Photo: Patrick Kelley - U.S. Coast Guard
Water flowing into the Arctic Ocean from the North Atlantic is warmer than it has been for at least 2,000 years, in a trend scientists say is likely to produce ice-free summers around the North Pole within only a few years’ time.
Writing in the journal Science, German researcher and lead author Robert Spielhagen says that such a warming in the Fram Strait “is significantly different from all climate variations in the last 2,000 years.”
That body of water between Greenland and Norway’s Svalbard archipelago has warmed about 3.5 degrees Fahrenheit over the past 100 years.
That’s 2.5 degrees warmer than during the Medieval Warm Period, when Vikings farmed in Greenland from about A.D. 900 to 1300.
The report says the warming current is “presumably linked to the Arctic amplification of global warming” and “is most likely another key element in the transition to a future ice-free Arctic Ocean.”
The findings were made by examining ocean sediment cores dating back 2,000 years to determine past water temperatures.
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Water flowing into the Arctic Ocean is 'warmest it's been for more than 2,000 years'
By Daniel Bates
Last updated at 8:26 AM on 3rd February 2011
- Scientists fear temperature rise could lead to an ice-free Arctic, endangering polar bears
Water flowing from the North Atlantic into the Arctic is at its warmest level for more than 2,000 years.
The sea in the Gulf Stream between Greenland and the Norwegian archipelago of Svalbard reached an average of 6C (42F) in recent summers, warmer than at natural peaks during Roman or Medieval times.
Scientists fear the temperature spikes could lead to an ice-free Arctic in years to come and could endanger polar bears, who need the ice in order to survive.
Under threat? Water flowing from the North Atlantic into the Arctic is at its warmest level for more than 2,000 years, potentially endangering polar bears, who need the ice in order to survive
Such changes could also lead to rising sea levels around the world and ‘drastic changes’ to the environment, researchers have concluded.
The latest findings were presented by scientists at the University of Colorado in Boulder who examined tiny plankton-like organisms on the seabed of the Fram strait, which is is the main carrier of ocean heat to the Arctic.
As data from the water only goes back 150 years, they had to drill into sediment on the ocean’s sea bed to find organisms dating back 2,000 years and then analysed their chemical composition to determine past water temperatures.
They found that back then the temperature in the Arctic water was on average 3.4C (38F), but that has now gone up to 5.2C (41F).
Some summer temperatures have gone even higher, hitting 6C (42F) at times.
The scientists concluded that the Arctic water is now warmer than during the Medieval Warm Period, a naturally occurring time of elevated warmth from 900 to 1300AD.
The effect has been obvious and pronounced - according to the University of Colorado's National Snow and Ice Data Centre, ice on the Arctic shrank to its lowest level on record in 2009.
In addition, between 1979 and 2009 an area larger than the state of Alaska disappeared.
'Warmer waters could lead to major sea ice loss and drastic changes for the Arctic'
Higher temperatures ‘are presumably linked to the Arctic amplification of global warming’, the study concluded, adding that global warming ‘is most likely another key element in the transition to a future ice-free Arctic Ocean’.
University of Colorado researcher Thomas Marchitto, a co-author of the study, said that cold seawater ‘is critical for the formation of sea ice, which helps to cool the planet by reflecting sunlight back to space.
‘Sea ice also allows Arctic air temperatures to be very cold by forming an insulating blanket over the ocean.
‘Warmer waters could lead to major sea ice loss and drastic changes for the Arctic.’
He said that the study does not necessarily prove the change is man-made, but it does ‘strongly point toward this being an unusual event’.
‘On a scale of 2,000 years, it stands out dramatically as something that does not look natural,’ he said.
The recent story of a polar bear which swam constantly for nine days and covered 426 miles has been cited by observers as a sign of the dangers to come due to melting ice.
The animal completed its incredible feat around the Beaufort sea in north Alaska but its cub did not make it.
Researchers say that when more sea ice melts it forces polar bears to swim ever greater distances to find a place to rest and hunt.
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