Environmental Science & Engineering - www.esemag.com - March 2003
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Ancient logbooks provide new insight on climate change
The five-hundred year old logbooks
of long-dead arctic
explorers are helping to reveal
the impact of climate change
on arctic sea ice, the World Wildlife
Fund and the Norwegian Polar
Institute (NPI) announced on February
21.
Entries from the explorers' logbooks,
which record where they
encountered sea ice, as well as the
weather they sailed through and even
the whales they caught, have been used
to produce historical sea-ice charts.
These now form part of a series of
6,000 charts which run from the mid-
1500s up to the present day and will
allow scientists to improve understanding
of climate variability and changes
in north-west Europe and the Arctic
over the last five hundred years.
Changes in sea ice impact many
species such as polar bears and seals,
which hunt and breed on the ice.
"Much has been made in recent
years of the connection between global
warming and sea ice extent," said
Lynn Rosentrater, WWF's International
Arctic Programme climate
change scientist. "But, prior to the
development of satellites, few direct
observations of sea ice were made in
any systematic manner. This new
dataset will make it easier to identify
the impacts of climate change in the
Arctic."
Studies have shown that the extent
of sea ice, an indicator of climate variability
and change, has decreased in
the Arctic Ocean in the past 30 years in
line with global warming trends.
Existing analysis of the new charts
shows that this is a trend which goes
back at least 150 years. The new
archive will allow scientists to investigate
variations in ice extent as far back
as the 16th Century.
The Arctic Climate System Study
(ACSYS) Historical Ice Chart Archive
- created by NPI and the Norwegian
Meteorological Institute, and published
with funding from WWF - provide
some of the oldest records of climate
change observations in existence,
covering an area from Greenland in the
west to Novaya Zemlya in the east
from as early as 1553 to 2002.
The earliest records used in the
archive come from Sir Hugh
Willoughby, an Englishman with no
nautical experience whatsoever, who
set sail from London in 1553 to find a
northeast sea route to China. The expedition
was the first of the delightfully
named Mystery and Company of
Merchant Adventurers for the
Discovery of Regions, Dominions,
Islands, and Places Unknown to find
new trade routes with the rich Orient.
It was also the last. Although secondin-
command Richard Chancellor survived
to establish new trade deals with
Russia, Willoughby's ship became
trapped in sea ice near Murmansk and
he and his crew perished.
"This archive is one of the longest
directly-observed records of any climate
variable in existence, and represents
the culmination of 15 years of
work, initiated by renowned Norwegian
sea-ice scientist, Torgny
Vinje," said Chad Dick, Director of the
International Arctic Climate System
Study Project Office at NPI. "But we
are also indebted to the captains and
sailors who braved the Arctic conditions
hundreds of years ago and who
kept such careful note of their observations.
Because of their efforts, scientists
will be able to assess the current
retreat of sea ice in the light of variations
over several centuries."
Contact: jwoolford@wwf.no
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