Antarctica’s Thwaites Glacier, known as the Doomsday Glacier, could vanish in less than two centuries, according to U.S. and British scientists. Spanning 75 miles wide and covering 74,000 square miles, it significantly contributes to global sea level rise. Melting from Thwaites already accounts for 4% of the rise, and its collapse could add over two feet. The glacier has been shrinking since its discovery in 1940, with accelerated retreat in the past 30 years. Researchers warn that its retreat will likely speed up further, potentially sooner than current models predict.