Polar bears hunt seals through the arctic sea ice to fatten up for the months ahead. If the ice breaks up early, they have less chance to catch enough seals for themselves and their cubs. Global warming appears to be causing arctic ice to melt and break up earlier each year, and the health of many bears seems to be declining. Another threat to bear populations is from chemical pollution. Pollutants called PCBs (polychlorinated biphenyls) get into the food chain from factory effluents and accumulate in the polar bears’ fatty tissue. At high concentrations, these chemicals have been shown to disrupt the normal development of polar bears' sexual organs leaving them sterile. This means that with no young bears being born, polar bear populations can only decline in the future.

For more information about Polar Bears see wildfacts.