Text: climate and polar researcher (Ph.D. and Post Doc.) Sebastian H. Mernild, MARCH 2008
University of Alaska Fairbanks, Fairbanks, Alaska, USA
Increasing temperatures, higher precipitation and higher humidity are facts. During the last 100 years, the temperature on the planet has risen by between 0.3 and 0.6 degrees Celsius. Since the end of the »little ice-age« around 1920 and up to today, the temperature has risen in the Arctic, most notably since the 1970’s.
The situation today is different than it was 70-80 years ago and there are strong indications that this time – as opposed to before – the warming will continue to increase. Rising temperatures are being followed by a precipitation increase of 1 per cent per decade and by an increase in humidity of over 2 per cent over the past 30 years.
Precipitation in the Arctic is increasing and coming in the form of rain instead of snow. The increased temperatures and the increased precipitation mean that the idyllic pictures of a white Greenland and a white North Pole are changing to a greener Greenland and a blue North Pole.
More snow free periods in the Arctic
Climate change is causing a transformation of the planet, especially the delicate Arctic environment. The mutual influences of the atmosphere (troposphere), the earth and the surface of the sea have, over the past 10-15 years, changed a series of cryospheric (ice, snow, permafrost and sea ice) conditions in the Arctic environment.
The changed climate has brought about an extension of the period of thaw by be-tween 50-60 days and of the snow-free period of 14-40 days. In 2007, the part of ice sheet that lies above a height of 2,000 metres suffered record-high melt off. The melt off for 2007 was 97% greater than average for the period 1995–2006.
In 2007, the melt area was equal to 50% of the inland ice’s area, or 22 times the size of Denmark (about 953,600 km2). In 1996, the melt area was equal to only 28% of the area of the inland ice, or 12 times the size of Denmark (about 518,600 km2).
Melting ice cover the animal food sources
Where plants and animals could previously rely on frost and stable snow cover from September to May, there will now be many periods of thaw during the winter months, causing the snow to melt, with icing over of vegetation and snow to follow.
This would cause life-threatening problems for some plant and animal life, like for example musk-oxen. They are not found in South East Greenland because the climate here is maritime. On the other hand, the growth season for plants is expected to start earlier. The consequences of climate change are countless and farreaching.
Some of the consequences are harder to assess than others. As an expert, I think the tendency is worrying. The countdown to the greatest political challenge of our time has started.