The Arctic and Antarctic: two faces of climate change

Although both the Arctic and Antarctic are subject to a similar annual cycle of solar radiation and the same increasing greenhouse gas concentrations, over the previous two decades the two regions have experienced dramatically different changes in sea ice extent, temperature, and other climatic indicators. While these differing responses suggest a paradox, they are largely consistent with known climate dynamics. This conclusion was drawn by scientists participating in the Second Workshop on Recent High Latitude Climate Change, in Seattle, Wash., in October 2007, against the dramatic backdrop of major Arctic sea ice reductions 1 month earlier [World Climate Research Programme, 2007].