Arctic "death spiral" leaves climate scientists shocked and worried

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Sep 21, 2012, 12:27:35 PM9/21/12
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Arctic "death spiral" leaves climate scientists shocked and worried

(For charts & graphs, see article at
http://www.vancouverobserver.com/blogs/climatesnapshot/arctic-death-spiral-leaves-climate-scientists-shocked-and-worried)

A "radical shift" is plunging the Arctic Ocean towards an ice-free state
for the first time in millions of years. One of the world's foremost ice
experts, Professor Peter Wadhams of Cambridge University, calls it a
"global disaster" that will cause such a big boost in global temperatures
that even such extreme measures as geo-engineering need to be considered
urgently.

Climate science has long understood that disappearance of summer sea ice
in the Arctic would be a "tipping point" in the Earth's climate system,
accelerating global temperatures and causing extreme weather and other
climate changes far beyond the Arctic. Yet nearly every expert has been
shocked by just how rapidly this "continent of ice" has been vanishing,
and how dramatic the impacts have been already.

Climate scientists and ice experts are now using phrases like
"unprecedented", "amazing", "extreme", "hard to exaggerate", "incredibly
fast", "death spiral" and "heading for oblivion".

Arctic sea ice has been a permanent, year-round fixture of our planet
since long before Homo sapiens first appeared on the savannas of Africa as
a new species. Despite being robust enough to survive every change Mother
Nature threw at it for millions of years, Arctic sea ice has proven to be
shockingly vulnerable to a few decades of humanity's unrestrained fossil
fuel pollution.

The trillion tonnes of CO2 pollution that people have released into the
atmosphere from burning oil, coal and natural gas has acted like a blow
torch on Arctic ice. A dozen pounds of Arctic sea ice has disappeared for
every one pound of CO2 we have released. This highlights the incredible
heating power of CO2 which pumps 100,000 times more energy into our
climate than was given off when the oil, coal or natural gas was burned.

CO2 has been the "Energizer Bunny" of extreme weather, pumping energy into
our climate non-stop for centuries.

As my the chart above shows, three-quarters of the "permanent", year-round
sea ice in the Arctic has been cooked away in just 30 years. Over half of
it has disappeared in just the last eight years. A vast expanse of ice
larger than the European Union has vanished. What's left is half the area
and only half as thick.

Now some ice experts are saying what remains could be gone in as little as
ten years -- or even four.

Worse than worst case

This jaw-dropping acceleration of Arctic sea ice collapse is completely
out-stripping the worst case scenarios of the UN International Panel on
Climate Change (IPCC). The IPCC reports are the primary source of climate
science used by world leaders, policy makers, businesses and citizens to
decide the urgency and level of action needed.

The most recent IPCC report includes this graphic on the right. It
predicts summer sea ice surviving long after most people alive today will
have died of old age.

It is easier for decision makers to procrastinate on a difficult task if
they don't think it will become critical for generations.

And sure enough, humanity has procrastinated badly in tackling the climate
threat. The amount of fossil fuel CO2 pollution the world is pumping out
every year is still increasing, even as extreme weather and climate shifts
are accelerating.

The IPCC predictions come from a suite of the best global climate models
at the time. Below is a chart showing the predictions of the IPCC global
models used in their most recent report. For comparison I've added a bold
orange line showing the best estimates -- based on multiple modes of
observations -- for what has actually happened.

These IPCC models are off by many decades -- whole generations, in fact.
New models are being developed for the next IPCC report. They have been
described as "less bad" in some ways but they still fail to offer any
better guidance than the old models on how quickly summer ice will vanish.
At this rate the ice will be gone before we can we can build models to
tell us that.

The orange "best estimate" values on the chart come from a University of
Washington project called PIOMAS. For years many experts were sceptical of
PIOMAS ice loss estimates because they were so extreme and because humans
didn't have complete high quality data for ice volume. Could they be
wildly wrong?

Unfortunately, the answer is no. Two years ago, the European Space Agency
launched a satellite (CryoSat-2) specifically designed to very accurately
measure sea ice volume. The results from the first two years have
confirmed the PIOMAS estimates. Three quarters of the summer ice volume
really seems to have vanished.

A recent CBC report on these CryoSat-2 results was blunt: "Arctic ice
could vanish in 10 years, scientists warn … Arctic sea ice is melting at a
pace so much faster than once thought that the latest projections say it
might disappear by as soon as 2022."

Professor Wadhams, whose predictions of rapid ice loss have so far been
among the most accurate, told the Guardian he thinks summer Arctic sea ice
could vanish within four years.

Once again we are being caught off guard as the actual pace of climate
change is unfolding far more rapid than the conservative IPCC estimates
used by policy makers, businesses and citizens worldwide. These
conservative estimates have encouraged a tepid policy response. Further
encouraging foot-dragging on climate action has been a well-organized,
well-funded campaign of fake climate skeptics attacking the science and
scientists that sought to alert humanity to the need to act more quickly.

Just how badly have we dithered in removing climate pollution -- and the
economic risk that goes with it -- from the global economy? Take a look:
(For charts & graphs, see article at
http://www.vancouverobserver.com/blogs/climatesnapshot/arctic-death-spiral-leaves-climate-scientists-shocked-and-worried

The chart above shows the ever increasing amount of fossil fuel CO2 that
humans are releasing each year. Not only are we pouring lots more fuel
into global warming each year, we are also doing it at a rate that was
considered a worst case scenario by the IPCC just a decade ago.

Clearly we have persuaded ourselves that climate damages would unfold
slowly over a century or more. But now in the Arctic we have again drawn
the short straw.

All that vanishing sea ice is amplifying global warming and extreme
weather far beyond the Arctic. A series of global warming feedback loops
--- outside of our direct control -- are emerging already. As one climate
scientist put it: "What happens in the Arctic doesn’t stay in the Arctic."

As the meltdown continues the impacts are expected to get worse.

Here is a quick overview of some of the big, currently known, impacts...

Read more:
http://www.vancouverobserver.com/blogs/climatesnapshot/arctic-death-spiral-leaves-climate-scientists-shocked-and-worried?page=0,1

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