Indicator Specification

Arctic sea ice

Indicator Specification
  Indicator codes: CLIM 010
Published 08 Sep 2008 Last modified 25 Aug 2017
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Average extent of arctic sea ice in March and September 1979-2007 Area of multi-year Arctic sea ice in March 1957-2007 Observed and projected Arctic September sea-ice extent 1900-2100

Update planned for November 2012

Assessment versions

Published (reviewed and quality assured)
  • No published assessments


Justification for indicator selection

Reduction in Arctic sea ice has several feedbacks to the climate system. Snow-covered ice reflects 85 % of the sunlight (high albedo), whereas open water reflects only 7 % (low albedo). Less ice and snow will therefore accelerate both sea-ice decline and global warming. Reduced ice formation will also reduce the formation of dense deep water which contributes to driving ocean circulation. As the ice cover influences air temperature and the circulation of air masses, changes in weather patterns such as storm tracks and precipitation can be expected even at mid-latitudes (Serreze et al., 2007). Warming over the Arctic Ocean can also penetrate into the surrounding continents, raising concern about thawing of the permafrost with release of additional greenhouse gasses (Lawrence et al., 2008).
The sea ice is an ecosystem filled with life uniquely adapted to these conditions, from micro-organisms in channels and pores within the ice, rich algal communities underneath, to fish, seals, whales and polar bears. The diversity of life in the ice usually grows with the age of the ice floes. As the ice gets younger and smaller, the abundance of ice-associated species will be reduced, with a risk of extinction for some of them. Indigenous Arctic peoples adapted to fishing and hunting will face large economic, social and cultural changes.
Less summer ice will ease access to the Arctic Ocean's resources, though remaining ice will still pose a major challenge for operations most of the year. Expectations of large undiscovered oil and gas resources are already driving the focus of the petroleum industry and governments northwards. As marine species move northwards with warmer sea and less ice, so will the fishing fleet. It is however hard to tell whether the fisheries will become richer or not; fish species react differently to changes in marine climate, and it is hard to predict whether the timing of the annual plankton blooms will continue to match the growth of larvae and young fish. Shipping and tourism are likely to increase, although drift ice, short sailing seasons and lack of infrastructure will impede a rapid development of transcontinental shipping of goods; it is more likely that traffic linked to extraction of Arctic resources on the fringes of the Arctic sea routes will grow first. These activities offer new economic opportunities. At the same time they represent new pressures and risks to an ocean that has so far been closed to most economic activities by the ice. This should be met by better international regulations of these activities.
High interest in getting access to the resources in the Arctic may create tensions and security problems. However most borders in the Arctic Ocean have been drawn, thereby clearly defining who has the ownership to the resources and right to manage them. In the remaining unresolved issues of delimitation of the Exclusive Economic Zones and extended continental shelves, all the coastal states of the Arctic Ocean follow the procedures of the UN Convention of the Law of the Seas.

Scientific references

  • No rationale references available

Indicator definition

  • Average extent of arctic sea ice in March and September 1979-2007
  • Area of multi-year Arctic sea ice in March 1957-2007
  • Observed and projected Arctic September sea-ice extent 1900-2100



Policy context and targets

Context description

In April 2009 the European Commission presented a White Paper on the framework for adaptation policies and measures to reduce the European Union's vulnerability to the impacts of climate change. The aim is to increase the resilience to climate change of health, property and the productive functions of land, inter alia by improving the management of water resources and ecosystems. More knowledge is needed on climate impact and vulnerability but a considerable amount of information and research already exists which can be shared better through a proposed Clearing House Mechanism. The White Paper stresses the need to mainstream adaptation into existing and new EU policies. A number of Member States have already taken action and several have prepared national adaptation plans. The EU is also developing actions to enhance and finance adaptation in developing countries as part of a new post-2012 global climate agreement expected in Copenhagen (Dec. 2009). For more information see:


No targets have been specified

Related policy documents

No related policy documents have been specified



Methodology for indicator calculation

Methodology for gap filling

Methodology references

No methodology references available.


Data specifications

EEA data references

  • No datasets have been specified here.

External data references

Data sources in latest figures



Methodology uncertainty

Data sets uncertainty

Rationale uncertainty

No uncertainty has been specified

Further work

Short term work

Work specified here requires to be completed within 1 year from now.

Long term work

Work specified here will require more than 1 year (from now) to be completed.

General metadata

Responsibility and ownership

EEA Contact Info

Hans-Martin Füssel


European Environment Agency (EEA)


Indicator code
CLIM 010
Version id: 1


DPSIR: Impact
Typology: Descriptive indicator (Type A - What is happening to the environment and to humans?)



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