Temperatures in Canadian Arctic at 44,000-year high

BY Agencies26 Oct 2013 5:38 AM IST

The average summer temperatures in the Canadian Arctic over the last century are the highest in the last 44,000 years, and perhaps as long ago as 120,000 years, a new study has found.

The study is the first direct evidence the present warmth in the Eastern Canadian Arctic exceeds the peak warmth there in the Early Holocene, when the amount of the Sun’s energy reaching the Northern Hemisphere in summer was roughly 9 per cent greater than today, researchers said.

The Holocene is a geological epoch that began after Earth’s last glacial period ended roughly 11,700 years ago and which continues today.

University of Colorado, Boulder geological sciences Professor Gifford Miller and colleagues used dead moss clumps emerging from receding ice caps on Baffin Island as tiny clocks.

At four different ice caps, radiocarbon dates show the mosses had not been exposed to the elements since at least 44,000 to 51,000 years ago.

‘The key piece here is just how unprecedented the warming of Arctic Canada is,’ said Miller, the study leader.
‘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,’ he said.

Miller and colleagues compiled the age distribution of 145 radiocarbon-dated plants in the highlands of Baffin Island that were exposed by ice recession during the year they were collected by the researchers.

All samples collected were within 1 meter of the ice caps, which are generally receding by 2 to 3 metres a year.

Temperatures in Canadian Arctic at 44,000-year high

Agencies

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