September 5, 2007

Antarctica: Warming, Cooling, or Both?

Filed under: Antarctic, Polar

The ice caps are melting – right? If you visit thousands of websites on climate change, watch Gore’s film or many similar documentaries, you would be left with no doubt that the icecaps are warming and melting at an unprecedented rate. However, with respect to Antarctica, you might be surprised when you examine what the United Nations Intergovernmental Panel on Climate Change says in their 2007 Summary for Policymakers. Believe it or not, IPCC reports “Antarctic sea ice extent continues to show inter-annual variability and localized changes but no statistically significant average trends, consistent with the lack of warming reflected in atmospheric temperatures averaged across the region.” Furthermore, they note “Current global model studies project that the Antarctic ice sheet will remain too cold for widespread surface melting and is expected to gain in mass due to increased snowfall.”

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July 17, 2007

Global Warming Debate Upside-Down: Antarctic Update

Filed under: Antarctic, Polar

No presentation of global warming is complete without a visual of some gigantic block of ice moving away from Antarctica – throw in a few penguins looking at the disappearing ice and … it works every time. But is it all true? Is Antarctica warming and melting away? If you consult the latest report of the United Nations’ Intergovernmental Panel on Climate Change (IPCC), you would find statements on the subject in the summary including “Antarctic sea ice extent continues to show inter-annual variability and localized changes but no statistically significant average trends, consistent with the lack of warming reflected in atmospheric temperatures averaged across the region” and “Current global model studies project that the Antarctic ice sheet will remain too cold for widespread surface melting and is expected to gain in mass due to increased snowfall.” Amazing – one would never suspect such conclusions given a cover story in National Geographic titled “THE BIG THAW.”

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January 8, 2007

Antarctic Ice Shelf Melt: Remember the Holocene!

Filed under: Antarctic, Polar

The recent climate change literature contains a great deal of evidence in support of the idea that the high latitudes will experience the greatest atmospheric warming. One of the most rapidly warming regions is the Antarctic Peninsula, and it is no surprise that warming here shortens the spatial and temporal extents of snow cover, glaciers, and sea ice. Ice shelves are not immune from the effects of warming, and rather dramatic ice shelf recession has occurred over periods as short as days and weeks as apparent thresholds in the drivers of melt are surpassed. The break-up of the Larsen-B ice shelf of the Antarctic Peninsula in 2002 received a great deal of worldwide attention, as it was believed that the Larsen-B had remained intact for thousands of years. The volume of glacial melt has prompted some climate change alarmists to push the panic button on global sea level rise. At the front of this crowd is Al Gore, who loves to show images and video footage of falling glacial ice and computer generated representations of inundated coastal areas while claiming that the recent global warming is unprecedented. Such images are meant to generate shock, fear, and a desire to place blame. There is little doubt that warming has indeed occurred across parts of Antarctica over the last few decades. However, let’s consider the possibility that a significant portion of the warming may be natural, and that regions, such as the Antarctic Peninsula, are likely to have experienced as warm or warmer conditions in their climate history, before human emission of greenhouse gases.

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December 5, 2006

Sea Level Rise? - Not From Antarctic Melting

Filed under: Antarctic, Polar, Sea Level Rise

Earth’s polar regions have been loudly touted as evidencing the greatest response to global warming during the last two decades of the 20th century. Likewise, global climate models forecast that the high latitudes will experience the greatest change in temperature should greenhouse gas emissions increase through the 21st century. The warming supposedly has and will cause large-scale glacial melt and an input of fresh water that will produce global sea level rise and a breakdown of the fundamental worldwide oceanic circulation. These aspects of potential climate change serve as great talking points for alarmists, as they portray inundated coastal areas and a Europe subject to Arctic-like winters as in the movie Day After Tomorrow.

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October 11, 2006

Antarctic Ice Sheet (and the Plot) Thickens

Filed under: Antarctic, Glaciers/Sea Ice, Polar

Glaciers the size of Rhode Island breaking off and floating away…grass growing along the periphery of Antarctica…coastal inundation from rising sea levels…even a forecast that Europe will freeze solid the “day after tomorrow.” These are a few of the doomsday portraits painted by a politicized few that are clamoring to have a full-throated voice in the great global climate change debate.

Evidence that lends support to some of the theories behind these supposedly dire portraits can be found throughout the scientific literature, as is the case with many of the issues in the debate about the warming of the global atmosphere. In reference to the scenes described above, many studies have presented measured and modeled data that suggest that the greatest amount of atmospheric warming is occurring or will occur across Earth’s polar regions. However, one can just as easily search the literature and find conflicting evidence.

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March 24, 2006

No News is Bad News

There is not much new in a collection of articles about global warming and sea level rise in the latest issue of Science. As such, it is mostly recycled and repackaged information that the head of the American Association for the Advancement of Science (AAAS), Donald Kennedy, can take down from New York Avenue in DC to Capitol Hill, to scare politicians into doing what it wants, which is an immediate cap on U.S. emissions of carbon dioxide.

Never mind that even a 25% reduction will have an undetectable effect on the rate of global temperature rise in the foreseeable future, and that it will cost a lot. Science crammed its March 24th issue with five articles (including commentary and editorials) devoted to melting ice and sea level rise—including one (Overpeck et al., 2006) which proclaims “[I]t is highly likely that the ice sheet changes described in this paper [leading to an—egad—global sea level a rise of 12-18 feet] could be avoided if humans were to significantly reduce emissions early in the current century” is hardly surprising.

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March 3, 2006

Antarctic Ice: The Cold Truth

Filed under: Antarctic, Polar, Sea Level Rise

This week Science Magazine’s on-line SciencExpress reports that Antarctica has been losing large amounts of ice mass over the past three years, contributing to sea level rise at a rate of 0.4 ± 0.2 mm/year. This comes on the heels of a paper published by Science two weeks ago that reported that Greenland was also losing big chunks of ice and contributing to sea level rise at a rate of 0.57 mm/yr.

If this sounds like one of those repeating news stories — Coup in Haiti, Osama Sends a Tape, etc. — it is. And so is the response. Natural variability is sufficiently large on yearly and multidecadal time scales that it is simply impossible to conclude that anything other than natural variability is at play in either of these two stories.

(Read more at Tech Central Station)




May 27, 2005

Antarctic Ice: A Global Warming Snow Job?

Climate scientists have long suspected that warming the oceans around a very cold continent is likely to dramatically increase snowfall. Consider Antarctica. It’s plenty chilly, dozens of degrees below freezing, and it’s surrounded by water. The warmer the water, the greater the evaporation from its surface, and, obviously, the more moisture it contributes to the local atmosphere.

So, when this moisture gets swirled up by a common cyclone, do you think it’s going to fall as rain in Antarctica?

A recent study, no shocker to real climatologists (but perhaps to climate doomsayers), demonstrates this simple physics. It appears in the latest SciencExpress, and it shows that the vast majority of the Antarctic landmass is rapidly gaining ice and snow cover.
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April 22, 2005

The Tip of the Iceberg: Yet another Predictable Distortion

This Earth Day, AP newswire leads with a real scare story: “Study Shows Antarctic Glaciers Shrinking.” In doing so, the press, yet again, predictably distorted a global warming story.

By “Antarctica” they actually meant the Antarctic Peninsula, which comprises about 2% of the continent. It’s warming there and has been for decades. But every scientist (or for that matter, everyone who has read Michael Crichton’s State of Fear) knows that the temperature averaged over the entire continent has been declining for decades.

The underlying science behind the AP story was published in the April 22, 2005 issue of Science magazine, under the more appropriate (and accurate) title, “Retreating Glacier Fronts on the Antarctic Peninsula over the Past Half-Century.” A research team led by Alison Cook of the British Antarctic Survey carefully measured the historical position of 244 glaciers as determined from a 60-year collection of images including aerial photographs and satellite pictures. By comparing the position of glacier termini over time, the researchers were able to determine the timing and speed of glacial changes.

The results presented in Science weren’t even based on the entire Peninsula, but rather the northern portion. While a more comprehensive continent-wide investigation of coastal glacier changes is underway, only the results from the Peninsula were written up.
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January 4, 2005

In with the new, out with the old?

We had hoped that in the New Year scientists would stop hyping global warming to reporters such as the Washington Post’s new global warming specialist Juliet Eilperin. Our hopes were dashed on January 3.

The headline in the January 3, 2005 Science Notebook section of the Washington Post read “New Theory of Antarctic Ice Cap.” It began, “A sharp drop in the atmospheric concentration of carbon dioxide 34 million years ago helped form the mile-thick ice sheet now covering Antarctica.” The article, penned by Post science writer Juliet Eilperin, referred to a recently published paper by a research team led by Purdue University’s Matthew Huber.

Amazing. Huber’s article was not about carbon dioxide and Antarctic climate. Rather, it discusses whether a shift in oceanic circulation patterns brought about by the separation of Antarctica from Australia some 35 million years ago (a consequence of continental drift), led to a subsequent cooling of Antarctica and ice sheet growth.
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