From the University of Innsbruck, another modeling study.
This news release is available in German.
The ongoing global glacier retreat causes rising sea-levels, changing seasonal water availability and increasing geo-hazards. While melting glaciers have become emblematic of anthropogenic climate change, glacier extent responds very slowly to climate changes. “Typically, it takes glaciers decades or centuries to adjust to climate changes,” says climate researcher Ben Marzeion from the Institute of Meteorology and Geophysics of the University of Innsbruck.
The global retreat of glaciers observed today started around the middle of the 19th century at the end of the Little Ice Age. Glaciers respond both to naturally caused climate change of past centuries, for example solar variability, and to anthropogenic changes. The real extent of human contribution to glacier mass loss has been unclear until now.
Anthropogenic Causes
By using computer simulations of the climate, Ben Marzeion’s team of researchers simulated glacier changes during the period of 1851 and 2010 in a model of glacier evolution. “The results of our models are consistent with observed glacier mass balances,” says Marzeion. All glaciers in the world outside Antarctica were included in the study. The recently established Randolph Glacier Inventory (RGI), a complete inventory of all glaciers worldwide, enabled the scientists to run their model. “The RGI provides data of nearly all glaciers on the Earth in machine-readable format,” explains Graham Cogley from Trent University in Canada, one of the coordinators of the RGI and co-author of the current study.
Caption: This image shows the Artesonraju Glacier in Cordillera Blanca, Peru.
Credit: Ben Marzeion
Since the climate researchers are able to include different factors contributing to climate change in their model, they can differentiate between natural and anthropogenic influences on glacier mass loss. “While we keep factors such as solar variability and volcanic eruptions unchanged, we are able to modify land use changes and greenhouse gas emissions in our models,” says Ben Marzeion, who sums up the study: “In our data we find unambiguous evidence of anthropogenic contribution to glacier mass loss.”
Significant Increase in Recent Decades
The scientists show that only about one quarter (25 +/-35 %) of the global glacier mass loss during the period of 1851 to 2010 is attributable to anthropogenic causes. However, during the last two decades between 1991 and 2010 the fraction increased to about two thirds (69+/-24%). “In the 19th and first half of 20th century we observed that glacier mass loss attributable to human activity is hardly noticeable but since then has steadily increased,” says Ben Marzeion. The authors of the study also looked at model results on regional scales. However, the current observation data is insufficient in general to derive any clear results for specific regions, even though anthropogenic influence is detectable in a few regions such as North America and the Alps. In these regions, glaciers changes are particularly well documented.
The study is supported, among others, by the Austrian Science Fund (FWF) and the research area Scientific Computing at the University of Innsbruck.
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dbstealey says:
August 15, 2014 at 6:11 pm
OK, who wants the first shot at Edward Richardson? ☺
=================================================
30 seconds of Googling and 20 minutes of excellent reading:
http://faculty.fgcu.edu/twimberley/EnviroPol/EnviroPhilo/Glacial.pdf
A nice excerpt:
http://i62.tinypic.com/6tcqyh.png
Birdbrain, print out the entire pdf, roll it up and shove it up your climate parasite ass.
philincalifornia says:
August 15, 2014 at 7:04 pm
An otherwise good study from “Climate Change” 1994 marred by the Team’s early attempt to move the end of the MWP back from c. 1450 to AD 1250, although it does recognize 1450-90 as the conventional date for onset of the LIA, based upon the whole range of paleo proxies, and suggests the interval 1250 to 1450 as still MWP, although in glacier data it could be seen as transitional.
philincalifornia says:
August 15, 2014 at 7:04 pm
..
” print out the entire pdf, roll it up and shove it up your climate parasite…..”
…
You can post a hundred, or a thousand data points to support your hypothesis that the MWP was warmer than today. However, I want you to address the data point at both the GNP and the Swiss Alps that falsify your hypothesis.
J.Swift says:
August 15, 2014 at 2:08 pm
Q: How many computer modelers does it take to change a light-bulb?
A: None; the model says it’s still working.
—————————————————-
LOL – like all great humour, exceptionally demostrates a truth.
Meanwhile
“While we keep factors such as solar variability and volcanic eruptions unchanged…”
Has someone told the sun and and volcanoes they are no longer allowed variability?
I understand the need to isolate functions in order to build an understanding of complex systems, but to confuse an isolated function with the system itself is…well..unforgivable.
Re: glaciers. Some are growing, and some are receding. That has more to do with local conditions than ‘global warming’. If global warming was the cause, they would all be receding.
Next, the MWP was a global phenomenon. If Mr. Richardson disputes that he is wrong, but it doesn’t matter. There is always the Roman Warm Period, the Holocene Optimum, and several others. They were all warmer than now, and they all occurred before human industrial activity was a factor.
Finally, it does seem that “Edward Richardson” is the erstwhile H Grouse [“chuck” before that]. They all argue the same way: always changing the subject, and throwing out extraneous facts, and cherry-picking. And confirmation bias permeates his comments; his conclusion is already arrived at. He then argues toward his preconceived conclusion. He absolutely will not learn anything. And when one of his sockpuppets would disappear, the next one would appear in its place.
That’s too much of a coincidence.
Maybe I’m mistaken, but until it’s proven one way or another, my default assumption is: H Grouse.
dbstealey says:
August 15, 2014 at 7:21 pm
.
“They were all warmer than now”
..
If they were warmer than now, how come we don’t find tree stumps at GNP that date 1000 BP or 2000 BP?
…
They are dating at 3000 years BP which proves the MWP and the Roman warm periods were NOT warmer than today.
For dbstealey: Can I take my first shot with my 12 gauge with slugs?
In case you haven’t heard, agricultural buildings, and tree stumps, and even people are being discovered as the permafrost melts. “Otzi” is an example.
They were frozen or buried in permafrost after they died, so it must have gotten much colder following the MWP. It is just warming up now, to the same temps as during the MWP, which must have been warmer. Those warm/cold cycles have been going on throughout the Holocene.
But we obviously still haven’t reached MWP temperatures because objects are still appearing, as the ground continues to thaw. That will probably keep on happening for quite a while longer — until modern temperatures reach those of the MWP.
Not my area of expertise, but aren’t proxy data very noisy? One point does not prove much then.
Edward Richardson says: […]
I know this guy is a troll, and I normally don’t feed trolls because when you do the nonsense never ceases. However…
Hey ER! Here’s a chance to prove your point, instead of cherry picking tree stumps. Wherever you are, sell everything and buy a herd of dairy cows, Guernseys, Holsteins, whatever you prefer, and some grass seed and whole oats. Buy passage on a freighter for yourself, your cows and your seeds to SE Greenland. Set up shop and keep us posted on the success of your dairy operation.
If Vikings from Iceland could do it for 300 years, I’m sure you’ll manage it as well. Seeing as how it was not as warm during the MWP as it is now.
stan stendera says:
August 15, 2014 at 7:30 pm
Only if they’re Green, environmentally friendly steel slugs and not lead.
Michael Wassil says:
August 15, 2014 at 7:39 pm
ER will be waiting a long time for the Norse dairy farms to thaw out of the permafrost. Unless he has nuclear powered giant blow driers.
Read the paper you f-kin dumbcluck. I’ll defer to someone else to pwn you on GNP. I can’t have all the fun.
http://i59.tinypic.com/2u8gymu.png
Edward Richardson says:
August 15, 2014 at 7:25 pm
…”They are dating at 3000 years BP which proves the MWP and the Roman warm periods were NOT warmer than today.”
——–
So what ?
You gonna just roll over and die at the first challenge ?
“All glaciers in the world outside Antarctica were included in the study.”
Most glaciers in Alaska don’t even have names. –AGF
philincalifornia says:
August 15, 2014 at 7:41 pm
He won’t. He didn’t even read the 1999 paper whence the dimwit got his crazy fixed idea about stumps (actually on the Canadian side of the international park):
http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=11&ved=0CFIQFjAK&url=http%3A%2F%2Fwww.geog.uvic.ca%2Fdept%2Fuvtrl%2F2000-02.pdf&ei=0sXuU4yyIoz-oQSbkoLABA&usg=AFQjCNEgMNG6sNQGeDgwzDGrWhwVpiVCDg&sig2=aHOgbnkeIbWaJCzN_RZe7w&bvm=bv.73231344,d.cGU
“This report describes the results of dendroglaciological investigations at
Saskatchewan Glacier, Banff National Park, Alberta. The Saskatchewan
Glacier flows ca. 10 km eastward from the Columbia Icefield through a
steep-walled valley between Mt. Castleguard and Mt. Adromenda. Since it
was first photographed in 1921, the glacier snout has receded several kms up
valley. Within the last two decades detrital wood (dating between 3180 and
2540 14C years BP) has periodically appeared at the ice front. It has been
assumed that these detrital branches and logs were derived from trees
overridden by a Neoglacial advance of the Saskatchewan Glacier.
In late-August 1999, a severe rainstorm resulted in ice proximal incision
along the northern periphery of the Saskatchewan Glacier. This resulted in
the erosion of over 6 m of till and outwash deposits, and the flushing of
large quantities of detrital boles, logs and stumps onto the outwash surface.
At the channel base, in situ stumps rooted within a well-preserved paleosol
were exposed. Radiocarbon dating established the stumps represented trees
killed between 2910 +/60 and 2830 ± 60 14C years BP. These radiocarbon
dates substantiate previous circumstantial evidence of a Neoglacial advance
at Saskatchewan Glacier and are illustrative of the approximate position of
the icefront at 3000 14C years BP.”
Notice nowhere does it say that other stumps of younger age have not been found in the valley. Note further that the c. three Ka carbon 14 years (uncalibrated for calendar years) dated stumps were exposed as a result of an unusual event, not a normal meltback retreat controlled by temperature and precipitation.
Note also that the amount of retreat 1921-38 v. 1977-94 is not included in the abstract.
sturgishooper says:
August 15, 2014 at 7:50 pm
—————————————–
Hopefully, whoever’s paying the saddo will grade him on this performance.
It’s models all the way…..oh wait, the glaciers on Mt. Shasta have been growing in mass since 1950. Well some data that didn’t fit the CAGW model must have been left out.
It seems as if they are running out of time for CAGW and don’t have time for studies of observational data. The models are now evidence, it must be the new science.
I would think that temperature and precipitation would be the two biggest factors in whether glaciers advance or retreat.
The global retreat of glaciers observed today started around the middle of the 19th century at the end of the Little Ice Age.
=================
so, here we have it. 1850 is the middle of the 19th century. The end of the Little Ice Age. Glaciers started to retreat as temperatures started to increase. And have kept increasing in fits and spurts for the next 150 years.
Since Climate Science has no idea what caused the Little Ice Age, they have no idea what caused it to end, and they can’t say with any certainty when the temperatures will stop increasing following the end on the LIA.
1850 is also the start of the modern temperature record. what a co-incidence, the LIA ends at the same time we start keeping thermometer records. Cause and effect?
To Sturgishooper,
The period 1250-1450AD was almost certainly climate transitional in North America. The Anisazi Indian Cliff Dwellers (of today’s preserved ruins at Meas Verde NP) rapidly abandoned their 7500-8000ft plateau cliff homes very abruptly around 1250AD. The best evidence indicates that a rapidly cooling climate, and thus too short a growing season for their plateau-top maize crops, resulted in their societal collapse and dispersement to lower warmer areas in New Mexico and Arizona. The NPS about 4 years ago changed their park documentation of that collapse to erase climate change as the reason, a gesture almost certainly politically motivated to erase the MWP.
JMO
Edward Richardson says:
August 15, 2014 at 4:42 pm
Find a tree stump exposed by the receding glaciers that dates back 1000 BP via radiocarbon dating, and I will accept your assertion that the MWP was warmer than now.
===============
milodonharlani says:
August 15, 2014 at 4:49 pm
http://www.livescience.com/39819-ancient-forest-thaws.html
A protective tomb of gravel likely encased the trees more than 1,000 years ago, when the glacier was advancing, Connor said, basing the date on radiocarbon ages of the newly revealed wood.
============
Ed, glad to see you have accepted that the MWP was warmer than today!
Joel O’Bryan says:
August 15, 2014 at 9:27 pm
The 14th & 15th centuries in North America were indeed challenging climatic times, & not just in the US SW. Europe too booked rapid shifts during that period. But average temperatures globally remained elevated compared to the 18th, 19th & 20th centuries, let alone the depths of the LIA in the 16th & 17th centuries.
I see rampant rewriting of climate history & temperature records by the feds. The corruption of science is spreading, but the disease might soon run its course. This year’s election will be crucial, but still the Administration, EPA, other agencies & their impish minions will wage a fierce delaying action against the new Congress.
ferdberple says:
August 15, 2014 at 9:35 pm
Good job on pasting the money quote. I should have done that. Maybe Ed/Grouse has an inkling now as to how glaciers work.