According to a scientific study published in 'Nature' in July 2020, polar bears could become extinct by 2100. Their population is expected to decrease along with global warming and the reduction of sea ice. The researchers produced a precise chronological estimation starting from the physiology of the species (weight, fat, energy expenditure, etc.) and estimating its possible fasting duration before its survival and reproduction are threatened. The results obtained were then put in relation with the anticipated number of days when the sea ice will fail by including two possible scenarios based on a substantially constant or slightly reduced emission of greenhouse gases.