Due to warming air temperatures, ice-floe breakup in western Hudson Bay is currently occurring three weeks earlier than it did 30 years ago, reducing the duration of the polar bear feeding season. The body condition of polar bears has declined during this period; the average weight of lone (and likely pregnant) female polar bears was approximately in 1980 and in 2004. Between 1987 and 2004, the Western Hudson Bay population declined by 22%, although the population was listed as "stable" as of 2017. As the climate change melts sea ice, the U.S. Geological Survey projects that two-thirds of polar bears will disappear by 2050.