Archive for the ‘Geography’ Category
Misleading Pictures, Wrong Caption…
And so once more Global Warming has meant the publication of misleading pictures, with a wrong caption…why oh why does the mere mention of AGW force so many otherwise thoughtful and wise people to switch their brains off?
Here a “Letter to the Editors” just sent to the New York Review Of Books:
Dear Editors
Clarifications and at least one correction are required about the pictures of the Upsala Glacier in Patagonia, Argentina, “from Al Gore’s An Inconvenient Truth (2006)”, on the first page of Bill McKibben’s “Warning on Warming” (NYRB, March 15, 2007).
At the top, the 1928 photograph of a vast flat glacier; at the bottom, the 2004 ice-free landscape as captured from a similar vantage point as the one 76 years earlier (at least two peaks are clearly distinguishable).
I was surprised indeed to see the New York Review of Books reproduce without much commentary and with a wrong caption a couple of photographs that may turn out to be exceedingly misleading.
(A) CORRECTION
First of all: the caption is wrong. Contrarily to the published text, it is _not true_ that by 2004, “most of the glacier had melted“.
Upsala Glacier still occupies well in excess of 850 sq km (330+ sq mi), an area vastly larger than the one covered by the photographs.
You can see pictures of Upsala taken from the Space Shuttle in January 2004 at the NASA website.
A discussion of the situation 2001-2004 is available on the same site.
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(B) CLARIFICATIONS
If one could rely on photographs alone, those of Upsala could be the definitive, final, closing, incontrovertible evidence that something has warmed up during the XX century, at least at the location of the Upsala Glacier.
Pictures, however, are not everything, as any modern consumer must have learnt one way or another by now.
Do some little research about Upsala, in fact, and more than one doubt arises about the glacier’s changes having not been mostly caused by warming, global or local or otherwise.
They may be the result instead of the behavior of a large glacier when subjected to particular mechanical stresses.
See for example “Historic Fluctuations of Outlet Glaciers from the Patagonian Ice Fields” at the USGS web site.
That web site reports a picture from “Thinning and retreating of Glaciar Upsala, and an estimate of annual ablation changes in southern Patagonia“, by R. Naruse, P. Skvarca and Y. Takeuchi (Annals of Glaciology, Vol. 24, 1997).
In that paper, it is suggested that “considerable retreat due to calving may have resulted in reduction of longitudinal compressive stress exerted from bedrock rises and islands near the glacier front, causing a considerable decrease in the emergence flow.”
R. Naruse repeated similar considerations at the 2nd International Symposium on Arctic and Antarctic Issues, at Punta Arenas, Chile, in November 1998 (“Dynamic features of glaciers in Patagonia“).
More recently, in “Recent behavior of Glaciar Upsala, a fast-flowing calving glacier in Lago Argentino, southern Patagonia” (Annals of Glaciology, 36, 2003), P. Skvarca, B. Raup and H. De Angelis proposed again that “drastic glacier retreat in the last two decades” may be explained “partly due to the release of back stress when the glacier retreated beyond the islands in Brazo Upsala […] which acted as pinning points.”
You can also read an earlier paper by Mr Skvarca: “Significant Ice Retreat in the Region Patagonia – Antarctic Peninsula Observed by ERS SAR” (ESA ERS 1997 Workshop, 1997) by H. Rott, W. Rack, M. Stuefer and P. Skvarca:
“It cannot yet be assessed if the ice retreat in Patagonia […] indicates just regional changes of the atmospheric circulation patterns or can be assigned to global climatic change.”
Last but not least, Upsala is not the only glacier in Patagonia.
Surely if the dramatic retreat of Upsala were related to global warming, all the other glaciers would be retreating too? And yet that is clearly not the case.
Read “Recent Fluctuations and Damming of Glacier Perito Moreno, Patagonia” by H. Rott, M. Stuefer, T. Nagler and C. Riedl (ESA Envisat and ERS 2004 Symposium):
“The satellite data, in synergy with field measurements, confirm the stability of the [Perito Moreno] glacier, showing only minor front fluctuations and indicating an approximately balanced mass budget since many years.”
Furthermore, they report the Pio XI glacier as having experienced a “net advance of about 10 km […] from 1945 to 1995“.
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Some revealing considerations should be made about Perito Moreno glacier indeed, the advancing glacier whose pictures have been used by Frank Capra in 1958 and by Al Gore in 2006 to demonstrate the retreat of glaciers due to global warming: but those will have to wait for a future article or letter.
For the time being, I am confident the above makes the main points clear:
(1) Most of the Upsala glacier has not melted.
(2) The Upsala glacier 1928-2004 pictures can only be seriously understood with an in-depth commentary of what is being shown, including “what lies beneath”.
And there are all the indications that the local characteristics of the terrain, rather than “Global Warming”, have had a major role in what has been happening.
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Given the reputation of the New York Review of Books then, I will be expecting a prompt publication of this letter and of all the necessary explanations.
Keep up the good work
Regards
Maurizio Morabito
UPDATE: The NYRB went only as far as admitting the caption was wrong (read it here)…
Borders that matter
From "A Muso Duro" (Marco Belpoliti, La Stampa, 20 June 2006 (in italian)):
In truth the geographic divide in the Italian Peninsula is not between the North and the South, but between East and West. The Italian "Boot" is more tilted than it appears in classrooms' maps, and it is possible to travel from North to South on the Adriatic side without crossing any mountain: from Venice to Bari there is no separation clear border, apart from the Po, which it is not a true dividing line between North and South (are Emilia and Romagna regions of the Italian South?). The geographers have explained to us for a long time that the true geographic difference in Italy is that between the Adriatic and the Tyrrhenian sides, even if it is obvious that the cultures follow the "geographic quotas", and the differences between the villages placed East or West of the Appennini are never clear-cut
This is not just a phenomenon of the Appennini
Think of the Alps, where cultures have diffused among the mountains: therefore distributing themselves across the watersheds, instead of considering those like border lines
Mountain chains all over the planet (look at the Caucasus, the Himalayas, the Rocky Mountains), looking to the modern eye like "natural borders", have been demonstrated time and again as lines of union, and not of separation
A "geographic border" with more important social consequences exists, and it is the border between those within easy approach of great ways of communication, and those far away or on the periphery: the wealth of the Po Valley instead of the history of poverty on the surrounding mountains; the powerful economy of the close-to-Europe Italian North, instead of the perennial crisis of the faraway Italian South; and looking at other countries, the opulence of Paris and London instead of the marginalization of their peripheries
Maurizio - Omnologos 