Snow, Water, Ice and Permafrost in the Arctic Summary for Policy-makers This Summary for Policymakers presents key findings and implications of the second SWIPA assessment, conducted from 2010 to 2016 and published in 2017. More than 90 scientists contributed to the assessment, which was peer-reviewed by 28 experts in a rigorous quality control process. More details on the SWIPA process and findings are available in the full SWIPA report, available at www.amap.no/swipa. The Snow, Water, Ice and Permafrost in the Arctic (SWIPA) assessment is a periodic update to the Arctic Climate Impact Assessment, published in 2005 by the Arctic Monitoring and Assessment Programme (AMAP), the Conservation of Arctic Flora and Fauna (CAFF), and the International Arctic Science Committee (IASC). SWIPA focuses on changes to the Arctic cryosphere (the portion of Arctic land and water that is seasonally or perennially frozen), and the implications of those changes. The first SWIPA assessment was conducted between 2008 and 2010, and was published in 2011. About the Arctic Council The Arctic Council is the leading intergovernmental forum promoting cooperation, coordination, and interaction among the Arctic States, Arctic indigenous peoples, and other Arctic inhabitants on common Arctic issues, in particular on issues of environmental protection and sustainable development in the Arctic. Established in 1996, the Arctic Council is composed of eight Member States (Canada, the Kingdom of Denmark, Finland, Iceland, Norway, the Russian Federation, Sweden, and the United States). It also includes six organizations representing Arctic indigenous peoples: the Aleut International Association, the Arctic Athabaskan Council, Gwich’in Council International, the Inuit Circumpolar Council, the Russian Association of Indigenous Peoples of the North, and the Saami Council. About AMAP AMAP, established in 1991 under the eight-country Arctic Environmental Protection Strategy, monitors and assesses the status of the Arctic region with respect to pollution and climate change. AMAP produces science- based, policy-relevant assessments and public outreach products to inform policy and decision-making processes. Since 1996, AMAP has served as one of the Arctic Council’s six working groups. 2 Photo: Søren Rysgaard Photo: Søren Key Findings Key findings of the SWIPA 2017 assessment include: The Arctic’s climate is shifting 1 to a new state Rising concentrations of greenhouse gases are driving widespread changes in the Arctic’s sensitive climate, hydrological, and ecological systems. Since 2011, downward trends have continued in sea ice thickness and extent, land ice volume, and spring snow cover extent and duration, while near-surface permafrost has continued to warm. With each additional year of data, it becomes increasingly clear that the Arctic as we know it is being replaced by a warmer, wetter, and more variable environment. This transformation has profound implications for people, resources, and ecosystems worldwide. While SWIPA 2017 includes many important new findings, summarized below, three points in particular deserve special emphasis: • The Arctic Ocean could be largely free of sea ice in summer AMAP Assessment Area as early as the late 2030s, only two decades from now. • The recent recognition of additional melt processes affecting Arctic and Antarctic glaciers, ice caps, and Climate change in the Arctic ice sheets suggests that low-end projections of global 2 has continued at a rapid pace sea-level rise made by the Intergovernmental Panel on Climate Change (IPCC) are underestimated. • Arctic temperatures are rising faster than the global average. The Arctic was warmer from 2011 to 2015 than • Changes in the Arctic may be affecting weather at any time since instrumental records began in around in mid-latitudes, even influencing the Southeast 1900, and has been warming more than twice as rapidly Asian monsoon. as the world as a whole for the past 50 years. January 2016 in the Arctic was 5°C warmer than the 1981–2010 average for the region, a full 2°C higher than the previous record set in 2008, and monthly mean temperatures in October through December 2016 were 6°C higher than THE ROLE OF ARCTIC average for these months. Sea temperatures are also GLACIERS AND ICE CAPS IN increasing, both near the surface and in deeper water. GLOBAL SEA-LEVEL RISE • The frequency of some extreme events is changing. Recent observations include a widespread decline in Scientific advances since 2011 show that while periods of extreme cold during both winter and summer, Arctic glaciers and ice caps represent only a quarter of the world’s land ice area, meltwater and increases in extreme warm periods in some areas, from these sources accounts for 35% of current such as northern Alaska and northeastern Russia in global sea-level rise. autumn and spring. 3 Sea ice is becoming more mobile as its extent and TRADITIONAL AND LOCAL thickness decrease, increasing ice-related hazards. KNOWLEDGE More open water occurs in all months of the year compared with observations reported in 2011. The SWIPA scientifi c assessment is based primarily on peer-reviewed observations, methods, and • The area and duration of snow cover are decreasing. studies, which in many cases include contributions Snow cover has continued to decline in the Arctic, with from traditional and local knowledge. However it is recognized that this approach does not necessarily its annual duration decreasing by 2–4 days per decade. capture all relevant knowledge held by Indigenous In recent years, June snow area in the North American and local communities. and Eurasian Arctic has typically been about 50% below values observed before 2000. • Permafrost warming continues. Near-surface • The decline in sea ice continues, with variation from permafrost in the High Arctic and other very cold areas year to year Sea ice thickness in the central Arctic has warmed by more than 0.5°C since 2007–2009, Ocean declined by 65% over the period 1975–2012. and the layer of the ground that thaws in summer has Sea ice extent has varied widely in recent years, but deepened in most areas where permafrost is monitored. continues a long-term downward trend. A record low minimum sea ice extent occurred in 2012 and a record • The loss of land-based ice has accelerated in recent low maximum sea ice extent occurred in 2016. decades. Since at least 1972 the Arctic has been the dominant source of global sea-level rise. Seventy percent Older ice that has survived multiple summers is rapidly of the Arctic’s contribution to sea-level rise comes from disappearing; most sea ice in the Arctic is now ‘fi rst year’ Greenland, which on average lost 375 gigatons of ice ice that grows in the autumn and winter but melts during per year—equivalent to a block of ice measuring 7.5 the spring and summer. kilometers or 4.6 miles on all sides—from 2011 to 2014. Except for the coldest northern regions of the Arctic This is close to twice the rate over the period 2003–2008. Ocean, the average number of days with sea ice cover • Freshwater storage in the Arctic Ocean has in the Arctic declined at a rate of 10–20 days per decade increased. Compared with the 1980–2000 average, the over the period 1979–2013, with some areas seeing volume of freshwater in the upper layer of the Arctic much larger declines. Warm winds during the autumn Ocean has increased by 8,000 cubic kilometers, or more of 2016 substantially delayed the formation of sea ice. than 11%. This volume equals the combined annual Sea level contribution, mm/yr 1.2 1.0 Thermal expansion Antarctic land ice 0.8 Greenland ice sheet Canadian Arctic glaciers 0.6 During the period 2004– Russian Arctic glaciers 2010, melting Arctic land ice accounted for more than U.S. Arctic (Alaskan) glaciers 1/3 of global sea-level rise, 0.4 while thermal expansion Greenland glaciers caused by warming water Scandinavian glaciers contributed another 1/3 0.2 and contributions from Other glaciers Antarctica, other glaciers and changes in terrestrial storage Terrestrial storage 0 contributed less than 1/3. 4 discharge of the Amazon and Ganges rivers, and could— • The Arctic Ocean may be ice-free sooner than if it escapes the confines of the Arctic Ocean—affect expected. Extrapolations of recent observed data circulation in the Nordic Seas and the North Atlantic. suggest a largely ice-free summer ocean by the late 2030s, which is earlier than projected by most climate . The decline in sea ice • Ecosystems are changing models. Natural variability and model limitations make thickness and extent, along with changes in the timing precise predictions impossible. of ice melt, are affecting marine ecosystems and biodiversity; changing the ranges of Arctic species; • Declines in snow and permafrost will continue. increasing the occurrence of algal blooms; leading to The duration of snow cover is projected to decrease by an changes in diet among marine mammals; and altering additional 10–20% from current levels over most of the predator-prey relationships, habitat uses, and migration Arctic by mid-century under a high emissions scenario, patterns. Terrestrial ecosystems are feeling the effects of and the area of near-surface permafrost is projected to changes in precipitation, snow cover, and the frequency decrease by around 35% under the same scenario. or severity of wildfires. The occurrence of rain-on-snow and winter thaw/refreezing events affects grazing animals • The melting of land-based ice will contribute . If increases in such as caribou, reindeer, and muskox by creating an significantly to sea-level rise greenhouse gas concentrations continue at current rates, ice barrier over lichens and mosses. While many tundra the melting of Arctic land-based ice would contribute an regions have become greener over the past 30 years, estimated 25 centimeters to sea-level rise between 2006 reflecting an increase in plant growth and productivity, and 2100.