Scientific research into the relationships between sea ice loss, body condition, reproductive success, and survival in polar bears provides the evidence base for their climate-driven welfare crisis.
The welfare science of polar bears under climate change reveals how environmental change creates cascading individual and population welfare effects. Declining body condition reduces the energetic reserves needed for denning, cub production, and winter fasting, creating a cascade from environmental deterioration to reproductive failure to population decline. Individual animals experiencing the longest fasting periods suffer the greatest welfare harm from hunger, but also face increased risk of dangerous encounters with humans as they move into coastal communities seeking food. The non-linear nature of projected decline suggests that welfare impacts will intensify rapidly once sea ice loss crosses critical thresholds, making the current window for effective climate intervention increasingly urgent.