Arctic sea ice extent is declining, and air temperatures are rising. Vegetation is changing, with tundra being replaced by shrubs. Permafrost is warming and thawing over parts of the Arctic. Some of these changes, such as the replacement of of white reflective sea ice with dark open water, are setting in motion feedbacks that contribute to even further warming. As the Arctic warms, some animal species are finding the region more hospitable, while others are seeing declines in their habitat. The Arctic region is becoming imbalanced, with ramifications for the rest of the hemisphere.
Hinzman, Larry D., Clara J. Deal, A. David McGuider, Sebastian H. Mernild, Igor V. Polyakov, and John E. Walsh. 2013. Trajectory of the Arctic as an integrated system. Ecological Applications 23(8), 1837–1868.