Scientists call Times World Atlas Greenland claims 'incorrect and misleading'
- 19 Sep 2011, 13:39
- Christian Hunt
With Arctic sea ice just past its annual summer
minimum, interest in the Arctic has reached its annual peak.
Perhaps timed to coincide with the sea ice minimum, the marketing
effort accompanying the launch of the new edition of the Times
World Atlas leaned heavily on the redrawn maps of Greenland
featured in the atlas, which appear to show the ice cap in
retreat.
But now scientists have raised questions about how the Atlas came
to their conclusions about the ice cap, about the
press release put out to mark the publication of the 13th
edition of the definitive tome, and about the maps
themselves.
The press release claimed:
For the first time, the new edition of
The Times Comprehensive Atlas of the World, published on 15
September, has had to erase 15% of Greenland's once permanent ice
cover - turning an area the size of the United Kingdom and Ireland
'green' and ice free… Cartographers of the atlas have sourced the
latest evidence and referred to detailed maps and records to confirm
that in the last 12 years, 15% of the permanent ice cover (around
300,000 sq km) of Greenland, the world's largest island, has melted
away.
Needless to say, this story was
widely picked up.
ITN covered the story and interviewed the Atlas' editor, and it
reached the Australian
Daily Telegraph and the UK's Daily
Express, while John Vidal
writing in the Guardianrepeated the press release's claim:
The world's biggest physical changes in
the past few years are mostly seen nearest the poles where climate
change has been most extreme. Greenland appears considerably
browner round the edges, having lost around 15%, or 300,000 sq km,
of its permanent ice cover.
Research
into the Greenland ice sheet confirms that it is losing ice as
the Arctic region warms. But concerns were raised on Twitter when
scientists contacted the Guardian suggesting that the figures they
had quoted were questionable.
The BBC
reports that scientists from the Scott Polar Research
Institute, University of Cambridge, have written a letter to the
Times taking issue with the erroneous 15% claim.
The problem with the 15% claim is that the Times Atlas maps seem
to be at odds with in-situ and satellite measurements, showing
areas of Greenland as ice-free when they are in reality covered by
ice. The letter says:
"Recent satellite images of Greenland
make it clear that there are in fact still numerous glaciers and
permanent ice cover where the new Times Atlas shows ice-free
conditions and the emergence of new lands...We do not know why this
error has occurred, but it is regrettable that the claimed drastic
reduction in the extent of ice in Greenland has created headline
news around the world. There is to our knowledge no support for
this claim in the published scientific literature."
The scientists note that the Greenland ice sheet is losing mass
due to climate change, saying:
"We do not disagree with the statement
that climate is changing and that the Greenland Ice Sheet is
affected by this."
However, the Greenland ice loss is not anything like the rate
claimed by the Times World Atlas team. In the letter to the Times,
the scientists note:
"It is... crucial to report climate
change and its impact accurately and to back bold statements with
concrete and correct evidence"
The BBC reports that a HarperCollins spokesperson has suggested
that the new map is based on information from the US National Snow
and Ice Data Center (NSIDC). The NSIDC make numerous data sets
available on their website , and
it's not clear whether the Atlas team just meant that they based
their work on NSIDC measurements. It seems fair to say that the
reaction of UK polar scientists to the story suggests it's unlikely
that the World Atlas team consulted closely with scientific
experts.
It's unclear what methodology the Atlas team used to plot ice
retreat, but scientists we spoke with speculated that the
cartographers might have confused the thickness of the ice with its
elevation. This would have led to mangled results, as the ground
beneath the ice sheet is uneven, and in places the ice cap sits on
top of mountain ranges.
We asked the Atlas team for more details of their methodology.
We'll update the blog post when they respond.