Arctic Report Card 2011: Tracking recent environmental changes Atmosphere Summary Temperature and Clouds Carbon Dioxide (CO2) and Methane (CH4) Ozone and UV Radiation Sea Ice and Ocean Summary Ocean The Extent and Controls on Ocean Acidification in the Western Arctic Ocean and Adjacent Continental Shelf Seas Marine Ecosystems Summary Arctic Ocean Primary Productivity Biodiversity - Status and Trends of Polar Bears Biodiversity - Cetaceans and Pinnipeds (Whales and Seals) Marine Ecology: Biological Responses to Changing Sea Ice and Hydrographic Conditions in the Pacific Arctic Region Terrestrial Ecosystems Summary Caribou and Reindeer (Rangifer) Hydrology and Terrestrial Cryosphere Summary Glaciers and Ice Caps (outside Greenland) Greenland Ice Sheet Permafrost Lake Ice River Discharge River Biogeochemistry

The Arctic Report Card (www.arctic.noaa.gov/reportcard/) considers a wide range of environmental observations throughout the Arctic, and is updated annually. A major conclusion of the 2011 Report is that there are now a sufficient number of years of data to indicate a shift in the Arctic Ocean system since 2006. This shifted is characterized by the persistent decline in the thickness and summer extent of the sea ice cover, and a warmer, fresher upper ocean. As a result of increased open water area, biological productivity at the base of the marine food chain has increased and sea ice-dependent marine mammals continue to lose habitat. Increases in the greenness of tundra vegetation and permafrost temperatures are linked to warmer land temperatures in coastal regions, often adjacent to the areas of greatest sea ice retreat. A second key point in the 2011 Report is the repeated occurrence of 2010 Arctic winter wind patterns that mark a departure from the norm. These changes resulted in higher than normal temperatures in the Arctic, with record ice sheet mass loss, record low late spring snow cover in Eurasia, shorter lake ice duration, and unusually lower temperatures and snow storms in some low latitude regions. A potential indicator of recent atmospheric changes was record low ozone concentrations in March 2011. The 2011 Report Card shows that record-setting changes are occurring throughout the Arctic environmental system. Given the projection of continued global warming, it is very likely that major Arctic changes will continue in years to come, with increasing climatic, biological and social impacts.