Linking Arctic variability and change with extreme winter weather in the United States

Cold weather disruptions Despite the rapid warming that is the cardinal signature of global climate change, especially in the Arctic, where temperatures are rising much more than elsewhere in the world, the United States and other regions of the Northern Hemisphere have experienced a conspicuous and increasingly frequent number of episodes of extremely cold winter weather over the past four decades. Cohen et al . combined observations and models to demonstrate that Arctic change is likely an important cause of a chain of processes involving what they call a stratospheric polar vortex disruption, which ultimately results in periods of extreme cold in northern midlatitudes (see the Perspective by Coumou). —HJS