The National Oceanic and Atmospheric Administration (NOAA) has just published its 2010 update on the Arctic environment. This report was produced in collaboration with scientists from the United States, Canada, Russia, and European Union. The bottom line in this report can be summarized in a single sentence:
Return to previous Arctic conditions is unlikely.
Warming of the atmosphere and sea water in the northern hemisphere are expected to produce long-term changes in the polar region, including the loss of summer sea ice, depletion of Greenland glacial ice, permafrost melt, and stress on many animal populations. Scientists first raised the possibility of an Arctic "death spiral" several years ago, which was dismissed as a passing fantasy by the ethically-challenged, half-term governor of Alaska. The possibility of an Arctic "death spiral" now looks highly likely.
For those with video access, NOAA has created a 3-minute summary of the Arctic Report Card.
The report focuses on 6 aspects of the Arctic environment: atmosphere, sea ice, ocean, land, Greenland, and biology.
Atmosphere:
The report card focuses on two features of interest - continued warming of arctic air and shifts in weather patterns. Higher atmospheric temperatures in late summer and fall due to the loss of sea ice is beginning to affect circulation patterns in the Arctic and lower latitudes. High pressure conditions over the Arctic during winter months increases the potential to disrupt the normal west to east jetstream, allowing colder air to be pushed further south. During the previous winter, high pressure over a warm Arctic allowed moderately colder air to filter south in December and February, helping to create the massive snowstorms that fossil fool James Inhofe claimed was proof that climate change is not occurring. These warm Arctic - colder south anomalies have been rare in the past, but are expected to become more frequent with climate change.
While individual weather extreme events cannot be directly linked to larger scale climate changes, recent data analysis and modeling suggest a link between loss of sea ice and a shift to an increased impact from the Arctic on mid-latitude climate (Francis et al. 2009; Honda et al. 2009). Models suggest that loss of sea ice in fall favors higher geopotential heights over the Arctic. With future loss of sea ice, such conditions as winter 2009-2010 could happen more often. Thus we have a potential climate change paradox. Rather than a general warming everywhere, the loss of sea ice and a warmer Arctic can increase the impact of the Arctic on lower latitudes, bringing colder weather to southern locations.
Arctic Report Card, page 13
Sea Ice:
Sea ice loss has been more pronounced over the past three years. The trend indicates more extensive retreat of sea ice during summer months and less recovery during winter months.
Both winter and summer ice extent exhibit a negative trend, with values of - 2.7% per decade for March and - 11.6% per decade for September over the period 1979-2010.
Arctic Report Card, page 16
Scientists have identified six climate models that have best captured recent changes in sea ice. Extrapolations from these models suggests that a summer ice free Arctic is likely to be seen in approximately 30 years. By the time summer sea ice disappears, sea ice at the end of winter is likely to be less than 2 meters thick.
Ocean:
Trends in water temperature and salinity vary across the Arctic region. Most of temperature anomalies are occurring on the Eurasian region of the Arctic. Salinity across the entire Arctic region is much lower than observed in the 1970s. Freshwater runoff in recent years has been greater in the Canadian basin. However, the most remarkable change was evidence of destructive acidification in some areas of the Arctic Ocean for the first time.
An interesting change in ocean geochemistry was observed in the Canada Basin in 2008 and 2009. The input of sea ice meltwater, in combination with CO2 uptake and global ocean acidification, caused the surface waters of the Canada Basin to become corrosive to calcifying organisms in the upper layer in 2008 (Yamamoto-Kawai et al. 2009).
Arctic Report Card, page 24
Land:
Increasing temperatures, decreasing snow cover, and thawing permafrost have led to large changes in vegetation. High Arctic regions of Canada, Alaska, and Greenland have experienced the most dramatic increases in greening, with increases of up to 15% since the early 1980s.
The changes in the tundra plant communities are most likely in response to the increase in air temperature over the past 35 years of between 0.6-1.0°C/decade, with the strongest increases seen in the winter temperatures. The increases in biomass also correspond with longer growing seasons, with extensions into the late summer, and with deeper active layers (depth of summer soil thawing).
Arctic Report Card, page 29
These changes in tundra vegetation are accompanied by increases in greenhouse gas emissions from permafrost thawing and fires. Tundra fires have been increasing since 2007 due to warmer summer temperatures.
Snow cover is expected to increase in some Arctic areas (such as the Canadian basin) and decrease in others (Siberia). However, the seasonal duration of snow cover is decreasing across the Arctic with earlier Spring melting. Snow cover in sub-Arctic regions appears to be decreasing rapidly. Glacier melt has also increased in Canada and Iceland.
Greenland:
The loss of Greenland glacial mass has been dramatic in recent years, particularly in the western region. The most dramatic event came in August of 2010 when a chunk of the Petermann Glacier the size of Manhattan broke off.
Picture source: NASA
The loss of Greenland glacial mass has been accelerating during the past decade.
The rate of area loss in marine-terminating glaciers this year (419 km2) was 3.4 times that of the previous 8 years, when regular observations are available. There is now clear evidence that the ice area loss rate of the past decade (averaging 120 km2/year) is greater than loss rates pre-2000.
Arctic Report Card, page 54
The warming of Greenland is readily apparent to long-time residents.
A long-term resident of Greenland wrote on 4 February, 2010: "we don´t have snow, we don´t have the cold" ... "This weather this year is really different, in 30 years that I live in Ilulissat [69.0°N along Greenland's west coast], that is the first year in this conditions. We have lot of dog sledding tourists, but we cannot do the tour, too much ice on the hills and dangerous to drive by sled." ... "no snow at all". Later, the same source remarked of "10-12 days of" continuous "heat wave" like weather, in June, with "a lot of blue skies".
Arctic Report Card, page 61
Biology:
Climate change has produced winners and losers. Among the winners, some whale species have increased in number, including the bowhead. Among the big losers are the wild caribou and reindeer populations. Perhaps the only good news is that decline in caribou and reindeer populations appear to be slowing down and may be leveling off. However, there is a great deal of uncertainty because there has been too little systematic study of marine and land mammal populations across the Arctic region. Seabird populations (murres have been the most studied) have shown declining population density with rising temperatures. The continued loss of sea ice will tend to favor fish species that live closer to the surface (Pelagic) over bottom-dwelling (Benthic). Many sub-Arctic species will likely expand northward into the warmer waters. Changes in water temperature and acidity are likely to adversely affect shellfish populations.
The bottom line is that many Arctic species are likely to be replaced by sub-Arctic species and Arctic species better suited to higher temperatures, declining sea ice and snow cover, and changes in vegetation. We need better data to fully understand this process.
Since Arctic ecosystems are characterized by low species diversity, they are at heightened risk of experiencing dramatic changes. The loss of a single species could have dramatic and cascading effects on an ecosystem's state and function (Post et al 2009). The current, mostly, single species approach to monitoring, with a bias towards charismatic species over functional species, limits our ability to detect and understand critical changes in the Arctic's ecosystems. A broader and more integrated approach is needed to facilitate a better understanding of how biodiversity is responding to a changing Arctic, and how these changes might reflect or counter global biodiversity trends.
Arctic Report Card, page 95
The Arctic Report Card makes it clear that the Arctic ecosystem that has existed throughout human history is rapidly changing and likely to be largely unrecognizable by 2050. Given the long life of carbon gas emissions into the atmosphere, it is probably already too late to prevent many of these changes. However, the longer it takes the human race to control its greenhouse gas emissions, destruction of carbon sinks, and overpopulation, the longer it will take for any restoration of the Arctic environment to occur.
On November 2, be sure to take a strong stand against climate zombies. Only the brain dead think the disappearance of the Arctic will be a cause for celebration. Perhaps we can enlist the help of our furry friends to show them the error of their ways.
Don't tell the kids, but Santa Claus is skating on thin ice and the reindeer are dying off.