Three reasons to care about the Arctic
Climate change is melting Arctic coastlines by 30 metres each
year, scientists claim" reports the Mail. "
Arctic coastlines recede by 'several metres' a year" the
So what's the story behind the headlines?
A new report, The
State of the Arctic Coast 2010 has been
released and it is based on a major undertaking. More than 30
scientists from 10 countries studied around a quarter of the entire
Arctic coastline, 100,000 km in all. They assessed the
physical, ecological and social impacts of environmental
The report emphasises the importance of the Arctic coast,
"…a locus of human
activity, a rich band of biodiversity, critical habitat, and high
productivity, and among the most dynamic components of the
The Arctic coast supports the majority of indigenous communities
in the area as well as very large populations of fish, mammals and
birds, providing habitat for 500 million seabirds alone.
The amount of Arctic sea ice has been declining at around 13%
per decade since satellite records began in 1979. The last
decade has seen the warmest temperatures on record over Greenland
and Canadian Arctic, whilst the summer sea ice cover has continued
to decline - reaching successive record lows in 2002 and 2007.
This, and the fact that the remaining sea ice is becoming thinner,
means that seasonally ice-free Arctic seas have become a more
imminent prospect. This puts the coast at risk.
Key findings in the report include:
Arctic coastlines more vulnerable than those at lower
Loss of sea ice means that there is a greater expanse of open
water in the Arctic Ocean, in which strong waves can form. The
resulting larger waves, combined with warmer, stormier seas leads
to faster coastal erosion.
The research sites a report
showing that on average Arctic coastlines are losing around half a
metre to erosion per year - and, as the Daily Mail reported, the
coast is retreating at a rate of 10-30 metres a year at the very
highest level. The highest mean erosion rates are in the Beaufort,
the East Siberian, and the Laptev seas.
Rocky coastlines can withstand the increase in waves and storms
reasonably well. However, three quarters of the coastline that
meets the Arctic Ocean consists of permafrost (frozen sediments).
The high ice content of permafrost makes it especially susceptible
to erosion, particularly as temperatures in the Arctic
Gas hydrates could cause release of methane
Gas hydrate deposits are crystals made of ice and methane that
form under high pressures and low temperatures, such as when
permafrost gets buried. Small increases in temperature or a release
in pressure can cause the gas hydrates to become unstable and
decompose, releasing methane (a potent greenhouse gas) into the
atmosphere. There is a possibility that the rising Arctic
temperatures and coastal erosion could destabilise the gas hydrate
deposits found there. This would act as a positive feedback,
causing more Arctic warming.
Impacts on Arctic coastal communities
The accelerated coastal erosion damages the infrastructure of
coastal communities - so much so that some communities are having
to consider relocation. Storm
surges arising in warm, open waters also have a big impact on
low-lying coastal areas, adversely affecting coastal communities
and ecosystems. For example, surges can break up ice roads (vital
transportation links in winter) and contaminate freshwater systems
with salty water. In addition, many of the subsistence communities
rely heavily on having healthy coastal ecosystems. As noted by one
of the authors:
"Hunting, fishing and gathering is
important for large parts of the Arctic population both for food
(and thus economic reasons), nutrition, cultural identity and
This dependence is increasing threatened by the changing
This is a powerful report, well worth reading in more detail,
and full of interesting nuggets of information. It also adds to the
ever-increasing wealth of information about why we should care
about what is happening to the Arctic.