The Arctic climate is changing drastically at a rapid pace and the effects will be felt on a global scale. That was the overall conclusion from a scientific conference on climate changes in the Arctic which was held in Nuuk, Greenland last week. The conference was organized by the National Space Institute at Technical University of Denmark, the Danish Meteorological Institute and the Greenland Climate Center.
The conference showed that the Arctic climate is changing rapidly in a number of different ways:
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The recent rate of decrease in thickness and volume of the Arctic sea ice has been faster than the rate of aerial shrinkage determined from satellites. Given that the present trend of melt continues, some models indicate that it is quite likely that the Arctic Ocean could be ice free in the summer time as early as 2015-16.
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There has been a rapid increase in the mass-loss from the Greenland ice sheet during the last decade. Increased surface melting accounts for around 40% of this increase while iceberg calving from glaciers account for the remaining 60%
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The total mass-loss from the Greenland ice sheet has averaged 240 cubic kilometers of ice per year during the last 5 years. The mass-loss has been accelerating in the last couple of years.
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If the present warming trend continues, melt-water from the Greenland ice sheet will contribute to a sea-level rise of around 1 meter in this century – together with melt-water from other ice sheets and ocean thermal expansion.
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The mass-loss of the ice-sheet at the margins is increasing and spreading north. Up until now, the mass-loss has been concentrated in the southern part of the Greenland ice-sheet. And while the inland part of the ice sheet is still
growing at a small rate each year, this rate is now also declining.
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The warming oceans play a bigger role in melting and accelerating the glacier tongues from the Greenland ice sheet than has previously been thought. Furthermore, melt water from the ice sheet which penetrates the glaciers through crevasses accelerates the outflow by lubricating the bottom of the glacier.
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The permafrost in Greenland as well as globally is warming and in some areas thawing. Currently, construction regulations do not take this into account. Road damage has been observed and further damage on infrastructure is likely in the near future because of these combined effects.
The conference was supported by the National Science Foundation and the Nordic Council of Ministers.
Further information
State geodesist Rene Forsberg, National Space Institute, Technical University of Denmark, (+45) 25402775
Chief adviser Sune Nordentoft Lauritsen, National Space Institute, Technical University of Denmark, (+45) 23743569.