12 April 2009 - "Greenpeace has yet again ignored scientific reality in the recent misleading claims by its political advisor Geoff Keey about the threatened collapse of the Wilkins Ice Shelf on the Antarctic Peninsula," says Terry Dunleavy of the New Zealand Climate Science Coalition.
"Even while climate campaigners such as Greenpeace, Al Gore and David Suzuki become increasingly shrill in their demands for action on the part of Governments towards the impossible goal of 'stopping climate change', the science that supposedly supports such actions is falling apart," said Mr Dunleavy. "Greenpeace's citation of the threatened collapse of the Wilkins Ice Shelf on the Antarctic Peninsula is a case in point. There is little evidence that such an event is abnormal or unnatural when seen in a significant time perspective and there is even less evidence that human greenhouse gas emissions have anything whatsoever to do with events in the Antarctic."
Leading Canadian climatologist Dr Tim Ball agrees. "Relating the ice shelf deterioration to human activities is an illogical, unsubstantiated, public relations link typical of Greenpeace. As they are always doing, they are taking natural events and presenting them as unnatural.
"Keey's concerns about the speed with which change is occurring in some parts of the Antarctic speaks to the false premise underlying the mistaken view called uniformitarianism - the idea that natural change is gradual over long period of time. In reality, climate change occurs all the time and is often quite rapid, the sudden cooling and then equally sudden warming during the Younger Dryas period ten millennia ago is a case in point. In the space of only about a decade, the Earth cooled as much as five degrees Celsius (perhaps more in some locations such as Greenland), stayed that way for about a millennium and then warmed equally quickly. That warming was about 100 times faster than the modest temperature rise that many believe occurred during the 20th century. Younger Dryas cooling and warming was, of course, entirely natural, occurring before civilization even started, but ignorance of such events allows Greenpeace, Gore and others to claim that sudden climate change today is unnatural. It is not", said Dr Ball.
Referencing a paper in the scientific journal Nature last month, New Zealand Climate Science Coalition member Dr Willem De Lange, of the Earth Sciences faculty at Waikato University, explains that, in the vicinity of the Wilkins Ice Shelf that has so concerned Greenpeace, "there was a rapid rise in air temperature 40-50 years ago [but] it has been fairly stable since then.
"There are many factors involved in the destabilization of an ice shelf," said Dr De Lange. "Warmer ocean waters circulating underneath (moving water melts ice faster than warm air), tidal rises and falls, and wave action all contribute to the fracture and eventually breakup of the ice. Now that the ice shelf is breaking up, it will be possible to sample the underlying sediments and determine the history of the shelf. We do not know if the shelf has undergone cycles of expansion and contraction during the last 10,000 years or has been shrinking since the last glacial period. One thing we do know however is that the break up of this shelf is not solely a consequence of current, or even recent weather changes. It is the consequence of changes over long periods, perhaps 1,000-10,000 years in this case, although we can't tell for certain until the necessary data are collected.
"And an event like the Wilkins Ice Shelf break-up does not provide any evidence as to the causes of the weather conditions that are occurring. Data for similar areas around the West Antarctic Peninsula indicate that changes in glacier and ice shelf mass balances correlate very well with indicators of the activity of the sun, but do not correlate at all with levels of greenhouse gases," concludes Dr De Lange.
Greenpeace's claims were apparently based on statements by British Antarctic Survey Glaciologist Dr David Vaughan. Dr Ball says that statements by Dr. Vaughan about the long time periods taken for ice shelves to build up and the rapid change occurring now were "clearly exploitive because he should know that tabular icebergs break off constantly. Ice close to shore may have indeed been there 'for 10,000 years', as Vaughan claims, but it is not the same ice since it is constantly expanding, the outer portions breaking off and massive ice masses then often floating well up into subtropical latitudes, as happened in November 2006 when icebergs drifted as far north as Canterbury, New Zealand. And, of course, the Wilkins break-up will have negligible direct impact on sea level because the ice is already floating in the ocean.
"Events such as we are seeing in Wilkins Sound today are anything but new. There is one report of a huge drifting 'ice island', 160 km long and 65 km wide - only slightly smaller than the complete Wilkins Ice Shelf - that was circumnavigated in 1840 by a ship sailing to Australia. Log books of sea captains are replete with records of a similar nature over past centuries as well," said Dr. Ball
Dr Ball says the motive that drives some scientists to make sensationalist claims about events such as the Wilkins Ice Shelf break-up is research funding. "Many of these types of statements originate from those whose research is dependent on continued high levels of government funding", says Dr Ball. "Without constantly priming the political pump with a series of excited forecasts about future climate crises, problems that their research is critical to understanding of course, scientists fear much of the funding for their work will simply dry up. Such obvious vested interests should make media and governments strongly suspicions of such forecasts of climate doom."
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