I’ve always said that one must consider how apex predators generally end up. Anything that impairs their ability to hunt is a death sentence by starvation. If a study could be done, I believe it would conclude that the majority of polar bears die by starvation, usually caused by an age related infirmity or an injury.
Actually, the photo stands in opposition to the NatGeo thesis: Extrapolating from one bear, as they did, we can conclude that climate change allows polar bears to live long enough to die of starvation.