January 14, 2010
Antarctica and the Myth of Deadly Rising Seas
On Monday, scientists from the Norwegian Polar Institute reported that they'd measured sea temperatures beneath an East Antarctic ice shelf and found no signs of warming whatsoever. And while the discovery's corollaries remain mostly blurred by the few rogue mainstream media outlets actually reporting it, the findings are in fact yet another serious blow to the sky-is-falling-because-oceans-are-rising prophecies of the climate alarm crowd.
For years now, alarmists have insisted that Antarctica is thawing thanks to man-made global warming. They warn that such melting of a frozen continent containing 90 percent of all the ice on the planet would inevitably lead to a cataclysmic sea level rise (SLR). Scary stuff, indeed.
However, there are several problems with their assertions, not the least of which is that all evidence of melting selectively focuses on the only area of the continent satellite evidence confirms is warming -- the western region in general, and the Antarctic Peninsula in particular.
But as ICECAP's Joe D'Aleo observed in 2008 [PDF], the relatively small area of the peninsula offers an extremely poor representative sample, as it juts out well north of the mainland into an area of the South Atlantic well known for its "surface and subsurface active volcanic activity." And in the greater scheme, adds D'Aleo, "the vast continent has actually cooled since 1979."
Figure 1. Antarctic Temperature Trend 1982-2004 from Very High Resolution Radiometer (AVHRR) sensors flown on National Oceanic and Atmospheric Administration (NOAA) satellites. Red indicates areas where temperatures generally increased during that period, and blue shows where temperatures predominantly decreased.
Still, carbo-chondriacs blame the "collapse" of ten ice shelves in and around the peninsula on melting of the underside of the ice by global-warming-fueled rising ocean temperatures. And they insist that their models are spot-on in predicting that unless mankind stops pumping CO2 into the atmosphere, it's only a matter of time before the entire continent melts. The effect of such an event, they caution, would be nothing short of a civilization-ending, 57-meter SLR -- a vision normally reserved to biblical fables or the wild imagination of Al Gore.
Of course, narrowly isolated melting doesn't support the hypothesis of widespread polar warming necessary to kindle such horrific images of metropolises submerged by anthropogenic impropriety. That's why locating and denouncing diminishing ice east of the Transantarctic Mountains ranks high on every green-funded researcher's to-do list. And that's also why it would appear that NPI scientists thought they had hit the jackpot when their models calculated that the ice shelves at Dronning Maud Land along Antarctica's northeastern border should be melting at the same rate as those farther west.
So last November, a team from NPI set out to investigate the status of just such a locale -- the Fimbul Ice Shelf. Their stated primary mission: to determine whether ice masses on the shelf are indeed currently on the decline.
Figure 2. This graphic from the project’s website denotes the area of the Fimbul Ice Shelf within the red rectangle. That's the peninsula on the western border of the Weddell Sea, where a number of ice shelves, most recently the Wilkins Ice Shelf, have collapsed into the ocean, fueling unwarranted alarm about runaway melting and sea level rise.
Last month, the expedition drilled its first borehole into the 250-to-400-meter-thick floating ice in order to study the melting and ocean circulation underneath. But readings revealed by the instruments they lowered into the water below were not quite what was anticipated.
In fact, contrary to the warmer, ice-melting temperatures predicted by models, NPI oceanographer and project leader Ole Anders Nøst reported that "the water under the ice shelf is very close to the freezing point." Furthermore, there seemed to have been no change in almost five years:
We observed a roughly 50 meter deep layer of water with temperatures very close to the freezing point, about -2.05 degrees, just beneath the ice shelf. The highest observed temperature was about -1.83 degrees close to the bottom. The temperatures are very similar to temperature data collected by [equipment attached to] elephant seals in 2008 and by British Antarctic Survey using an autosub below the ice shelf in 2005.
Nøst concluded that "This situation seems to be stable, suggesting that the melting under the ice shelf does not increase."
As to the ocean circulation models that incorrectly showed "warm deep water flowing in under the ice shelves," Nøst admitted that "as this is not observed, the models are most likely wrong and should be improved."
Translation: In contrast to model forecasts, Antarctic ice shelf collapse still appears to be isolated to a very tiny area in the western region of a continent otherwise experiencing continued glacial and ice shelf advancement.
And that fact certainly casts further serious doubt on the U.N.'s most recent century-end SLR predictions. Last year, the 18- to 59-centimeter estimate that appeared in the Intergovernmental Panel on Climate Change (IPCC) 2007 Fourth Assessment Report (AR4) was increased to a full two meters, based entirely on fears of accelerated glacial melting in Greenland and Antarctica. Keep in mind that since the prolonged cold snap of the Little Ice Age ended in 1850, the global rate of SLR has remained essentially steady at approximately seven inches per century, due largely to thermal expansion.
Figure 3. SLR since 1880 courtesy of globalwarmingart.com
Reality check time: Does anything in this chart suggest to you that SLR might increase over tenfold -- as the IPCC now predicts -- this century?
As such, is it any wonder that alarmists now claim that even a few degrees of warming will ignite enough accelerated liquefying of the petatons of Earth's surface ice to render the planet barely inhabitable by land-dwellers?
In fact, it was just months after the release of AR4 that the Union of Concerned Scientists offered these hyperactive projections to the 2007 U.N. Framework Convention on Climate Change in Bali:
Sustained warming of [2°C above pre-industrial levels] could, for example, result in the extinction of many species and extensive melting of the Greenland and West Antarctic ice sheets—causing global sea level to rise between 12 and 40 feet.
Readers should be aware that the WAIS sheets UCS referred to are not to be confused with aforementioned ice shelves. While melting "sheets," which predominately lie above bedrock, might contribute to SLR, the ice "shelves" float atop the water and therefore have ostensibly the same impact on SLR frozen as they would melted. There has, however, been concern expressed that melting glaciers might flow faster toward the ocean if unencumbered by the barricading effect of the shelves.
Now, even the notoriously alarmist U.K. Met Office admits that the complete Greenland meltdown to which they'd attribute a seven-meter SLR "would take thousands of years" even if temperatures were to continue to climb. It's therefore quite logical to assume that the majority of the predicted SLR is expected to originate in Antarctica.
And yet, other than select ice shelves (which again are already afloat and would have no further impact upon SLR) in one minuscule area soaking in water warmed by volcanic activity, Antarctica isn't melting at all. And with air temperatures averaging consistently below zero and water temperatures barely above freezing -- even in summer -- nothing in the foreseeable future suggests it might...not even should temperatures, which have been falling since 1998, nonetheless rise to the mostly arbitrary yet internationally alarmist-approved [PDF] catastrophic level of 2°C above pre-industrial levels.
In fact, despite the IPCC insistence that global warming will be most prevalent at the poles, southern-hemisphere sea ice area has remained virtually unchanged since satellite sensors and analytical programs were first capable of measuring it in 1979.
So perhaps when the green-gospel-pronouncing IPCC releases its Fifth Assessment Report, tentatively due for 2014, contributors and lead authors alike might carefully consider the NPI findings, the steady rate of SLR over the past 150 years, and the overall resilience of Antarctic ice before formulating their next soggy doom-and-gloom prophecy. (And don't forget this undeniable fact: Across the continent, the 2008-2009 southern hemisphere summer hosted the lowest Antarctic ice melt in thirty years.)
Surely were these people bound by scientific concerns exclusively, there'd be no doubt whatsoever that they’d do just that.