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2003 and 2008 point to dissolved methane concentrations in these coastal waters
that are supersaturated with respect to the atmosphere, implicating a seabed source.
A subsequent observational study (Shakova et al., 2013 ) lends further credence to
the view of the East Siberian shelf as an important region of methane release, but
highlights the importance of direct transport to the atmosphere as bubbles. Through
mixing processes, the passage of storms appears to enhance the bubble-associated
methane release. They argue that as sea ice extent declines and winds have a longer
fetch over open water, this storm-induced mixing will become more pronounced.
However, the prevailing view is that an alarmist attitude is unwarranted. Global
methane levels increased up until the late 1990s, and then leveled off. Although
levels then started to rise again in 2007, there is little evidence that this jump was
because of melting hydrates or thawing terrestrial permafrost. Methane stopped
increasing in the Northern Hemisphere in 2008. Arctic methane release is likely to
happen fairly slowly, as it takes time for the oceans to warm and for that warmth to
penetrate into the hydrates. The methane then has to get through the thick sediments
(Kerr, 2010 ).
11.4
Human Responses to a Changing Arctic
The future is likely to see considerable disruption of traditional Arctic lifestyles.
The reasons are many, and include impediments to travel because of changing sea
ice and snow conditions, changes in the abundance, location, and habits of spe-
cies harvested by indigenous peoples, and changing economics. Indeed, as marine
access improves, the Arctic is likely to become a much busier place than today,
with strategic implications for Canada, Denmark, Norway, Russia, and the United
States, in particular (AMSA, 2009 ). The shelf seas of the Arctic Ocean in particu-
lar hold considerable reserves of oil and natural gas that remain to be exploited but
will become more accessible as the ice-free season in these areas grows in length
and winter ice conditions become milder. Milder ice conditions will also make it
easier to exploit hard minerals. Supporting these activities will naturally lead to
an increase in ship traffic. There has been considerable discussion regarding pros-
pects for increased commercial shipping across the Arctic Ocean via the Northwest
Passage or the Northern Sea Route ( Figure 1.1 ) and there have been numerous ship
passages in recent years to demonstrate the viability of these routes.
A reliable Arctic Ocean shortcut might attract increased tourism along with com-
mercial shipping, but economic viability is very much open to question. First, for
the foreseeable future, there will be substantial winter sea ice, meaning that these
passages will be open only on a seasonal basis. Because of strong interannual var-
iability in Arctic climate, for decades to come, these passages are unlikely to be
open every year. Second, Arctic maritime infrastructure is at present inadequate and
would require substantial investment, including aids to navigation, port facilities,
icebreaking escort, ship tracking, oil spill prevention and response, environmental
monitoring, and search and rescue capabilities. Another issue is competition - by
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