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Earth’s poles are shifting because of climate change

“Climate change is causing the North Pole’s location to drift, owing to subtle changes in Earth’s rotation that result from the melting of glaciers and ice sheets.

Computer simulations had suggested that the melting of ice sheets and the consequent rise in sea level could affect the distribution of mass on the Earth’s surface. This would in turn cause the Earth’s axis to shift, an effect that has been confirmed by measurements of the positions of the poles.

Jianli Chen of the University of Texas at Austin and colleagues have shown that melting due to our greenhouse-gas emissions is making its own contribution to the shift. …”Ice melting and sea level change can explain 90 per cent of the [eastward shift],” says Chen. “The driving force for the sudden change is climate change.””

Greenland’s ice sheets are disappearing faster than anyone predicted

“Climatologist Jason Box has a radical theory why…

In 2009, he announced the Petermann glacier, one of the largest in Greenland, would break up that summer – a potent sign of how fast the Arctic was warming. Most glaciologists thought he was nuts – especially after the summer passed and nothing happened. In 2010, however, Petermann began to calve; two years later, it was shedding icebergs twice the size of Manhattan. Another example: In early 2012, Box predicted there would be surface melting across the entirety of Greenland within a decade. Again, many scientists dismissed this as alarmist claptrap. If anything, Box was too conservative – it happened a few months later. He also believes that the climate community is underestimating how much sea levels could rise in the coming ­decades.

…Box decided to return to Greenland this summer – his 24th trip here in the past 20 years – to test a more startling hypothesis, part of what he calls “a unified theory” of glaciology: that tundra fires in Canada, massive wildfires in Colorado and pollution from coal-fired power plants in Europe and China had sent an unexpectedly thick layer of soot over the Arctic region last summer, which settled onto Greenland’s vast frozen interior, increasing the amount of sunlight the snow and ice absorbed, which in turn accelerated the melting.”

Ice sheets melting at poles faster than before

“Fueled by global warming, polar ice sheets in Greenland and Antarctica are now melting three times faster than they did in the 1990s, a new scientific study says.”

Unprecedented May Heat In Greenland

“The record books for Greenland’s climate were re-written [last] Tuesday, when the mercury hit 24.8°C (76.6°F) at Narsarsuaq, Greenland, on the southern coast. According to weather records researcher Maximiliano Herrera, this is the hottest temperature on record in Greenland for May, and is just 0.7°C (1.3°F) below the hottest temperature ever measured in Greenland. The previous May record was 22.4°C (72.3°F) at Kangerlussuaq (called Sondre Stormfjord in Danish) on May 31, 1991. The 25.2°C at Narsarsuaq on June 22, 1957 is the only June temperature measured in Greenland warmer than yesterday’s 24.8°C reading. Wunderground’s extremes page shows that the all-time warmest temperature record for Greenland is 25.5°C (77.9°F) set on July 26, 1990.”

Greenland ice sheet may melt completely with 1.6 degrees global warming

“The Greenland ice sheet is likely to be more vulnerable to global warming than previously thought. The temperature threshold for melting the ice sheet completely is in the range of 0.8 to 3.2 degrees Celsius global warming, with a best estimate of 1.6 degrees above pre-industrial levels, shows a new study by scientists from the Potsdam Institute for Climate Impact Research (PIK) and the Universidad Complutense de Madrid. Today, already 0.8 degrees global warming has been observed. Substantial melting of land ice could contribute to long-term sea-level rise of several meters and therefore it potentially affects the lives of many millions of people.”

Extreme melting on Greenland ice sheet

Extreme melting on Greenland ice sheet, reports CCNY team :

Ice Loss Accelerates in Greenland, Antarctica, NASA Study Finds

March 9, 2011 – Original Source: Bloomberg

Greenland and Antarctica’s ice sheets are shrinking more quickly, suggesting United Nations projections for sea-level rise are too conservative, a U.S. National Aeronautics and Space Administration-funded study said.

From 1992 to 2009, the two regions lost on average 36.3 billion tons more ice every year than the previous year, scientists led by Eric Rignot at NASA’s Jet Propulsion Laboratory in Pasadena, California, said in a study in the Geophysical Research Letters journal. The researchers said they linked two independent sets of measurements to validate them.

Continuing the trend may raise oceans 15 centimeters (6 inches) from 2010 to 2050, and by 56 centimeters by 2100, the study said. That’s more than what was factored into the 2007 projection by the UN’s Intergovernmental Panel on Climate Change for seas to rise 18 to 59 centimeters by 2100.

“If present trends continue, sea level is likely to be significantly higher than levels projected by the United Nations,” Rignot said in a statement e-mailed late yesterday by NASA. “Our study helps reduce uncertainties.”

The UN prediction also includes the expansion of water with warmer temperatures and the melting of mountain glaciers and smaller ice caps.

The researchers said their 2050 forecast has a margin of error of 2 centimeters. Melting from mountain glaciers and smaller ice caps would add 8 centimeters to the sea level increase. The expansion of water as temperatures rise would add 9 centimeters, the researchers said.

They warned their 2100 figure can’t be considered a projection because of “considerable uncertainty in future acceleration of ice sheet mass loss.”

‘Surprising’ Acceleration

The IPCC in 2007 said Greenland and Antarctica contributed a combined 0.42 millimeters a year to sea level rise from 1993 through 2003. That’s just over half the 0.77-millimeter contribution from mountain glaciers and smaller ice caps, and a quarter of the 1.6-millimeter rise as a result of water expanding with warmer temperatures.

The North Atlantic island and southern continent now contribute more than mountain glaciers and ice caps, according to the NASA study. The researchers cited another paper that put the ice loss of the glaciers and ice caps at 402 billion tons in 2006, compared with the 475 billion tons from Greenland and Antarctica in the same year — equivalent to 1.3 millimeters of sea level rise. The acceleration in ice loss is three times greater than for mountain glaciers, they wrote.

“That ice sheets will dominate future sea level rise is not surprising — they hold a lot more ice mass than mountain glaciers,” said Rignot, also a researcher at the University of California, Irvine. “What is surprising is this increased contribution by the ice sheets is already happening.”

Utrecht University in the Netherlands and the National Center for Atmospheric Research in Boulder, Colorado, also contributed to the research. The scientists correlated different sets of satellite, radar and climate modeling data to produce the study.

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