Beam me to Planet Gore !
Posted on 09/24/2009 12:54:07 PM PDT by ConservativeMind
A new study that reports precise ages for glacial moraines in southern Peru links climate swings in the tropics to those of Europe and North America during the Little Ice Age approximately 150 to 350 years ago. The study, published this week in the journal Science, "brings us one step closer to understanding global-scale patterns of glacier activity and climate during the Little Ice Age," says lead author Joe Licciardi, associate professor of Earth sciences at the University of New Hampshire. "The more we know about our recent climate past, the better we can understand our modern and future climate."
The study, "Holocene glacier fluctuations in the Peruvian Andes indicate northern climate linkages," was borne of a convergence of a methodological breakthrough in geochronological techniques and Licciardi's chance encounter with well-preserved glacial moraines in Peru.
On vacation in 2003, Licciardi was hiking near the well-known Inca Trail when he noticed massive, well-preserved glacial moraines - ridges of dirt and rocks left behind when glaciers recede -- along the way, about 25 kilometers from the ruins of Machu Picchu. "They very clearly mark the outlines of formerly expanded valley glaciers at various distinct times in the recent past," he says. But Licciardi, who had no geologic tools with him at the time, did not take any samples.
Two years later, coauthor David Lund, assistant professor of geology at the University of Michigan and a friend of Licciardi's from graduate school, was in the same region and offered to chisel off some samples of the salt-and-pepper colored granitic rock. "Dave also recognized the potential of this site and shared my enthusiasm for initiating a study," says Licciardi. "That was the catalyst for turning our ideas into an actual project." Licciardi returned in 2006 to the slopes of Nevado Salcantay, a 20,000-foot-plus peak that is the highest in the Cordillera Vilcabamba range. Over the next two years, he and his graduate student Jean Taggart, also a coauthor, collected more rock samples from the moraines.
The researchers analyzed the samples using a surface exposure dating technique -- measuring the tiny amounts of the chemical isotope beryllium-10 that is formed as cosmic rays bombard exposed surfaces -- to place very precise dates on these relatively young glacial fluctuations. Licciardi and Taggart, who received a master's degree from UNH last month, worked with coauthor Joerg Schaefer, a geochemist at Columbia University's Lamont-Doherty Earth Observatory, to produce some of the youngest ages ever obtained from the beryllium isotope dating method.
"The ability to measure such young and precise ages with this method provides us with an exciting new way to establish the timing of recent glacier fluctuations in places far afield from where we have historical records," says Licciardi. Because the Little Ice Age - from about 1300 AD to 1860 AD -- coincides with historical accounts and climate observations in Europe and North America, the event is well documented in the Northern Hemisphere. In remote and sparsely inhabited areas like the Peruvian Andes, however, chronologies of Little Ice Age glacial events are very scarce.
A key finding of the study is that while glaciers in southern Peru moved at similar times as glaciers in Europe, the Peruvian record differs from the timing of glacier fluctuations in New Zealand's Southern Alps during the last millennium, as reported in another recent study in Science led by Schaefer.
"This finding helps identify interhemispheric linkages between glacial signals around the world. It increases our understanding of what climate was like during the Little Ice Age, which will in turn help us understand climate drivers," says Taggart.
"If the current dramatic warming projections are correct, we have to face the possibility that the glaciers may soon disappear," adds Schaefer.
Licciardi and his colleagues will continue working in Peru toward a more complete understanding of glacial expansion during the Little Ice Age - and their subsequent retreat. "Our new results point to likely climate processes that can explain why these glaciers expanded and retreated when they did, but there are still many open questions," he says. "For example, what's the relative importance of temperature change versus precipitation change on the health of these glaciers?" The research team plans to explore this question using coupled climate-glacier models that evaluate the sensitivity of glaciers in southern Peru to the two main factors that drive glacier expansion - cold temperatures and abundant snowfall.
Remember, the Little Ice Age corresponded precisely with the lack of sunspots. GW proponents have stated there was no correlation between the sunspots and the Little Ice Age because they believed the Southern Hemisphere had no corresponding dip in temperatures.
They did.
Interestingly, the study's authors spin this to say that "If the current dramatic warming projections are correct, we have to face the possibility that the glaciers may soon disappear."
They've got to keep up the Global Warming end of things, right?
Ping of interest.
Ping of interest.
/mark
I'm convinced that funding for their work is contingent on their mentioning global warming in any of their reports.
I think you're right.
In a peer-reviewed journal, you must take into account the biases of the review panel. If you go too far outside the reviewers frame of reference your work may be considered “too controversial” or “not well founded”. If your paper directly contradicts the work of one of the reviewers, it will be difficult for that reviewer to be objective (and some may spike it to protect their turf).
It's funding to a degree, but I think the personal dynamics of the review process play a large role too.
I have been on review panels before and I've seen otherwise good papers rejected because of one small thing that got a few reviewers upset.
So you see cases where a paper seems to refute AGW theory, but will have a sentence about the robustness of AGW.
What always baffles me is why saving glaciers is an important thing to worry about. Glaciers are just larger versions of the snow piles that melt at the end of a long winter. They don’t have a life to be saved. They are just collections of ice.
If all the glaciers melted and ceased to exist, how would we be worse off? Seems to me the net benefit would be more liquid water for the planet. Maybe coastal life would be affected, but from the estimates I’ve heard, water levels wouldn’t move much more than tidal changes.
So what’s the big deal about disappearing glaciers? Maybe we’ll find some more interesting bodies buried that will teach us something about our past.
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The study just published was not the study done by Shaefer; for Shaefer to now insert his opinion on the new work without being a contributor carries as much weight as your own.
The importance here, if any, is that this work gives a new geological opportunity to replace the terribly interpreted results from other, more widely publicized proxies that all seem to lead to support the warming theory that fits the current models.
The reporter is giving us his version of the released press report, if you want to read the whole thing, you must subscribe to Science.
Shaefer however gets credit for the berrylium dating and was puzzled by his earlier work reported on in April of this year; among some quotes from that work, I pulled these:
“The new chemical and analytical protocols developed in Schaefer’s cosmogenic dating lab is expected to allow scientists to accurately date glacier fluctuations throughout the Holocene, rounding out the climate picture on the continents.
“With this measure we can go to almost any mountain range on earth and date the moraines in front of the glaciers and produce a similar chronology,” said coauthor George Denton, a glaciologist who is a senior professor at the University of Maine and an adjunct scientist at Lamont-Doherty.
Overall, glaciers around the world have been declining since about 1860, with the exception of a brief advance in Switzerland in the 1980s, New Zealand in the late 1970s through today, and a few other places. Changes in wind and sea surface temperatures are thought to be causing these regional fluctuations. Currently in a wet phase, New Zealand is expected to swing back to a warmer, drier phase in the next few years, causing the glaciers to retreat once again.”
The result here of course is to bury the Little Ice Age so important to supporting the Mann ‘Hockey Stick” and New Zealand’s glaciers seem tailor made while this new work clearly shows that the new dating puts a good portion of the event in the southern hemisphere, after all.
Yup. I cancelled ny subscription to National Geographic because they're doing the same...I told them so too...
If all of the ice in the glaciers and on Greenland and Antarctica melted, sea level would rice by about 200 feet. This is not a matter of dispute. The dispute is whether or not the ice is melting.
I can't find the post now, but I saw one on FR within the past couple of days in which (as best I can recall) the poster said that a grad student in some climate related field told him (her?) twenty years ago that funding depended on putting things "in a global warming framework".
Sort of like the pagan Romans demanding a bit of incense tossed to the emperor (you didn't have to mean it, just do it!).
In any case, that's a big "if"! And what does he mean by "soon"? Tuesday? 10,000 years from now (which is soon in geologic terms)?
If all the ice in continental glaciers melted, which is what I meant, that would only be 0.29% of the total ice. Most of the planet’s ice is in Antartica and Greenland ice packs, and the last I heard these were steady.
There will need to be so many rewrites and reversals when this GW scam is finally put to rest. Unfortunately, the monies lost or spent around this issue can never be recovered, and, unfortunately, those monies have gone to precisely the wrong people from the start. They will be left with banks full of money to instigate the next socialist scam for power from a future ‘non-issue.’
80+% of the worlds' glaciers are in Alaska. I just read that last week.
There’s a big conference set for December, and a big push to get legislation installed by then. I suspect there will be a cold winter.
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