The loss sea ice habitat from climate change is the biggest threat to the survival pf polar bears. Other reasons include human-polar bear conflict, toxic pollution, oil spills and potential hunting of some subpopulations.
Polar Bear-Human Conflicts
As the sea ice of the Arctic thins and disperses, increasing number of polar bears spend longer periods in along the Arctic coastlines. Here their powerful sense of smell attracts them to human communities. Scent leading to garbage, stored food, dog teams, and animal carcasses bring them into greater conflict with people residing in the Arctic.
As apex predators, polar bears pose a significant threat to human life and property. In recent years the attacks on humans, who come within the polar bear’s range, continue to rise.
Effects of Climate Change
Due to climate change the Arctic is heating up twice as fast as anywhere in the world, melting the sea ice cover by 14% per decade. Comparing the data recorded between 1981-2010, we have lost about 770,000 square miles.
Polar bears rely on sea ice as their hunting ground and to rest, breed, and store energy for the summer and sutumn, when food can be scarce. The bears health decline as they go longer periods without food. Bears that come ashore, after the ice breaks up, are roughly 22 pounds lighter and in poorer condition. They also must travel long distances to stay with the rapidly receding ice.
Polar bears suffering from malnutrition can face extreme starvation -especially females with cubs. Scientists have found the main cause of death for cubs to be either lack of food or lack of fat on nursing mothers.
As summer ice retreats, a new ocean is emerging, which allows more opportunities for industrial development at sea, and on large parcels of land. Offshore petroleum installations and operations in the Arctic are expected to increase in number. This results in destruction of habitat, poisoning of the bears when they ingest oil and contaminated prey which causes disturbance in the food web. As traffic by oil tankers and cargo ships in Arctic waters increases, so do the oil spills and human disturbance to their habitat.