Polar bears (Ursus maritimus) are sentinel species for Arctic climate change. Shrinking sea ice is causing measurable welfare decline — reduced body condition, longer fasting periods, and drowning.
Polar bear welfare is deteriorating measurably as climate change reduces sea ice availability. Extended fasting periods cause progressive weight loss, muscle catabolism, and reproductive failure — pregnant females who cannot accumulate sufficient fat fail to produce viable cubs. Body condition scoring studies from Hudson Bay document a population-wide decline in condition over decades, directly correlated with earlier ice break-up. Nutritional stress in mothers reduces milk quality and cub survival. Bears swimming in open water for extended periods — sometimes over 60 km — face exhaustion and drowning risk. These are not abstract population statistics but individual welfare experiences: bears that are hungry, exhausted, and unable to meet their biological needs in a degrading environment. Climate mitigation is the only long-term solution to this welfare crisis.