40-year decline in Western Hudson Bay polar bear population nears extinction if greenhouse gas reduction is not implemented.

Climate change is threatening the Western Hudson Bay polar bear population, which has halved to about 600 bears over 40 years. If greenhouse gas emissions aren't reduced, this population may vanish by the century's end. Melting sea ice disrupts the Arctic marine ecosystem, impacting the food chain, particularly the availability of high-fat seals that polar bears rely on. Researchers warn that an increase of 1.3-1.4°C could lead to their extinction.