Climate change affects polar bears in many negative ways, including decreased access to food, lower survival rates for cubs, damages to polar bear dens and a decrease in overall polar bear population. Many scientists point to climate change as the largest threat to polar bears.
Increasing temperatures due to global warming create lower arctic sea ice levels, which wreak havoc on polar bears’ ecosystems. Lack of sea ice makes hunting more difficult, leading to drops in cub survival rates and increases in cannibalism among polar bears. Studies of polar bear populations have also revealed declines in weight and skull size among adult male polar bears, which is likely due to food shortages.
Changes in habitats due to global warming have also affected polar bears negatively. Some polar bears are stranded on land during long summers that prevent sea ice from forming and packing. Declines in permafrost levels can also lead to forest fires that destroy polar bear dens during the summer. Warmer weather can also lead to increases in rainfall, which can damage polar bear dens and cause them to collapse.
Global warming has also led to an increase in drowning deaths among polar bears. Changes in arctic ice levels create too much open water, which can drown bears when they attempt to swim too far.