This study demonstrates that climate-driven changes to snow and ice (the cryosphere) in Western Finnmark, Norway, are actively undermining the viability of traditional Sámi reindeer herding. By integrating Sámi Indigenous knowledge with scientific observation, the research highlights how these environmental shifts disrupt a practice central to Sámi culture and economy. For the approximately 1,500 Sámi herders in Western Finnmark, predictable cryospheric conditions are a necessity for managing their 80,000 reindeer, as their nomadic livelihood is built around seasonal migrations where frozen rivers and lakes provide migration corridors and consistent snow cover is essential for accessing lichen. Drawing on the direct observations of Sámi herders, the study identifies critical environmental changes that are already having a significant impact, such as unreliable ice formation in autumn that makes traditional migration routes dangerous or impassable. Furthermore, poor snow quality from fluctuating freeze-thaw cycles creates dense, icy snow layers that prevent reindeer from reaching their food. These challenges are worsened by increasing land-use fragmentation. The paper argues that Sámi Indigenous knowledge is an essential dataset for understanding these real-world impacts and concludes there is an urgent need to formally integrate this local expertise into scientific research and policy development to create effective adaptation strategies and support the long-term sustainability of Sámi reindeer herding in a rapid changing Arctic.
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