An event similar to one 15,000 years ago is blamed on global warming today

From the University of New South Wales. The logic here seems a bit muddled. If this event where migration of westerly winds towards the south pole happened 15,000 years ago, what makes them think that it happening again now is due to global warming?

Global warming endangers South American water supply

Tuesday, July 29: Chile and Argentina may face critical water storage issues due to rain-bearing westerly winds over South America’s Patagonian Ice-Field to moving south as a result of global warming.

A reconstruction of past changes in the North and Central Patagonian Ice-field, which plays a vital role in the hydrology of the region, has revealed the ice field had suddenly contracted around 15,000 years ago after a southerly migration of westerly winds.

This migration of westerly winds towards the south pole has been observed again in modern times and is expected to continue under a warming climate, likely leading to further ice declines in this area affecting seasonal water storage.

“We found that precipitation brought to this region by Southern Hemisphere westerlies played an important role in the glaciation of the North Patagonian Ice-Fields,” said Dr Chris Fogwill from the Climate Change Research Centre at the University of New South Wales.

“Our research has shown this ice-field significantly reduced in size when those winds moved southwards.”

The North Patagonian Ice-field is vital to maintain seasonal water storage capacity for Argentina and Chile.

“Worryingly, this study suggests the region may well be on a trajectory of irreversible change, which will have profound impacts on agriculture and the increasing dependency on hydroelectric power in Chile and Argentina,” Dr Fogwill said.

The team revealed the importance of the winds on the ice-sheets and consequent water supply by using rare isotopes to uncover changes in the ice-sheet thickness since the last major glaciation. This revealed the decline in the ice-sheet between 15,000 to 19,000 years ago.

Using a separate collection of ocean cores they were then able to determine that this decline coincided with the movement southwards of the westerlies.

The researchers found that a lack of precipitation caused by this movement, coupled with additional warming caused by rapid ice loss saw a sharp decline in glaciers with no seasonal recovery.

Interestingly, the southern part of the ice-field did not appear to be impacted by the movement of these winds. Instead it appeared that ocean currents and temperatures played a more important role in maintaining the ice in this section.

“The ice-field in the Northern and Central region of the Patagonian ice-field are highly sensitive to precipitation and need this to remain healthy,” said Dr Fogwill.

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Paper: Rapid thinning of the late Pleistocene Patagonian Ice Sheet followed migration of the Southern Westerlies (DOI: 10.1038/srep02118)

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GlynnMhor
July 30, 2013 9:09 am

This seems not atypical of the alarmist crowd.

elftone
July 30, 2013 9:11 am

There’s that word again – “irreversible”. It should never be used with respect to climate.
The rest of the article reproduced above *is* muddled, uses emotive language, and offers no explanation as to why this happened before (at least they didn’t say “unprecedented”).

TomRude
July 30, 2013 9:19 am

Another evidence of ignorance… These guys should read Leroux and understand what’s really happening, and it is NOT warming. The repeated cold waves for many years now affecting South America debunk their preposterous, attention grabing garbage.

duncanbinks@gmail.com
July 30, 2013 9:20 am

Anthony Watts posted: “From the University of New South Wales. The logic here seems a bit muddled. If this event where migration of westerly winds towards the south pole happened 15,000 years ago, what makes them think that it happening again now is due to global warming?”

Tom in Florida
July 30, 2013 9:20 am

“The North Patagonian Ice-field is vital to maintain seasonal water storage capacity for Argentina and Chile.”
Surely this was the intended reason for the formation of this ice-field.

dp
July 30, 2013 9:23 am

I can’t help but think the only possible solution for this leftist horror claptrap is to destroy world economies and rush pell-mell back to the stone age. Don’t get in my way, people!
/snarc

Jorge
July 30, 2013 9:35 am

Did you read the new report that 1700 cities will be underwater by end of century, 80 by end of decade? Good grief, these idiots are really becoming unhinged now, aren’t they?

Ian W
July 30, 2013 9:39 am

Jorge says:
July 30, 2013 at 9:35 am
Did you read the new report that 1700 cities will be underwater by end of century, 80 by end of decade? Good grief, these idiots are really becoming unhinged now, aren’t they?

They feel that they have to get all the taxes and governance in place before even more people question their scares. Time is short hence the ratcheting up of the panic stories.

Margaret Hardman
July 30, 2013 9:40 am

Anthony, I don’t see the logic is faulty. An event caused by changing wind patterns 15,000 years ago could be repeated in the near future as wind patterns change as climate changes. No real logic failure there.

Julian in Wales
July 30, 2013 9:41 am

A new scare story a day; one imagines they are so short of new ideas that they have to sit in a room and think up something silly.

July 30, 2013 9:46 am

I remember back in the ’80s when South America was positively doomed because of the “ozone hole” that we were supposedly causing. Turned out that was just natural variation, too.

numerobis
July 30, 2013 9:47 am

It took over 1,000 years for Western Europe to recover from the end of the roman warm period and reconstitute a literate society with centralized governance and important trade links. Reversible over the course of history, but irreversible over the course of memory.
When warmists talk about irreversible effects, it really means irreversible over a time span shorter than several centuries.

taxed
July 30, 2013 9:48 am

So they seem to be saying that something that last happen in the middle of the last ice age.
ls now further proof of global warming.
Yes that makes total sense.

tadchem
July 30, 2013 9:51 am

To answer the question “what makes them think that it happening again now is due to global warming?” I invoke the old proverb ‘When the only tool you have is a hammer, everything begins to look like a nail.’

Bloke down the pub
July 30, 2013 9:51 am

This migration of westerly winds towards the south pole has been observed again in modern times and is expected to continue under a warming climate,”
No worries then, no more warming – no poleward migration.

July 30, 2013 9:58 am

I don’t believe I’ve ever seen so many non sequiturs in a paper. It’s the Plan 9 from Outer Space of science papers …
Pointman

July 30, 2013 9:59 am

To be fair, they don’t claim, in the piece above anyway, that the warming they are talking about is in any way man-made.

July 30, 2013 10:02 am

Why would you take a time period that was squarely in the last ice age with temps well below today’s as a comparison of what we see today? During the last ice age, indeed, the air was cooler and drier with or without westerlies, whether migrating or not.
When this epidemic is over with, we have a big clean up to do. We will have to asterisk the PhD’s of the last two decades, quarantine them for remedial courses and examinations. We will have to retrain the 90% redundancy of climate scientists into other fields for which they would be obliged to take courses and proficiency examinations, notably in statistics. Many would likely prove unsuitable for acceptance into the new academic sphere. We will have to mark journals of this period with some form of color coding in libraries for review for retraction of 75%+ of the articles as being unscientific. This will all be a costly but worthwhile exercise because it will help to ensure that this “Laputa” bunch is disenfranchised forever.
“Gulliver sets sail again and, after an attack by pirates, ends up in Laputa, where a floating island inhabited by theoreticians and academics oppresses the land below, called Balnibarbi. The scientific research undertaken in Laputa and in Balnibarbi seems totally inane and impractical, and its residents too appear wholly out of touch with reality.”
http://www.sparknotes.com/lit/gulliver/summary.html

July 30, 2013 10:10 am

Likely an interesting study, under the bright pink tutu it is necessary to prance about in, to gain grant money.

wws
July 30, 2013 10:17 am

It’s like the Heartbreak of Psoriasis – EVERYTHING is caused by Global Warming!!!
re; Pointman’s notice of the Non-Sequitur’s in this paper – remember, this is post-modern science. It’s not illogical if you RILLY, RILLY, RILLY BELIEVE! that it is the truth. Whatever “truth” means anymore.

John Tillman
July 30, 2013 10:19 am

Gary Pearse says:
July 30, 2013 at 10:02 am
Apropos allusion for Los Putos Mann, et al.
Also for the allusion to Swift’s Laputa, the B-52 target in the movie “Dr. Strangelove”.

AnonyMoose
July 30, 2013 10:20 am

Irreversible… just as it never reversed since 15,000 years ago, so these ice fields never existed.

Mike Tremblay
July 30, 2013 10:31 am

Isn’t that about the time that people arrived in the Western Hemisphere – so it is our fault after all.

taxed
July 30, 2013 10:36 am

Caleb
l think l may know the reason behind this.
Since l have been taking a interest in the global jet stream since 2011. l have noticed that the southern jet stream quite often takes a dive to the south just before it reaches South America. With the jet stream behaving this way would explain why the westerly winds have moved to the south. This is also linked to the warming of Antarctica to the south of South America. As this jet pattern sends warm air down to this part of Antarctica. The fact that this part of Antarctica has been warming. Suggests that this southward movement of the jet in this area has been on the increase in recent years..

Jimbo
July 30, 2013 10:37 am

When I see papers like this I wonder what else could cause drought in Patagonia? I go off to look. But first here are many examples of low co2 induced mega droughts around the world during our benign Holocene.

Extreme and persistent drought in California and Patagonia during mediaeval time
STUDIES from sites around the world1–5 have provided evidence for anomalous climate conditions persisting for several hundred years before about AD 1300. Early workers emphasized the temperature increase that marked this period in the British Isles, coining the terms ‘Mediaeval Warm Epoch’ and ‘Little Climatic Optimum’, but many sites seem to have experienced equally important hydrological changes. Here I present a study of relict tree stumps rooted in present-day lakes, marshes and streams, which suggests that California’s Sierra Nevada experienced extremely severe drought conditions for more than two centuries before ad ~ 1112 and for more than 140 years before ad ~ 1350. During these periods, runoff from the Sierra was significantly lower than during any of the persistent droughts that have occurred in the region over the past 140 years. I also present similar evidence from Patagonia of drought conditions coinciding with at least the first of these dry periods in California. I suggest that the droughts may have been caused by reorientation of the mid-latitude storm tracks, owing to a general contraction of the circumpolar vortices and/or a change in the position of the vortex waves. If this reorientation was caused by mediaeval warming, future natural or anthropogenically induced warming may cause a recurrence of the extreme drought conditions.

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