Comments
Greenland’s Ice Armageddon on Hold
Richard Kerr of Science magazine reports on a presentation at the recent fall meeting of the American Geophysical Union in a News Focus article entitled: ‘Galloping Glaciers of Greenland Have Reined Themselves In’
Ice loss in Greenland has had some climatologists speculating that global warming might have brought on a scary new regime of wildly heightened ice loss and an ever-faster rise in sea level. But glaciologists reported at the American Geophysical Union meeting that Greenland ice’s Armageddon has come to an end.
So much for Greenland ice’s Armageddon. “It has come to an end,” glaciologist Tavi Murray of Swansea University in the United Kingdom said during a session at the meeting. “There seems to have been a synchronous switch-off” of the speed-up, she said. Nearly everywhere around south east Greenland, outlet glacier flows have returned to the levels of 2000. An increasingly warmer climate will no doubt eat away at the Greenland ice sheet for centuries, glaciologists say, but no one should be extrapolating the ice’s recent wild behavior into the future.
Kerr didn’t cover the Knappeneberger et al (of World Climate Report) presentation entitled, ‘A Reconstructed 1784-2007 Time Series of Greenland Melt Extent.’
The Abstract states:
Total melt on the Greenland ice sheet has been rising over the past several decades. The melt extent observed in 2007 was the greatest on record according to several satellite-derived indices of Greenland melt. Observed melt extent across the Greenland ice sheet has been shown to be strongly related to summer station temperatures from locations along Greenland’s coastal periphery, as well as to variations in the circulation of the atmosphere across the North Atlantic. We exploit these relationships with historical temperature and circulation observations to develop a 224-yr reconstructed history of annual Greenland melt extent from the late 18th century to 2007. This reconstruction allows us to put recent melt, particularly 2007, into a historical perspective and compare current melt to the well-known warm period in the early half of the 20th century. Our reconstruction indicates that the melt observed since the late 1990s is likely among the highest extents to have occurred since the late 18th century, although recent values are not statistically different from those common during the period 1923-1961, a time when summer temperatures along the southern coast of Greenland were similarly high as those experienced in recent years. The reconstruction indicates that if the current trend toward increasing melt extent continues, total melt across the Greenland ice sheet will exceed historic values of the past two and a quarter centuries.
January 26th, 2009 at 12:31 pm
[...] A Reconstructed 1784-2007 Time Series of Greenland Melt Extent We exploit these relationships with historical temperature and circulation observations to develop a 224-yr reconstructed history of annual Greenland melt extent from the late 18th century to 2007. This reconstruction allows us to put recent melt, particularly 2007, into a historical perspective and compare current melt to the well-known warm period in the early half of the 20th century. Our reconstruction indicates that the melt observed since the late 1990s is likely among the highest extents to have occurred since the late 18th century, although recent values are not statistically different from those common during the period 1923-1961, a time when summer temperatures along the southern coast of Greenland were similarly high as those experienced in recent years. The reconstruction indicates that if the current trend toward increasing melt extent continues, total melt across the Greenland ice sheet will exceed historic values of the past two and a quarter centuries. [...]
January 27th, 2009 at 1:22 am
[...] and Greenland’s Ice Armageddon on Hold [...]
May 6th, 2009 at 1:48 am
[...] for a wake-up call was genuine for the polar and glacial regions. He apparently didn’t read this paper from last Autumn’s AGU Meeting Ice loss in Greenland has had some climatologists speculating [...]