Arctic
ice melt could trigger uncontrollable climate change at global level
Temperatures
in the Arctic are currently ‘off the charts’ at about 20C above
expected
Scientists
warn increasingly rapid melting could trigger polar ‘tipping
points’ with catastrophic consequences felt as far away as the
Indian Ocean
Fiona Harvey
Friday 25 November
2016 05.01 GMT
Arctic scientists
have warned that the increasingly rapid melting of the ice cap risks
triggering 19 “tipping points” in the region that could have
catastrophic consequences around the globe.
The Arctic
Resilience Report found that the effects of Arctic warming could be
felt as far away as the Indian Ocean, in a stark warning that changes
in the region could cause uncontrollable climate change at a global
level.
Temperatures in the
Arctic are currently about 20C above what would be expected for the
time of year, which scientists describe as “off the charts”. Sea
ice is at the lowest extent ever recorded for the time of year.
“The warning
signals are getting louder,” said Marcus Carson of the Stockholm
Environment Institute and one of the lead authors of the report.
“[These developments] also make the potential for triggering
[tipping points] and feedback loops much larger.”
Climate tipping
points occur when a natural system, such as the polar ice cap,
undergoes sudden or overwhelming change that has a profound effect on
surrounding ecosystems, often irreversible.
In the Arctic, the
tipping points identified in the new report, published on Friday,
include: growth in vegetation on tundra, which replaces reflective
snow and ice with darker vegetation, thus absorbing more heat; higher
releases of methane, a potent greenhouse gas, from the tundra as it
warms; shifts in snow distribution that warm the ocean, resulting in
altered climate patterns as far away as Asia, where the monsoon could
be effected; and the collapse of some key Arctic fisheries, with
knock-on effects on ocean ecosystems around the globe.
The research,
compiled by 11 organisations including the Arctic Council and six
universities, comes at a critical time, not only because of the
current Arctic temperature rises but in political terms.
Aides to the US
president-elect, Donald Trump, this week unveiled plans to remove the
budget for climate change science currently used by Nasa and other US
federal agencies for projects such as examining Arctic changes, and
to spend it instead on space exploration.
“That would be a
huge mistake,” said Carson, noting that much more research needs to
be done on polar tipping points before we can understand the true
dangers, let alone hope to tackle them. “It would be like ripping
out the aeroplane’s cockpit instruments while you are in
mid-flight.”
He added: “These
are very serious problems, very serious changes are happening, but
they are still poorly understood. We need more research to understand
them. A lot of the major science is done by the US.”
Scientists have
speculated for some years that so-called feedback mechanisms – by
which the warming of one area or type of landscape has knock-on
effects for whole ecosystems – could suddenly take hold and change
the dynamics of Arctic ice melting from a relatively slow to a
fast-moving phenomenon with unpredictable and potentially
irreversible consequences for global warming. For instance, when sea
ice shrinks it leaves areas of dark ocean that absorb more heat than
the reflective ice, which in turn causes further shrinkage, and so on
in a spiral.
The Arctic ice cap
helps to cool sea and air temperatures, by reflecting much of the
sun’s radiation back into space, and acting as a global cooler when
winds and ocean currents swirl over and under it. It has long been
known to play a key part of the global climate system, but the
difficulty and expense of close monitoring have meant that scientists
have only in recent years been able to make detailed assessments.
The report, billed
as the first comprehensive study of ecosystems and societies in the
region, found: “The potential effects of Arctic regime shifts [or
tipping points] on the rest of the world are substantial, yet poorly
understood. Human-driven climate change greatly increases the risk of
Arctic regime shifts, so reducing global greenhouse gas emissions is
crucial to reducing this risk.”
The authors also
warned that people living in and near the Arctic would be badly
affected, and called for communities to be provided with equipment
and skills to survive. They took evidence from a variety of
settlements in the region, finding many signs of stark changes
already under way.
Joel Clement,
co-chair of the project and director of the office of policy analysis
at the US Department of the Interior, said: “This groundbreaking
report is an unprecedented effort to gain insight from what is
happening on the ground. The findings are foundational to a more
informed, coordinated response to building resilience across the
region.”
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