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Is arctic melting reaching a tipping point?
THE BBC reports (28 September): "Arctic ice
‘disappearing quickly’. The area covered by sea ice in the Arctic has
shrunk for a fourth consecutive year, according to new data released by
US scientists". At the current rate, the Arctic polar ice cap will
disappear by 2060, far sooner than previous estimates.
It looks like we are seeing a "positive feedback
effect, a ‘tipping-point’", says Mark Serreze of the National Snow and
Ice Data Center (NSIDC) in Boulder, Colorado, USA. A tipping point is a
situation when additional quantities (in this case of greenhouse gasses)
lead to a qualitative change – the thing tips and suddenly everything
slides.
Are we seeing a tipping point, where the world
experiences sudden catastrophic changes caused by global warming?
Malcolm Gladwell popularised the term in his book, The Tipping Point:
How Little Things Can Make a Big Difference, although the concept was
known even in ancient Greece. Marxists call it the ‘transformation of
quantity into quality and vice versa’, and it is very real. The loss of
the Arctic ice together with other melting on its own could lead to seas
rising between 30-88cm by the end of this century, but more importantly,
"the Arctic played a fundamental role in regulating the Earth’s
climate", according to Terry Callaghan, an Arctic ecologist who helped
produce the Arctic Climate Impact Assessment published last year. This
is not to mention the destruction of wildlife habitat.
If this tipping point leads to neighbouring
Greenland’s ice melting, it will raise sea levels by seven metres. At
current rates this would take thousands of years. But the speed at which
Greenland’s glaciers are sliding into the sea has already tripled. The
Kangerdlugssuaq glacier now moves at 1.6 metres an hour, three times as
fast as in 1988. This is almost as fast as the speediest glacier, the
Jakobshavn Isbrae. Between them, they comprise 10% of Greenland’s ice.
Global warming tipping points in the northern
hemisphere include the feedback effect of the melting of Arctic ice
itself, which increases the ability of the sea to absorb sunlight and
warm up. The Arctic ice reflects 80% of sunlight, whilst water only
reflects 20%. The melting of the permafrost, a permanently frozen layer,
under about one fifth of the world’s landmass, is cited as another
tipping point, which will release methane, a powerful greenhouse gas,
ten or twenty times as powerful as carbon dioxide.
Ice cores extracted from the Arctic and Antarctic
ice sheets provide clues that suggest previous tipping points in the
earth’s development. Startling rises in the earth’s temperature, thought
to have taken thousands of years, in fact happened in almost an instance
of geological time. In late 2001, scientists identified one possible
cause of this sudden change – the release of methane frozen beneath the
sea.
Trapped at the bottom of the oceans is about 3,000
times the amount of methane in the atmosphere. It enters the oceans
through ‘cold seeps’ – the cold equivalent of thermal vents, with their
own ecology, including, believe it or not, one- or two-inch ice worms
that burrow in the methane hydrate (a chemical compound of methane and
water) that freezes there.
The top story on the Goddard Space Flight Centre
website (10 December 2001) reported: "A tremendous release of methane
gas frozen beneath the sea floor heated the earth by up to 13 degrees
Fahrenheit (7 degrees Celsius) 55 million years ago, a new NASA study
confirms". That was a significant tipping point, and another event of
this kind could result in runaway global warming.
Will the fate of New Orleans after hurricane Katrina
this year be repeated around the world if Greenland’s ice melts and seas
rise seven metres? Parts of New Orleans flooded to eight metres – but it
was preventable. The New Scientist reported (22 September): "Scientists
claim faulty construction or poor maintenance led to breaches [in the
levees] rather than the walls being over-topped by water".
The October edition of Socialism Today showed how
cuts in the Federal budget led to this avoidable tragedy. But if the
richest country in the world cannot protect its poorest citizens, the
outlook for the Indian subcontinent, particularly low-lying Bangladesh,
looks very poor under capitalism.
Ancient feudal despots of the Indian subcontinent
generally preserved the infrastructure of the lands they conquered,
Friedrich Engels pointed out, until British imperialism’s rule when
these structures – such as irrigation – were abandoned, resulting in
"regularly recurring famines". (Anti-Duhring II, IV) These famines
marked the descent into hell for the poor peasants and workers of the
region, and the lack of defence against ‘natural’ disasters (including
the destruction caused by the recent earthquake) is a long-term
consequence.
Should the oceans’ waters rise, whilst not
trivialising the issue, it is not beyond the ingenuity of people to take
effective precautions, only given their own democratic control and
management over the resources of the planet – a socialist society and
careful planning. (The same applies to building schools and blocks of
flats adequate to withstand the known potential strength of
earthquakes.) The same democratic socialist plan, with the world’s
resources at its disposal, would be the powerhouse behind finding a
solution to stabilising the planet’s environment – but the clock is
ticking.
The Arctic ice has shrunk from around 7.5 million
kilometres two decades ago, to roughly 5.5 million km today, a new
record. Opponents of the observed global thawing argue that the earth is
recovering from the ‘little ice age’ which caused the Thames to freeze
over at its peak in the 17th century, and which lasted roughly from the
14th to the 19th century. Ice sheets and glaciers are still experiencing
the effects of this warming, they claim, and the Antarctic seems to be
invulnerable, with no observed warming. (If the Antarctic melted, oceans
would rise 80 metres.) The ice in the northern hemisphere may be "piling
up along the north Canadian coast", says Professor Morris of the British
Antarctic Survey, but "we wouldn’t expect to have four years in a row of
shrinkage. That, combined with rising temperatures in the Arctic,
suggests a human impact".
Global warming after this little ice age has caused
Mount Kenya to lose seven of its 18 glaciers since 1900, reports Fred
Pearce in the New Scientist (27 August 2005). Sceptics of global warming
claim this is due to random variations in snow precipitation. But Mount
Kilimanjaro has had ice for at least 11,000 years, yet it has now lost
80% of its ice, and it looks like losing the rest in less than 20 years.
The Antarctic ice core, drilled down more than two
miles, reveals that current concentrations of the greenhouse gas, carbon
dioxide (CO2), at over 350 parts per million (ppm), are
higher than in the last 450,000 years. CO2 regularly peaked
at little more than 250 ppm in this period. By comparison, the current
sudden rise in CO2 emissions is literally stratospheric. In
addition, the current atmospheric methane level is about 230% of its
pre-industrial maximum.
Europe’s biggest glacier, the Breidamerkurjokull in
Iceland, has been shrinking for most of the past century. But most
scientists agree, with vast amounts of data available and a range of
accurate global climate models, that the warming since the little ice
age in the previous centuries merely overlapped with the human-made
warming since the beginning of the industrial age. Human causes are the
only known factors that can account for the rapid reduction of the North
Pole’s ice.
Pete Mason
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