fast* a CAGW cultist will change the subject when you bring up those recently-defrosted farms, innit?

  8. If this keeps up we will have to change Disraeli’s comment, “lies, damned lies and statistics.” to
    Lies, damned Lies, statistics and AGW modellers forecasts….
    Folk better start reading up on Leon Festinger’s theories of cognitive dissonance and have big supply of dissonance repair kits (excuses) at hand…

  9. Faux Science Slayer says:May 30, 2012 at 10:50 am

    In elementary school we were taught that clever Viking real estate agents chose the name “Greenland” to lure settlers past the hard to market island of “Iceland”. But the clever Vikings did even more. They carefully planted ruins of 50 cow, stone dairy barns under todays 20 ft thick ice sheets, with distinct Minoan, Roman and Middle Age artifacts to create the APPEARANCE of a warmer past climate. Never trust real estate agents with horned helmets and dragon boats !

    Yes, and as of 2008 there were a total of 29 head of cattle in Greenland, up from 5 head in the year 2000.

    Nowadays they rely on seasonally replanted ryegrass pastures, (and the growing season is still too short for the ryegrass to seed).

    Seems to me, in spite of some charts (eg Moberg etal 2005) telling us it is warmer now in Greenland than it was in the MWP, and that it has been at least as warm there as the MWP was for about the last 140 years, somehow it still seems we are not quite able to replicate the farming practices of those earlier days?

  10. I’m reminded of things that geologists learned after the birth of Surtsey in 1963. That is the volcanic island that literally was born from the sea between November 1963 and June 1967 near Iceland. Entire volumes of how geology worked had to be thrown out and rethought as the scientists watched events happen that they had believed took centuries or longer happen in days and months on the forming island.

    The problem is that events that happen over a very long time are apparently very hard for humans to properly appreciate and even study. Assumptions are always made about what you see now and that it must always have been this way or else it was better or worse than now. Rarely does the fact that systems can operate over long term really connect with our thought. Thus you had geologists who had never seen geology happen in fast time assume that it only happened over long years. The same applies to climate.

    People look at what is now and assume that it has always been this way. Even when you tell them it hasn’t been this way always they still can’t see it. Then something like this happens that brings home for a time that events can be cyclic and what we think are unusual never before seen events are actually just something that happened before.

  11. “In the early 1920s and 1930s, temperatures were high, similar to that of the present, and this affected the glacial melt.”

    Yep. Quick, archive the photographs before GISS photoshops them! :-)

    PS: I think Arctic history is right up Tonyb’s street. Hopefully he can comment.

  12. @rob Honeycutt

    You’re correct, Greenland is just another canary according to the cAGW crowd

  13. It was only a mater of time that air photo archives from the Danes would be found and we would see the truth of cyclical climate change. It was a bit of a bonus though to find there are pre-WWII photos available.

    I wonder if the Canadians have a similar treasure trove of air imagery from their arctic areas. I know from personal experience that there are a lot of 1940’s and 1950’s vertical airphoto archives from further south in the NWT and Yukon. The Technology was extensively used then to produce the first series of acurate topographic maps of Canada’s north.

    I used these photos in the 1970’s and 1980’s to map geology. They were also quite good at showing changes in snow fields and glaciers. I am pretty sure their equvalents exist further north.

  14. Again, this fits in with the opening of the Russian Northern Sea Route Administration (“Glavsevmorput”) in the Arctic Ocean in the 1930s.

  15. on the one hand…they say that glaciers are very fragile and are susceptible to the slightest change

    ..and on the other, they say they are supposed to stay the same

  16. Take a look at slide 5 at the following link. It shows a East Greenland land-terminating glacier Skjoldmøen on Skjoldungen Island in 1943.

    http://www.nature.com/news/rediscovered-photos-reveal-greenland-s-glacier-history-1.10725

    Now take a look at this position in Google Earth (or Maps):

    63°28’58.67″ N 41°43’37.78″ W

    This glacier has only retreated by about 300 meters in 70 years. The glacier has only one tributary and the firn area is only about 16 sq km.It is quite remarkable that so little change has occurred despite the relentless onslaught of back-radiation from man’s evil CO2.

  17. Cui Bono said;
    “In the early 1920s and 1930s, temperatures were high, similar to that of the present, and this affected the glacial melt.”

    Yep. Quick, archive the photographs before GISS photoshops them! :-)

    PS: I think Arctic history is right up Tonyb’s street. Hopefully he can comment.”

    —– ——- ——–

    This article provides many useful bits of evidence of a warmer climate but it is depressing how quickly we forget the past.

    As it happens I am currently writing part two in my series ‘Historic varations in Arctc ice’. It will cover the 1920’s/1930’s warming as well as the seven other major arctic warmings that can be traced through the holocene. There were also numerous lesser warmings, and the jury is still out as to which category the current warming falls into. A constantly changing climate-sometimes warm sometimes cold- was considered the perfectly normal state of affairs until recent decades .

    Here is a short extract from the as yet unfinished and unedited ‘Historic variations in Arctic ice Part two’.covering the period in question;

    —— ——–
    “A bare decade after the loss of the Titanic through crashing into an iceberg that had drifted far to the south of the usual shipping lanes, we can readily see that the nature of the arctic had changed.

    I have tied together two intriguing pieces concerning the Arctic warming from 1918-1939. The first is from British Pathe news reel- which is unfortunately silent- but has the intriguing title;

    “To Prevent Repetition Titanic Disaster – Ice “Patrol” now finds & warns all vessels of location of Icebergs brought down by abnormal heat from Greenland Coast.” It dates from 1922

    http://www.britishpathe.com/video/ice-patrol-aka-to-prevent-repetition-titanic-disas

    This next item relates directly to the various newspaper reports of that same year commenting on the warming, of which this is a good example.

    “The Arctic Ocean is warming up, icebergs are growing scarcer and in some places the seals are finding the water too hot, according to a report to the Commerce Department yesterday from Consul Ifft, at Bergen, Norway.
    Reports from fishermen, seal hunters and explorers, he declared, all point to a radical change in climate conditions and hitherto unheard-of temperatures in the Arctic zone. Exploration expeditions report that scarcely any ice has been met with as far north as 81 degrees 29 minutes. Soundings to a depth of 3,100 meters showed the gulf stream still very warm.
    Great masses of ice have been replaced by moraines of earth and stones, the report continued, while at many points well known glaciers have entirely disappeared. Very few seals and no white fish are found in the eastern Arctic, while vast shoals of herring and smelts, which have never before ventured so far north, are being encountered in the old seal fishing grounds.”

    Note; The source report of the Washington Post article on changes in the arctic has been found in the Monthly Weather Review for November 1922.

    Use the above link-goes direct but may need to enlarge

    This is the complete article from which the above reference comes

    http://docs.lib.noaa.gov/rescue/mwr/050/mwr-050-11-0589a.pdf

    http://www.examiner.com/x-32936-Seminole-County-Environmental-News-Examiner~y2010m3d2-Arctic-Ocean-is-warming-icebergs-growing-scarcer-reports-Washington-Post

    The warming of the arctic was of as much public interest then as it is today, and became the subject of many news items, of which the Pathe news reels already referred to are a rich repository that reached millions of people through their accompaniment to the block buster films of the day.

    Of considerable scientific interest are the voyages of explorers who took advantage of the melting arctic ice, and an unlikely matinee idol of the age was the respected scientific explorer Bob Bartlett who featured in numerous news reels with his ship the ‘Morrissey.

    ‘ Under “Bob” Bartlett, “the little Morrissey” made 20 regular voyages north, at one time reaching within 600 miles of the Pole, documenting the frozen north, its flora and fauna, and people for patrons ranging from the National Geographic Society, the Smithsonian Institution, the Cleveland Museum of Natural History, the Museum of the American Indian, and others. Star of Pathe newsreels and David Putnam’s adventures for boys, David Goes to Greenland and David Goes to Baffin Land, which spread the name and fame of the venerable master and his schooner, Cap’n Bob and Morrissey, were as famous to the generation of the 1920s and 30s as Jacques Cousteau and Calypso were to the generation of the 1960s and 70s.’

    http://www.mass.gov/dcr/stewardship/curator/Ernestina_RFEI_2012.pdf

    Some of the Pathe news reels which enthralled our ancestors can be seen in this excellent series of films (some silent) These are not for the politically correct, or polar bears of a nervous disposition- Watch for the Intriguing end plate on one film which shall be referenced again shortly;
    ‘ In the next instalment we follow the hazardous trail of the Fury and Hecla into arctic waters where no ship has sailed for a century.’

    http://www.britishpathe.com/workspaces/MarkHarris/Captain-Bob-Bartlett-On-the-fringe-of-the-Pole-abo

    Bartlett’s serious science credentials can be seen in this short extract;
    ‘Similar (warming) changes have occurred throughout the Arctic in the natural vegetation, although as yet few examples have been recorded. Thus, in 1937, when approaching Disko Island in Bob Bartlett’s schooner Morrisey, I noticed that the flat tops of mountains west of Godhavn that formerly showed no green vegetation above the 2000-foot level were distinctly green from several miles away. During the summer of 1926, which I spent in Alaska, I noticed that on Seward Peninsula the vegetation was fully one month farther advanced that in 1879 when the Swedish botanist Kjellman collected there.

    http://www.thearcticcircle.ca/pdf/Arctic%20Circular%20Volume%202%201949.pdf

    This period of melting is generally accepted to have commenced in 1918 and lasted until at least 1939.”

    ——– ——

    Mods-sorry for the length of this post

    tonyb

  18. Faux Science Slayer says:
    May 30, 2012 at 10:50 am
    “Never trust real estate agents with horned helmets and dragon boats!”

    Now THIS is going too far. Let me be absolutely clear on the matter: Vikings DID NOT have horned helmets!!!!! The pictures you might have seen of horned helmets are from Bronze Age Denmark, and predate the Vikings by 1,000 years. Is not climate science all about accuracy? About getting time frames right? Huh? Huh?

    “Horned helmets on Vikings.” Those are fighting words.

  19. Mycroft
    I live close to Exeter. I was at the met office archives just today and Exeter cathedral library last week looking for material for a future article so my proximity to that city is very useful. Are you from this part of the world?
    Tonyb

  20. Some more background:

    I have plotted the raw GISS temperature data of all stations around Greenland’s inland ice (but need to make an update for the past years). See:

    http://www.ferdinand-engelbeen.be/klimaat/greenland_temp.html

    Greenland summer temperatures in the period 1930-1950 were higher than nowadays…

    And from: http://www.agu.org/meetings/fm05/fm05-sessions/fm05_C41A.html

    We first combined data from historical records, ground surveys, airborne laser altimetry, and field mapping of lateral moraines and trimlines. This record shows two periods of rapid thinning by about 70 meters, in the early 1950s and since 1997. Observed changes in glacier behavior during these two events are markedly different. The recent thinning, which involved several episodes of retreat followed by large thinning, resulted in a rapid retreat of the calving front toward grounding line. Thinning in the 1950s occurred during a period when the calving front was stationary with only minor annual fluctuations. Nevertheless, aerial photographs collected in the 1940s and 50s indicate that thinning extended far inland.

    Also the retreat and advancing of the Illulisat/Jacobshavn glacier was described here:

    http://rsl.geology.buffalo.edu/documents/csatho_j07j061.pdf

    “Intermittent thinning of Jakobshavn Isbræ, West Greenland, since the Little Ice Age”

  21. Greenland has been warmer not as warm. I’m too lazy this evening to dig up the peer reviewed research which I have posted on WUWT. Someone else may care to do so.

  22. This post reminds me of the satellites photos of the Pacific coral attols which showed that most had held their ground in the face of rising sea levels and some had even grown. Observations are the fly in the ointment.

    See Floating Island.

    http://wattsupwiththat.com/2010/01/27/floating-islands/

    http://wattsupwiththat.com/2010/06/02/tuvalu-and-many-other-south-pacific-islands-are-not-sinking-claims-they-are-due-to-global-warming-driven-sea-level-rise-are-opportunistic/

  23. “Considering available station data that are continuous and begin before 1900 (Table 3), the year 2006 is not outstanding. In this longer perspective, only 2003 at Tasiilaq is outstanding in recent decades. Over the past century, years in Greenland that register as abnormally warm, 1929, 1932, 1941, 1947, and 1960 are outstanding, having temperatures warmer than observed recently. Increases in GrIS melt and runoff during this past century warm period must have been significant and were probably even larger than that of the most recent last decade (1995-2006)”

    — Arctic Report Card 2007 http://www.arctic.noaa.gov/report07/essay_hanna.html

  24. This brings to mind the challenge of the temperatures that GCHN is trying to bring down. Iceland/Greenland of the 1940’s?

  25. Excellent news, as the melting Greenland glaciers have been one of AGW’s posterchild.
    Let us spread the word about it.

  26. Unfortunately, the paper itself is behind a paywall. I wanted to have a closer look at which glaciers retreated more in the 1930s period compared to the recent period.

    I believe, based on other papers that recent glacial retreat in Greenland is strongly related to aspect. South facing glaciers are retreating, while north facing ones aren’t. I wanted to see the location of the glaciers that retreated more in the 1930s.

    Atmospheric warming should affect different glaciers in the same area in a similar manner, and affect the same glacier in substantially the same way in different time periods. The differences found in this paper indicate that the 1930s warming was different to the recent warming.

  27. I recall that even Walt Meier acknowledged that greenland had been warmer at the beginning of the XX century.

  28. Unfortunately I cannot provide a reference for the following, as it is from memory.

    However, I recall a few years ago I was watching a BBC report on global warming, and the reporter had travelled to Greenland to film the disappearing glaciers. And one scene made be screem at the TV due to the extraordinary stupidity of the reporter.

    They showed us a bay that was ice free for the first time in living memory as the snow and ice no longer reached the water. And there in the bay were the remains of an old port – signs of buildings, and what looked like part of a jetty. And the reporter quite happily reported that nobody had known there had been a port here until global warming had exposed it!

  29. I consider that Greenland temperatures during the Viking seetlement period are very much underestimated. It would not surprise me if they were between 3 to 6 degC warmer than they are today. Agriculture was very primative back then. As we are discovering much of their farmland is still under glaciers. As those glaciers retreat, the Earth below is not easy to till and will not be so unless the land warms by several degrees. One must not forget that they did not have mechanical equipment (as is used today on farms) and tools were not as efficient as the cheap spade or fork that you buy today at your local garden shop. There were no fertilizers and genetically engineered seed was not as developed, no greenhouses etc and buildings were not iunsulated and could only be heated by open fire.

    Greenland was colonized for several hundred years. Climate/weather is notoriously variable from year to year. One can’t engage in subsistence farming and survive for hundreds of years if one was just on the threshold of sustainable farming. The predominant feature of the climate back then must have been years of plenty which would see them survive the few unexpectedly harsh years which undoubtedly must have been encountered from time to time. This points strongly to a much warmer climate than today.

    Of course, Greenland is not global. However, we know of no explanation that would explain why a small area of Greenland would be significantly warmer than it is today. What was the mechanism? Most likely the warm gulf stream was routed nearer Greenland and/or was warmer (the latter would indicate warmer global conditions) and/or jet streams were slightly different. That said, there is no reason to believe that conditions were just limited to Greenland and did not for example include the majority of Northern Europe. It is likely that the Vikings thrived because Northern Europe was warmer than it is today. Anyone who has lived even in Southern Scandinavia will know how harsh the climate is and it would not surprise me that it was more benign during the Viking period. .

  30. Torgeir Hansson says:
    May 30, 2012 at 1:34 pm
    Now THIS is going too far. Let me be absolutely clear on the matter: Vikings DID NOT have horned helmets!!!!! The pictures you might have seen of horned helmets are from Bronze Age Denmark, and predate the Vikings by 1,000 years. Is not climate science all about accuracy? About getting time frames right? Huh? Huh?
    “Horned helmets on Vikings.” Those are fighting words.

    Wow — who’d have suspected that the Vikings wore heirloom horned helmets?

    *running for the bunker*

  31. richard verney says:
    May 31, 2012 at 1:37 am
    I consider that Greenland temperatures during the Viking seetlement period are very much underestimated…One can’t engage in subsistence farming and survive for hundreds of years if one was just on the threshold of sustainable farming.

    They were doing more than subsisting — they were also growing (and harvesting) enough hay to provide fodder for the inhabitants of those 50-cow barns. The growing season today is too short to allow the hay they plant to reach maturity, so they have to harvest it half-grown.

  32. tonyb said..
    Mycroft
    I live close to Exeter. I was at the met office archives just today and Exeter cathedral library last week looking for material for a future article so my proximity to that city is very useful. Are you from this part of the world?
    Tonyb
    ————————————————————————————————————————-
    Yes born and bred.Look forward to your article/post in general as i believe we can learn alot from past climatic events/ occurances
    Are how are you received at the met offices with regards to past climate searches and the AGW issue?
    mycroft

  33. Of course, Greenland is not global. However, we know of no explanation that would explain why a small area of Greenland would be significantly warmer than it is today. What was the mechanism?

    The west Greenland settlements were all on the east side of fairly high mountains indicating that westerly foehn winds played a role in producing conditions warm enough for farming. A reduction in these winds may have played a role in the end of the settlements.

  34. mycroft

    I am an insignificant flea on the backside of the giant climate elephant. Anyway, the climate elephant very rarely visits its own archives.
    tonyb

  35. Another good resource for Greenland of the 1930s (and studded with pictures and maps):
    National Geographic, Sept. 1934, pp. 261-304, “Flying Around the North Atlantic” by Anne Morrow Lindbergh. She and her husband crossed the icecap twice, followed the coastline, from Disko Bay area to Clavering Island, visited Dr.Lauge Koch’s research area, and literally ”redrew” the map of some areas of Greenland. I expect the photos in the magazine are only the tip of the iceberg of those taken on this fllight.

  36. Tonyb said
    I am an insignificant flea on the backside of the giant climate elephant. Anyway, the climate elephant very rarely visits its own archives.
    ———————————————————————————————————————
    Yes but with enough fleas, even the biggest elephant can be bought to it knees. as regards to vististing their own archives…”lest we look into the mirror and see what we have become, and what was before”keep up the good work
    Mycroft

  37. What has been will be again,
    what has been done will be done again;
    there is nothing new under the sun.
    Is there anything of which one can say,
    “Look! This is something new”?
    It was here already, long ago;
    it was here before our time.
    No one remembers the former generations,
    and even those yet to come
    will not be remembered
    by those who follow them.

    Ecclesiastes 1.

  38. In the early 1920s and 1930s, temperatures were high, similar to that of the present, and this affected the glacial melt. At the time many glaciers underwent a melt similar or even higher than what we have seen in the last ten years.

    So the temperature was similar to today but the melt was HIGHER.

    Was quite hot in the US around that time.

  39. Donald

    Thanks for that gem. Conditions can change quickly in the arctic it seems as within 5 years of that report there was substantial melting. As phlogiston quotes above, there is nothing new under the sun
    Tonyb

  40. Latitude: There is soft “snout ice”, then there is hard ice. Greenland’s hard glacial ice is at around -70 to -80 deg F. Hard ice does not crack. Soft ice cracks. Hard ice takes a very long time to melt compared to soft ice. Density is different too.

  41. Jason Box, one of the authors of this paper on the 1930s glacial retreat, has stated that the glacial resurgence after the 30s was due to aerosols subsequent cooling.

    Box wants to blame humans for the current retreat and the preceding surge, but he did not do his homework. Ice core studies show that there were more aerosols pre-1940 than post 1940.

    http://www.sciencedaily.com/releases/2008/08/080819160103.htm

Comments are closed.