evidence: The Arctic is warming three times as fast and the global average. This is mainly because melting of snow and ice exposes a darker surface and increases the amount of solar energy absorbed in these areas (albedo effect?). This significant regional warming leads to continued loss of sea ice, melting of glaciers and of the Greenland ice cap. [...] The degree of warming seen in the Arctic since 1980 is twice that in the rest of the world. Temperatures in most parts of the Arctic have increased substantially in the past few decades, particularly in winter. The winter increase in Alaska and western Canada has been around 3–4°C over the past half century. Meteorological stations in the Norwegian High Arctic have also noted increasing temperatures. In Longyearbyen, the yearly average temperature increased by about 0.25°C per decade from when measurements started in 1912 through 2011, a slightly larger increase than for the Arctic as a whole over the same time period. Examination of available knowledge and evidence reveals that the years 2005–2011 have been the warmest ever recorded in the Arctic. In recent years, the warming trend has been strongest in fall and spring.