Arctic Climate; Present and future perspective

Ola M. Johannessen

Global warming is enhanced in the Arctic regions. The air temperature has increased to double that of the global average over the last 100 years, the ice cover is decreasing at a rate of 3 - 5% per decade while the thicker multi-year ice is decreasing at a rate of 7 - 10% per decade, the river discharge from Russia is increasing, the tundra-permafrost is thawing and the snow cover on land is decreasing. Furthermore, in the past few years the Greenland ice sheet has lost mass along its edges - more than the accumulation increase in the interior. The Greenland ice sheet is a "wild card" in the global climate system with significant impact on the global sea level rise and a potentially strong impact on the thermohaline circulation (Gulf Stream decrease). However, it should be pointed out that strong natural variability at the interannual time scale takes place in the Arctic region and also causes strong regional variability.

The prediction for the Arctic region is a strong increase in the air temperature and a significant decrease in the ice cover. A blue Arctic Ocean is predicted during the summer time at the end of this century or earlier. However, the many recent IPCC-coupled climate models also indicate a strong wide spread in the result. Recent studies also indicate that most of the annual decrease in ice extent can be "explained" by the increase of CO2 in the atmosphere and that the ice extent is reduced faster than the IPCC models predict.

If the predictions turn out to be valid, then global warming will have a strong impact on the ecosystem and fisheries, living conditions for humans and animals, offshore and onshore oil and gas exploration and production, ship transportation along the Northern Sea Route and North West Passage, on society, economy and energy supply (25% of the remaining oil and gas reserves is estimated to be in the Arctic region). However, it should be pointed out that the IPCC models have not taken into account the potential impact of the increased melting and discharge of fresh water from the Greenland ice sheet - giving increased uncertainty to the predictions. Another important issue which has not been taken into account is the potential increasing uptake of CO2 by a "Blue Arctic Ocean".

Global warming in the Arctic region can have both positive and negative effects. It is easy to understand that a retreating ice cover will make off-shore oil and gas production easier in the future. On the other hand, the thawing of the tundra and permafrost will cause problems for the onshore gas and oil industry. Furthermore, the thawing permafrost will cause a lot of infrastructure problems for the population living in this region. Another big question is what will happen with the huge methane reservoirs which at present are frozen in the permafrost - also located offshore.

These climate changes and the projection of future climate change have also significance in the politics of international relations, in regard to security questions in both the narrow sense and in that of wider human security. The shrinking of the ice cover my allow navigation through Arctic waters and will make for easier access to sea bed resources. This, in turn is already leading to competing claims to sovereignty.  Environmental change will also have a profound effect of the livelihoods of indigenous peoples, both directory and through its implications for the militarization of the region.