Polar bears are facing existential threat from Arctic sea ice loss driven by climate change, with declining body condition, reproductive failure, and starvation becoming increasingly common.
Polar bears experiencing prolonged fasting due to sea ice loss suffer progressive starvation. Females with cubs face the sharpest welfare impacts — nursing while fasting draws down body reserves rapidly, and malnourished mothers produce less nutritious milk for cubs that are already nutritionally stressed. Bears with no sea ice platform cannot hunt efficiently and must swim long distances between ice floes, causing exhaustion. Cubs of swimming mothers risk drowning. The welfare trajectory for polar bears under continued climate change is one of gradually increasing chronic suffering across the entire population.