How has a rise on global temperature impacted the life of the polar bear? a rise in temperatures has disrupted the arctic food chain common to polar bears. key to maintaining a healthy weight and insulative fat layer is a diet of seals. the us geological survey suggest that if such trends continue, two-thirds of the world's arctic ice could disappear by 2050. the accumulation of greenhouse gases in the earth's atmosphere has been substantially increased by the combustion of fossil fuels. scientists predict that malnourishment among the bears resulting in smaller litter sizes will result in their extinction in several decades. as a result of melting sea ice, there should be more vegetation on-shore for the polar bears to eat.