Arctic Climate Change
A report to be presented next week at the 7th Arctic Council Ministerial Meeting by the Arctic Monitoring and Assessment Program is the latest evidence in how climate change is impacting the Arctic. The so-called SWIPA Assessment is the most comprehensive compilation of scientific knowledge on the changes in the Arctic’s frozen parts within the past 6 years.
The report states that the observed changes in sea ice in the Arctic Ocean, in the mass of the Greenland ice sheet and in Arctic icecaps over the past ten years are dramatic and represent an obvious departure from the long-term patterns.
The warming of the Arctic, due to climate change, has been twice as high as the world average since 1980. Surface air temperatures in the Arctic since 2005 have been higher than for any five year period since measurements began around 1880. Arctic summer temperatures have been higher in the past few decades than at any time in the past 2000 years.
To make matters worse, the report also confirms that snow and sea ice are interacting with the climate system to accelerate warming. Average snow cover duration is projected to decline by up to 20% by 2050. As the light colored snow and sea ice melts, darker ocean and land takes over. And darker land or ocean surfaces absorb more of the sun’s energy, which in turn leads to further warming of the Earth’s surface and the air above.
Temperatures in the permafrost have risen by up to 2 degrees Celsius, and thawing permafrost causes deformation of buildings and infrastructure, which will cause some communities to relocate. The southern limit of permafrost has moved northward in Russia and Canada. Further, nearly all glaciers and ice caps in most Arctic regions have been declining faster since 2000 than they did in the previous decade.
Average winter temperatures are projected to increase even more in the future, averaging between 3 and 7 degrees Celsius warmer by 2080, in what will be a shorter winter season. The Arctic mountain glaciers and ice caps are projected to lose between 10% and 30% of their total mass by 2100. And the Arctic Ocean is predicted to be nearly ice free in summer during this century, likely as soon as the next 30 to 40 years. This is bad news for animals such as the polar bear. Changes in the ice and snow cause fundamental changes to the characteristics of Arctic ecosystems and in some cases loss of entire habitats. This also has consequences for people who receive benefits from Arctic ecosystems.
Loss of ice and snow in the Arctic also increases emissions of carbon dioxide and methane and change large scale ocean currents.
As the Arctic sea ice diminishes during summer, accessibility to the Arctic minerals, energy resources, and sea routes will increase. This will bring economic benefits even as it changes the landscape.
Adaptation also requires leadership from governments and international bodies, and increased investment in infrastructure. The SWIPA Assessment will be formally presented to the 7th Arctic Council Ministerial Meeting in Nuuk, Greenland on May 12, 2011.