Adaptation Actions for a Changing Arctic: Perspectives from the Barents Area

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4 . Physical and socio-economic environment

Coordinating Lead Authors : Rasmus Benestad, Vladimir Ivanov, Peter Arbo, Glen Peters Lead Authors : Maria Ananicheva, Andreas Dobler, Ralf Döscher, Igor Ezau, Randi Ingvaldsen, Ketil Isaksen, Christian Jaedicke, Zbigniew Klimont, Torben Koenigk, Meri Korhonen, Kaarle Kupiainen, Anna Luomaranta, Arne Melsom, Geir Moholdt, Jan Even Nilsen, Gunnar Noer, Kajsa Parding, Ville-Veikko Paunu, Anette Rinke, Anne Britt Sandø, Dagrun Vikhamar Schuler, Igor Shkolnik, Morten Skogen, Michael Tjernstrøm, Ari Venäläinen, Timo Vihma

4.1 Introduction This chapter provides a quantitative (where possible) description of what will shape the future Barents area in terms of its regional climate, and its physical and socio-economic environment.This includes a detailed description of these changes with respect to specific components of the climate system: the atmosphere (Section 4.2), ocean (Section 4.3) and land (Section 4.4), as well as socio-economic conditions (Section 4.5). This overview is based on scientific knowledge frommultiple sources, including modelling studies and observations (Box 4.1). The main Key messages •• The Barents Sea plays an integral role in the atmospheric and oceanic circulations, water masses and marine ecosystems of the Arctic. Many drivers and impacts are interconnected and feedbacks are a source of considerable uncertainty. The Arctic is warming faster than the global average, and projections suggest an increase of 3–10°C in winter between 2015 and 2080 for the RCP4.5 scenario. Winter warming under RCP8.5 may be up to 20°C. More precipitation is expected to fall as rain in the future,amplified by the sea-ice retreat and increasing the probability of rain-on-snow events. Natural hazards include synoptic storms, avalanches, and extreme wave heights, but current projections are unable to provide robust indications of change other than a poleward shift in storm tracks.The risk of polar lows is projected to decrease in future as conditions become less favorable for their occurrence. •• The Barents Sea is expected to become the first Arctic region that is ice-free all year round. The business-as- usual emissions scenario (RCP8.5) implies a 94% reduction in September sea-ice extent. Sea ice influences the connection between ocean and the atmosphere, planetary energy flow, weather phenomena, and marine life, and so a decrease in its extent and volume could have profound effects on the future Barents area. Icebergs represent a major hazard to marine activity in the Barents Sea and the number fluctuates from year to year. There is some indication of increased numbers extending further south associated with warming, but the long-term statistics on icebergs in the Barents Sea are incomplete. •• Major changes are expected in snow cover and permafrost properties within the Barents area. Snow cover extent and snow season duration have decreased most at high latitudes (60–70°N), and the decline in snow cover in Eurasia over the

emphasis of this chapter is on those drivers and trends that originate outside the region. Later chapters address potential interactions and the consequences of these changes.The chapter concludes with a discussion that draws together the major findings reported here (Section 4.6). Ongoing and future environmental change within Barents area will have significant for consequences for the people living and working there, as well as for the many sectors and activities within the region. This chapter presents a plausible future picture,based on past observations as well as downscaled results from global climate models (GCMs) and recent assessments •• The Barents area is strongly affected by global social, economic, political and cultural changes, which interact with climate change and can make people and societies more or less vulnerable and able to adapt. The main non- climate drivers at a global scale include population growth, urbanization, economic growth, technology development, demand for natural resources and energy, and the level of international cooperation. The Barents area will be influenced by external megatrends through migration, trade, investments, government policies and laws, but the implications for the different subregions will depend on their natural and human resources, their institutional characteristics, and the policies adopted. period 2007–2014 has accelerated compared to earlier periods. Themelt onset date in spring advanced by about 1–2 weeks in the 1979–2012 period,and the duration of snow cover in 2050 is projected to be about 30-40% shorter than in 2011. There has been an observed change in the timing of spring flood associated with changes in the timing of snowmelt, and the dates for ice formation onwaterways has shifted to later in the season.Annual maximumsnowdepth has increased in colder regions such as Russia but has decreased inwarmer locations, and future projections suggest a continued increase in some places. Observations suggest an increase in hard snow layers from 1961 to 2009, with harder snow in early winter,‘wetter’ snowduring spring,and futurewarmingmay bringmore rain- on-snow events. Black carbon enhances snow melt through reduced albedo and also has negative impacts on human health. However, there is potential for reducing black carbon emissions by up to three-quarters by 2030.The permafrost is thawing, and the projected warming and increases in snow thickness will result in near-surface permafrost degradation over large geographic areas.