Arctic Report Card 2010
The Arctic Report Card (www.arctic.noaa.gov/reportcard/) tracks recent environmental changes throughout the Arctic, and is updated annually. In 2010, it is clear that the Arctic is experiencing the impacts of a prolonged and amplified warming trend, highlighted with many record-setting events. Not surprisingly, the impact of this warming is most evident in the dramatic losses that have been observed in the ice covers that define the region. Since the loss of these ice covers serves to further feed the warming trend, the expectation is that warming will continue. This makes it increasingly unlikely (at least for the foreseeable future) that the Arctic will return to conditions that were considered normal in the later part of the 20th century. Instead, it is very likely that Arctic climate warming will continue and we will continue to see records set in years to come.
Highlights for 2010:
In 2010, there was continued widespread and, in some cases, dramatic effects of a warming Arctic, where deviations from the average air temperature are amplified by a factor of two or more in the Arctic relative to lower latitudes. As the air temperature increases, ice (which presents a bright, white, highly reflective surface) melts, revealing darker ocean and land surfaces that absorb more solar energy during a summer season when the sun never sets. This causes more heating, which causes more melting, continuing a cycle that contributes to Arctic amplification. In 2010, there were some dramatic examples of the effects of this cycle.
Record warm air temperatures were observed over Greenland in 2010. This included the warmest year on record for Greenland's capital, Nuuk, in at least 138 years. The duration of the melt period on Greenland’s inland ice sheet was exceptional, being 1 month longer than the average over the past 30 years, and led to an extended period of amplified summer melt. All of the additional melt water very likely contributing to a faster rate of crevasse widening. Glacier loss along the Greenland margins was also exceptional in 2010, with the largest single glacier area loss (110 square miles, at Petermann glacier) equivalent to an area four times that of Manhattan Island. There is now no doubt that Greenland ice losses have not just increased above past decades, but have accelerated. The implication is that sea level rise projections will again need to be revised upward.
The record warm air temperature in 2010 extended over the Canadian Arctic. Coupled with a longer melt season, these conditions caused a continued increase in the rate of ice mass loss from other smaller glaciers and ice caps in the Canadian Arctic.
The combination of warm spring air temperatures and low winter snow accumulation led to a new record minimum in springtime snow cover duration over the Arctic. The warming air temperatures also played a major role in the observed increases in permafrost temperatures around the Arctic rim, the increase in river discharge to the Arctic Ocean, and the increase in the greenness of Arctic vegetation.
The September 2010 Arctic sea ice extent was the third smallest of the past 30 years. This continues an ongoing trend, with the four smallest September ice extents having occurred in the past four years. Eight of the ten lowest summer minimums have occurred in the last decade. The amount of older, thicker multiyear ice was the third smallest ever, and there was a notable loss of multiyear in the Beaufort Sea, north of Alaska. Looking at the geographical distribution of ice extent we see that both the Northern Sea Route and the Northwest Passage were ice-free in September.
The changes in the extent and duration of the sea ice cover are also strongly linked to changes in the Arctic Ocean surface temperatures. Observations show that the distribution of summer surface temperatures reflects the speed and location of the retreat of the summer sea ice cover.
It is also apparent that changes in sea ice conditions and, more broadly, changes in the physical environment are impacting local populations and ecosystems. The biological essays in the 2010 Arctic Report Card highlight the inherently fluctuating nature of Arctic ecosystems. For instance, Barents Sea harvested fish stocks continue to fluctuate, and there are indications that these changes may be linked to sea temperatures and the associated fluctuations in sea ice cover. With the expectation of continued warming air temperatures, Arctic species that have adapted to the Arctic environments are expected to be displaced by the encroachment of more southerly (sub-Arctic) species and ecosystems. Gaining a better understanding of how the Arctic's living resources are responding to these environmental changes is essential to develop effective conservation and adaptation strategies.
One final highlight from the 2010 Arctic Report Card that illustrates the impact of Arctic change on populations, is the link that scientists have identified, and are still trying to explain, between changes in the Arctic and severe cold weather in December 2009 and February 2010 in eastern North America, northern Europe and eastern Asia.
While we see somewhat direct relationships between warming and ice cover melt, it is more difficult, due to the complex nature of ecosystems, to predict and understand how these biological systems are and will respond to this amplified warming trend. This final point helps emphasize the fact that the Arctic is an inherently complicated system.
The Arctic Report Card reflects the work of an international team of 69 researchers and is based upon 174 scientific references. It is supported by the international Arctic Council, and The Circumpolar Biodiversity Monitoring Program (CBMP), the cornerstone program of the Arctic Council’s Conservation of Arctic Flora and Fauna (CAFF) Working Group, provides leadership on the biological elements of the report card. Support for the Arctic Report Card is provided by the NOAA Climate Program Office through the Arctic Research Program.