Greenhouse Gases Blamed for Higher Arctic Temperatures in the Last Century

First Posted: Oct 28, 2013 11:07 AM EDT

A recent study claims that the average Eastern Canadian Arctic temperatures have been higher in the past one century than in the last 120,000 years.

This study was conducted by the University of Colorado Boulder, led by Gifford Miller, a geological sciences professor. The researchers found that in the early Holocene period, the Sun's energy showered over the region was about 9 percent greater than what it is today.  

The present temperatures prevailing over the Eastern Canadian Arctic surpassed the peak warmth, which existed over the region in the early Holocene or early geological period, when the Sun's energy was about 9 percent more. This geological epoch commenced after Earth's last glacial period got over, approximately 11,700 years ago and is still continuing.

"The key piece here is just how unprecedented the warming of Arctic Canada is," Prof. Miller said in a press release. "This study really says the warming we are seeing is outside any kind of known natural variability, and it has to be due to increased greenhouse gases in the atmosphere."

The researchers estimated the Arctic temperatures by examining the clumps of dead mosses and trapped gas bubbles in the ice caps on Baffin Island.

The method of radioactive dating, also called radiometric dating, was used on these mosses by the researchers and it was found that the mosses were entrapped in the ice since 44,000 to 51,000 years. Radiometric dating refers to a method of dating any material on the basis of the decay of the radioactive atoms present in it. This process is able to date around 50,000 years precisely. These findings pointed toward the temperatures being higher than what they were 120,000 years back

 "Although the Arctic has been warming since about 1900, the most significant warming in the Baffin Island region didn't really start until the 1970s," said Miller. "And it is really in the past 20 years that the warming signal from that region has been just stunning. All of Baffin Island is melting, and we expect all of the ice caps to eventually disappear, even if there is no additional warming," Miller concluded.

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