The whole can of larvae opened up by the flawed University of Colorado study turned press release keeps getting squirmier. The study, led by Yarrow Axford studies midge larvae in sediment cores from Baffin Island to reconstruct temperature for the past and claims that “The past few decades have been unique in the past 200,000 years in terms of the changes we see in the biology and chemistry recorded in the cores,” and “We see clear evidence for warming in one of the most remote places on Earth at a time when the Arctic should be cooling because of natural processes.”
As I’ve pointed out on WUWT several times, the study is terribly flawed, because they haven’t considered other possible factors, such as DDT and other pesticides being transported into the lake from nearby military outposts and settlements, plus the tendency for transport or organotoxins into glacial ice which ends up in meltwater lakes. Plus the nearby weather station shows no significant warming.
WUWT reader “Ecotretas” points out this July 2009 peer reviewed study Evidence for a warmer period during the 12th and 13th centuries AD from
chironomid assemblages in Southampton Island, Nunavut, Canada by Nicholas Rolland et al, which uses the same techniques, but just one island west of Baffin:
The Rolland et al study temperature reconstruction shows a significantly different result than that of Axford:
A similar sort of reconstruction was done in alpine lakes of the Alps with similar results.
Here’s the Abstract of the Rolland et al study:
This study presents the Late-Holocene evolution of a northern Southampton Island (Nunavut, Canada) lake, using fossil chironomids supported by sedimentological evidences (XRF, grain size and CNS). All proxies revealed a relatively stable environment during the last millennium with short-lived events driving changes in the entire lake ecosystem. The chironomid-based paleotemperatures revealed variations of significant amplitude coincident with changes in the sediment density and chemical composition of the core. Higher temperature intervals were generally correlated to lower sediment density with higher chironomid concentration and diversity. Higher temperatures were recorded from cal yr AD 1160 to AD 1360, which may correspond to the Medieval Warm Period. Between cal yr AD 1360 and AD 1700, lower temperatures were probably related to a Little Ice Age event. This study presents new information on the timing of known climatic events which will refine our knowledge of the paleoclimate and climatic models of the Foxe Basin region. It also provides a new framework for the evolution of such freshwater ecosystems under the “Anthropocene” and underlines the importance of including sedimentological proxies when interpreting chironomid remains as this combined approach provides an extended overview of the past hydrological and geochemical changes and their impacts on lake biota.
Conclusions and perspectives
The paleolimnological study of this northern Southampton Island lake provides information and extends the spatial understanding of Northern Hemisphere climatic events (Medieval Warm Period and Little Ice Age) in the Foxe Basin region. Both chironomid-based August air temperature inferences and sedimentological assemblages suggest that Southampton Island was affected by a regional warming between cal yr AD 1160–1360 and a regional cooling between cal yr AD 1360– 1700. These results compare well with both archaeological studies made on Southampton Island and paleoclimatic studies conducted on the southern part of Baffin Island. In the present study, the information extracted based on the biological indicators (chironomids) was supported by a large range of sedimentological analyses. Such results confirm the importance of including sedimentological proxies when interpreting chironomid analysis as they provided an extended overview of the past hydrological and geochemical status of the lake which has affected its biological community. The large number of lakes covering the arctic landscape provides a real opportunity to improve our knowledge of past natural climates in still poorly studied arctic regions and develop new frameworks for the evolution of such freshwater ecosystems under the now called “Anthropocene.”
The entire paper is available online here (PDF).
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Does that junk study really deserve so many rebuttals?
Greenland temperature reconstruction
http://chriscolose.files.wordpress.com/2008/11/easterbrook.jpg
Less Ice in Arctic 6-7000 years ago
http://www.sciencedaily.com/releases/2008/10/081020095850.htm
Northern Siberia warmer by 2.5-7 deg C 7-9000 years back
http://thedeadhand.com/Resources/ReferenceLibrary/tabid/164/articleType/ArticleView/articleId/184/Holocene-Treeline-History-and-Climate-Change-Across-Northern-Eurasia.aspx
Any junk study that gets MSM attention needs rebuttal. I haven’t seen any press treatment of the studies that show no AGW, they may be out there, but not evident.
At what point does this series of stories qualify as “kicking a dead midge”?
🙂
Impressive accuracy, showing all climatic epochs. To download the PDF inmediately.
The use of biological sedimentation proxies, while confirming the existence of a MWP in the Western hemisphere, seem to indicate a substantially shorter warm period – 1160 is a very late date for the onset of this phase, compared with MWP dates in Europe, although the end of the warming appears to coincide with the European dates. What would this suggest for natural climate forcing mechanisms?
REPLY: Remember this is AUGUST temperatures, not the entire year. Thus comparing to a yearly average seen elsewhere is likely to have differences. – A
This is a bit lame, and totally O/T, but I suggested that RealClimate’s lead story: Climate Cover-Up: A (Brief) Review’s first sentence “We often allude to the industry-funded attacks against climate change science, and the dubious cast of characters involved, here at RealClimate.” would be more factual if the commas were left out. It got through the comment nazis:
116 I think the first sentence of this story makes for much more factual reading if the commas are left out.
Comment by Tattymane — 21 October 2009 @ur momisugly 4:22 PM
I wonder how long it’ll be before they twig? . . .
Are there midges in the Yamal region? It would be interesting to see how those tree rings correlate to midges
Yes, real science is Baffining (sic) to these climate loons most of the time.
Interesting that we have only 22 cm of sediment in a thousand years.
A strong MWP only brings the use of the term “unprecedented” into question.
The crucial piece for re-establishing serious consideration of “How much of the warming is quantifiably anthropogenic anyway?” would involve showing that the Little Ice Age was strong, geographically pervasive, andor lengthy.
vigilantfish wrote:
“The use of biological sedimentation proxies, while confirming the existence of a MWP in the Western hemisphere, seem to indicate a substantially shorter warm period – 1160 is a very late date for the onset of this phase, compared with MWP dates in Europe, although the end of the warming appears to coincide with the European dates. What would this suggest for natural climate forcing mechanisms?”
In the Canadian Arctic the post-glacial warming moved from west to east. It is entirerly possible that a similar pattern held for the MWP. Remember, there are large ice sheets just to the east on Greenland.
Correlate tree rings to midges? Brilliant.
I know the answer is in that bit of scientific work.
Below is a link to the Axford study abstract. The paper itself is behind a paywall.
The interesting part,
Paleoecological and geochemical data indicate that the past three interglacial periods were characterized by similar trajectories in temperature, lake biology, and lakewater pH, all of which tracked orbitally-driven solar insolation. In recent decades, however, the study site has deviated from this recurring natural pattern and has entered an environmental regime that is unique within the past 200 millennia.
The tracking of orbitally-driven solar insolation by climate indicators is the significant finding of the study. This finding predictably was omitted from the press release. Can’t have the masses thinking the orbit of the sun drives the Earth’s climate.
The last sentence contains no specifics of what deviations were found, which is unacceptable in a scientific abstract. And without access to the paper I can’t comment further. Except to say the last sentence sounds like the usual ritual affirmation of AGW tacked on to any paper that doesn’t find clear evidence of AGW.
http://www.pnas.org/content/early/2009/10/16/0907094106.abstract
OT — Meanwhile….in post-Mideval Warm Period and post Little Ice Age Bavaria…
Germany records its coldest ALL TIME October temperature EVER.
A balmy Negative 12 Fahrenheit.
http://www.thelocal.de/society/20091020-22693.html
Chris
Norfolk, VA, USA
If there was significant warming during the ‘MWP’ it would seem fair to expect Atmospheric methane levels to rise, due to warming wetlands. Clearly there was no rise.
http://www.ghgonline.org/humaninfluence.htm
4 billion,
Your link has no information on the MWP and methane levels.
But it does contain some bad science writing, such as,
The problem (of GHG warming) is exacerbated by our poor level of understanding of exactly how some factors, like land-use albedo (the reflectance of the land), operate and interact.
I can reassure that our understanding of these factors has exactly zero effect on GHG warming.
In addition, it is pure speculation that any or all these factors exacerbate GHG warming. Some or all may mitigate it.
See this
http://www.thelocal.de/society/20091020-22693.html
Philip_B (20:17:34) :
4 billion,
Your link has no information on the MWP and methane levels.
–
The link contains a graph of the last 1000 years of atmospheric methane levels.
Warming wetlands release more methane, they are source for 20% of the current high levels of atmospheric methane.
http://icp.giss.nasa.gov/education/methane/intro/cycle.html
Seeing that this a quick response to warming, seems like there should be a similar methane rise during the MWP.
James
4 billion,
Methane is OT for this thread, but I will answer your question.
Firstly, you are assuming methane release from wetlands rises and falls with temperature. This is probably (possibly?) not the case and at or around current temperatures methane release is at a maximum. See link below
Secondly, methane levels derived from ice cores are problematic because it is difficult to explain the variation from biological sources alone, and release of methane hydrates for example is invoked as an explanation. See same link.
Thirdly, if you rescaled the methane graph from your link, you would see there is a rise during the MWP.
http://www.sciencedaily.com/releases/2008/02/080217093816.htm
BTW, making statements like ‘Warming wetlands release more methane’ with the implication it comes from the link following when in fact the link says nothing like this, is not kosher.
For the record your link says.
However, wetland response to climate change predicted for the next century is highly uncertain.
This type of study, in this particular area, may give very misleading results for following reason:
Proliferation of midges in the area may be a function of total marshy area (favoured by mosquitoe type insects). This is an area of instability in that respect due to postglacial uplift (after-effect of Laurentide ice sheet), hence land uplift above water line would considerably affect ecosystem processes in shallow water areas over an extended period of time.
http://www.erudit.org/revue/gpq/2005/v59/n2-3/014753ar.html?vue=figtab&origine=integral&imID=im6&formatimg=imPlGr
As I understand it the Thule Inuit replaced the Dorset inuit around a 1000 years ago in the Canadian Arctic during a warm period. Spreading from the West they got as far as Greenland and made contact (freindly? -unfreindly?) with the Vikings. At the same time I recall a programme about the Greenland Viking community and how their fortunes could be tracked using a variety of archeological and forensic techniques including the type of flies found.
All things being equal cross referencing a variety of evidence types can create a useful picture, but the quality of that picture will only ever be as good as the person looking at it.
OT. Nov 1976 National Geographic on the climate. The article warned of two scenarios if the world either warmed or cooled:
[1] “Higher temperatures might expand arable land – but only if accompanied by increased rainfall. Warmth however, might bring drier conditions”.
[2] “Lower temperatures could produce a climate generally wetter and less stable, one marked by storms, floods, and freezes”.
In the same article are pictures of the Hintereisferner Glacier (Austria) taken over a period of time ending in 1956 where the glacier has receded a mile from it’s furthest advance and is further back than it is today.
Hope nobody finds a very special and crippled midge to construct a hockey stick out of a single one midge. 🙂
Did anyone actually look at the study? Here’s its conclusion:
“The paleolimnological study of this northern Southampton Island
lake provides information and extends the SPATIAL UNDERSTANDING of
Northern Hemisphere climatic events (Medieval Warm Period and
Little Ice Age) in the Foxe Basin region. Both chironomid-based August
air temperature inferences and sedimentological assemblages suggest
that Southampton Island was affected by a REGIONAL WARMING between
cal yr AD 1160–1360 and a regional cooling between cal yr AD 1360–
1700. These results compare well with both archaeological studies
made on Southampton Island and paleoclimatic studies conducted on
the southern part of Baffin Island” (Capitals mine).
We’re talking about a regional warm period, not a global one. The results “compare well” with past studies, so it’s not offering new conclusions.
Stop making mountains out of molehills.
Philip_B (01:15:32) :
Methane has been shown to rise with rising wetland temperature.
http://www.springerlink.com/content/k752801237738874/
the graph doesn’t need to be rescaled, there is no comparable methane release 800 years ago to the natural release of today.
All I am proposing is that one would expect wetlands to release similar amounts of methane during the ‘mwp’ to similar amounts as todays wetlands do, if the temperature was as warm as now.
Your link talks about Methane release during Glacial periods thus not really applicable to the time period.
I’m curious to know why they think the Arctic “should” be doing anything. Do they have a crystal ball telling them what “should” be going on anywhere in the world at any given time?