What do glaciers indicate? Much more than the local (or maybe even global!) temperature trends. In fact, read what The Register reports about the Pine Island Glacier (PIG) in Antarctica:
[…] The PIG has flowed more and more rapidly into the Amundsen Sea since scientists have begun monitoring it, adding fresh water to the world’s oceans. […] Many scientists have theorised that the PIG’s accelerating flow is due to global warming. However, recent research [indicates] that the PIG’s ice flow formerly ground its way out to sea across the top of a previously unknown rocky underwater ridge, which tended to hold it back. Many years ago, however, before the area was surveyed in much detail, the glacier’s floating outflow sheet separated from the ridge top which it had been grinding away at for millennia and so picked up speed. This also allowed relatively warm sea water to get up under the sheet and so increase melting and ease of movement. […]
As luck has it, around three years ago I did myself some research about the Upsala glacier in Patagonia, used by The New York Review of Books to illustrate an article by Bill McKibben. The juxtaposition of photographs of Upsale taken respectively in 1928 and 2004 was captioned along the lines of “most of the glacier [has] melted“.
As usual, it didn’t take much to find out how wrong the caption was – most of the Upsala glacier has not melted at all (a correction was published by the NYRB a few weeks later).
More interestingly though, what I did find were scholarly references attributing the glacier’s retreat to mechanical rather than climatic stresses, just as now for Pine Island’s. In other words, an understanding of glaciers like of everything else can’t be confined to quick glances at photographic “evidence”. Without a proper field study, and without a complete analysis of the situation, “global warming” has becoming the ultimate refuge for the climate (scientific) scoundrels.
Let’s hope the one thing that will come out of all these years of blacklists, tricks, and less-than-sincere “peer” review is a meme about the true complexity of the planet, to be studied with care and maybe even awe instead than in order to support one’s pet political project.
Indeed: “There are more things in heaven and earth, Horatio, than are dreamt of in your philosophy.”