Arctic sea ice extent and volume




Sea ice melt is the most apparent global indicator of climate change, and is especially relevant for the circumpolar North. As the Earth’s energy balance alters, most of the energy goes into the oceans and the remainder into ice, soil and the atmosphere. The Arctic Ocean is a confluence of these three elements.

Arctic sea ice is melting, indicated by changes in the extent of ice across Arctic and northern oceans as well as changes in the thickness (volume) of that ice. Less and less ice is surviving from one year to the next, and the ice that is lasting for more than one season is thinning significantly.

The net result, if this trend continues, is that summer sea ice will melt out in the Arctic within the next decade or decades. This has wide ranging implications for the Arctic and the globe, including sea level rise, increased coastal erosion, damage to human infrastructure and negative impacts on species that depend on sea ice.


Ice on the Beaufort Sea.



What is happening?

  • Arctic sea ice is melting, reducing both the area that it covers every year and its overall volume.
  • Sea ice melt appears to be accelerating, with most of the melt occurring in the past decade.
  • Figure 1 shows the annual extent (area) in September (in millions of square kilometers) of Arctic sea ice with at least 15 per cent ice concentration.


Figure 1: Arctic September Sea Ice Extent


  • September sea ice loss averages 90,000 km2 per year, although there is significant variability from one year to the next.
  • Figure 2 shows the annual Arctic September sea ice volume (in thousands of square kilometers).
  • Approximately 300 km3 of sea ice volume is lost per year. Existing sea ice is becoming thinner.


Figure 2: Arctic September Sea Ice Volume



Taking action

The Government of Yukon partnered with the Northern Climate ExChange at Yukon College on developing a Yukon Climate Change Indicators and Key Findings report. This cross-sector, structured, evidence-based assessment of Yukon climate change knowledge synthesizes our current understanding, providing researchers, decision makers and the general public with an objective overview of the climate system and any potential changes. Sea ice extent and volume are two indicators presented in this report.

Reducing GHG emissions in Yukon will help to reduce the long-term negative impacts of the trends presented in this indicator.

Beaufort Sea, ice along Herschel Island shoreline.


Data quality

  • Since sea ice has such a wide annual variation in distribution, it is typical to compare data from a particular month over time. Most often September is used as sea ice reaches its minimum extent each year in September.
  • The National Snow and Ice Data Centre gather satellite data to make calculations for sea ice extent. You can find this data online.
  • For sea ice volume, data is made available by the University of Washington Pan-Arctic Ice-Ocean Modeling and Assimilation System (PIOMAS) online.



National Snow and Ice Data Center. 2015. Sea Ice Index, Version 1. University of Colorado, Boulder, Colorado, U.S.A. Available from: http://nsidc.org/data/g02135.html

Polar Science Center, Applied Physics Laboratory. 1979-2016. PIOMAS Daily Ice Volume Data, 1979-present [cited 2016, Mar 3]. University of Washington, Seattle, Washington, U.S.A. Available from:

Streicker, J. 2016. Yukon Climate Change Indicators and Key Findings 2015. Northern Climate ExChange, Yukon Research Centre, Yukon College, Whitehorse, Yukon, Canada. Available from: https://www.yukoncollege.yk.ca/research/abstracts/indicators.