10 May 2011

Rapid Change in the Arctic

The Arctic Monitoring and Assessment Program (AMAP) has issued its latest Snow, Water, Ice and Permafrost in the Arctic report (SWIPA), with recent data on changes in the arctic and how they will affect us all.

The major finding is that changes the Arctic is changing faster than previously projected. The report calls attention to the social and economic implications of these changes. But most of us don't live in the Arctic, so why should we care what happens up there?

Sea Level

Many news reports (see two examples below) have focused on the statement that sea levels will rise up to 1.6 meters above 1990 levels by 2100. This is not strictly a finding of the SWIPA study. In fact it just quotes other model results, saying:
High uncertainty surrounds estimates of future global sea level. Latest models predict a rise of 0.9 to 1.6 m above the 1990 level by 2100, with Arctic ice making a significant contribution.
SWIPA itself doesn't say why this warming is happening, but agrees with the IPCC:
In attributing the cause of warming in the Arctic, SWIPA refers to the findings of the Fourth Assessment Report from the Intergovernmental Panel on Climate Change (IPCC). This states that "Most of the observed increase in global average temperatures since the mid-20th century is very likely [> 90% probability] due to the observed increase in anthropogenic GHG [greenhouse gas] concentrations".
It does conclude, however, that "melting glaciers and ice sheets worldwide have become the biggest contributor to global sea level rise," and that "These contributions from the Arctic to global sea level rise are much greater than previously measured."

Key Findings

The English executive summary is in PDF here. The key findings it lists are:
  1. "The past six years (2005–2010) have been the warmest period ever recorded in the Arctic."
  2. "Snow and sea ice are interacting with the climate system to accelerate warming" (positive feedbacks--see finding 12 below).
  3. "The extent and duration of snow cover and sea ice have decreased across the Arctic. Temperatures in the permafrost have risen by up to 2 °C. The southern limit of permafrost has moved northward in Russia and Canada."
  4. "Multiyear sea ice, mountain glaciers, ice caps and the Greenland Ice Sheet have all been declining faster since 2000 than they did in the previous decade."
  5. "Model projections reported by the Intergovernmental Panel on Climate Change (IPCC) in 2007 underestimated the rates of change now observed in sea ice."
  6. "Average snow cover duration is projected to decline by up to 20% by 2050."
  7. "The Arctic Ocean is projected to become nearly ice-free in summer within this century, likely within the next thirty to forty years."
  8. These and other changes are altering "the characteristics of Arctic ecosystems and in some cases loss of entire habitats. This has consequences for people who receive benefits from Arctic ecosystems."
  9. "The observed and expected future changes to the Arctic cryosphere impact Arctic society on many levels," creating both threats and opportunities.
  10. "Transport options and access to resources are radically changed by differences in the distribution and seasonal occurrence of snow, water, ice and permafrost."
  11. "Arctic infrastructure faces increased risks of damage."
  12. "Loss of ice and snow in the Arctic enhances climate warming by increasing absorption of the sun’s energy at the surface of the planet. It could also dramatically increase emissions of carbon dioxide and methane and change large-scale ocean currents."
  13. "Arctic glaciers, ice caps and the Greenland Ice Sheet contributed over 40% of the global sea level rise of around 3 mm per year observed between 2003 and 2008. In the future, global sea level is projected to rise by 0.9–1.6 m by 2100 and Arctic ice loss will make a substantial contribution to this."
  14. "Everyone who lives, works or does business in the Arctic will need to adapt to changes in the cryosphere", and this will require significant investment.
  15. Considerable uncertainty remains and more research is needed. (The traditional coda to any scientific report.)

About AMAP

The Arctic Monitoring and Assessment Programme is a leading, authoritative, scientific program to understand what is going on in the arctic:
AMAP is an international organization established in 1991 to implement components of the Arctic Environmental Protection Strategy (AEPS).

Now a programme group of the Arctic Council, AMAP's current objective is "providing reliable and sufficient information on the status of, and threats to, the Arctic environment, and providing scientific advice on actions to be taken in order to support Arctic governments in their efforts to take remedial and preventive actions relating to contaminants".
So its findings carry considerable weight.

Reuters story

Huffington Post story