November 7, 2007
‘Big Thaw,’ a summertime spectacular in National Geographic magazine, provided awesome scenes of climate-change catastrophes.
The glaciers are melting. The ice sheets are melting. They’re sliding rapidly out to sea. More rapidly than anyone imagined. Look for the ice sheets to collapse. Look for sea levels to rise. Etc. Etc.
National Geographic’s breathless account, brilliantly illustrated with the stunning photography for which it is famous, won headlines around the world. It has been dramatized and magnified on nightly newscasts and blogs alike, and has become a staple in the popular imagination.
But it won’t happen, says Prof. Cliff Ollier of the University of Western Australia. “Rapid melting of the Greenland and Antarctic ice sheets is impossible.”
The National Geographic descriptions, on their face, seem plausible. “Ice seems rock hard when you crunch an ice cube or slip on a frozen puddle. But when piled in a great mass, ice oozes like slow, cold taffy,” the article explained. “On Greenland, it flows outward from the heart of the ice sheet, a dome of ice the size of the Gulf of Mexico … Four miles [six kilometres] wide and several thousand feet thick, Jakobshavn is an icy Amazon, disgorging more ice than any other Greenland glacier.”
The article described fast-flowing glaciers such as Greenland’s Jakobshavn. “In the past decade it doubled its speed, to roughly 120 feet [37 meters] a day. By now it discharges 11 cubic miles [45 cubic kilometres] of ice each year, jamming the fjord with fresh icebergs. As a result, Greenland lost 54 cubic miles of ice in 2005, more than twice as much as 10 years ago–“and more than some scientists were prepared to believe.”
More alarmingly, the article reports that Greenland’s ice sheet is starting to stir — satellites have detected a weakening of Greenland’s gravity –and that the same stirring may be occurring in Antarctica. The article describes a thinning Antarctic ice plain “of dead-flat ice” that in the next decade will be thin enough to float free.
“Once that happens and the ocean intrudes, a chain reaction of collapse could follow,” the National Geographic article continues. “The bed is very deep and flat for the next 150 miles inland, so an enormous fjord would be created in the ice … That would put the nail in the coffin — it would go on accelerating, retreating, and drain a lot of that part of West Antarctica.”
All this, Prof. Ollier explains, is nonsense. The scenarios raised in the National Geographic article stem from models divorced from the real world. They rely on imaginary glaciers and ice sheets — not on the actual formations that exist in Greenland and Antarctica — and demonstrate no understanding of how glaciers flow.
As one example, the models rely “on the concept of an ice sheet sliding down an inclined plane on a base lubricated by meltwater, which is itself increasing because of global warming,” Prof. Ollier explains. “In reality, the Greenland and Antarctic ice sheets occupy deep basins, and cannot slide down a plane.”
Ice sheets, which can extend to a depth of several kilometres below the surface, can melt at their base — the warmest part of the ice sheet, due to the heat of the Earth. The drilling of ice cores, revealing complete records of depositions over periods of hundreds of thousands of years, show that the ice sheets have accumulated without melting, even when temperatures have been warmer than now.
“Ice sheets do not melt from the surface down — only at the edges,” Prof. Ollier explains. The modellers’ mechanism that has “meltwater lakes on the surface finding their way down through cracks in the ice and lubricating the bottom of the glacier is not compatible with accumulation of undisturbed snow layers.”
In truth, the rate of ice flow now seen in the polar regions does not depend on the present climate, but on the accumulation of ice that occurred in the distant past. Neither is today’s warming extraordinary: “Arctic explorers used to get their ships a lot closer to northern Green-land than you could now,” he explains.
The records “do not fit the model of surface melting, even infrequently. After three-quarters of a million years of documented continuous accumulation, how can we believe that right now the world’s ice sheets are collapsing!” ‘The Big Thaw’ is a Big Saw.
— – Lawrence Solomon is executive director of Energy Probe and the Urban Renaissance Institute. www.urban-renaissance.org
CV OF A DENIER:
Dr. Cliff Ollier, a geologist, geomorphologist and soil scientist, is emeritus professor and honorary research fellow, University of Western Australia. He has authored or co-authored more than 500 publications, mostly in world-class journals, and 10 books, including the widely acclaimed Tectonics and Landforms and The Origin of Mountains. He received his doctorate from Bristol University.