Global temperatures have increased 1.4°F since 1880, with the hottest decades being the last two of the 20th century. The Arctic is warming twice as fast as the rest of the world, potentially becoming ice-free in summer by 2040. Glaciers and snowfields are melting rapidly, with Glacier National Park now having only 27 glaciers compared to 150 in 1910. Coral reefs suffered severe bleaching in 1998 due to rising ocean temperatures, and extreme weather events are also increasing due to climate change.