人類挖掘化石燃料、發展等破壞，導致全球暖化，過去25年北極四成的冰層消失，北極熊不能再以原本的方式捕獵，有些嘗試到岸上覓食。因嚴重缺乏食物，近來更出現捕食同類的情況。研究員拍到雄性北極熊追捕一對母子，最後把幼熊吃掉；另外亦有發現雌熊把自己孩子吃掉。

fossil fuel extraction, human developments and activities are causing climate change; 40% of ice levels in the Arctic has disappeared in the past 25 years. Polar bears lost their habitats and could no longer hunt like they used to, some moved to the land, and recently researchers found they begin to feed on their own species. A male polar bear was filmed attacking female and cub, and females feeding on their own cubs.

https://interestingengineering.com/polar-bears-forced-into-cannibalism-due-to-climate-change-and-fossil-fuels

https://www.nownews.com/news/20200301/3963008/