Last week an iceberg '
twice the size of Manhattan'
broke off a glacier in Greenland. This week, revelations surfaced that
scientists studying satellite maps of Arctic sea ice melt were so
shocked by the rapid melting of ice sheets they concluded it
was an error with their imaging equipment. It wasn't.
Since the 1970s, there has been a 40% decrease in the extent of summer sea ice. (Photograph: AlaskaStock/Corbis) These
are just the latest in a long line of 'Artic ice melting' headlines
that have dotted the newspapers over the last decade, but a new study
suggests that the trend towards Arctic ice melt is here to stay and that
at least 70% of what's creating these events is man-made interference
with the arctic ocean climate.
The new study, conducted by climate scientists at the National Centre
for Atmospheric Science at the University of Reading, found that the
loss of sea ice around the Arctic is at least 70% due to human-induced
climate change -- much higher than previously thought -- and that the number could possibly be as high as 95%.
"Since the 1970s, there's been a 40% decrease in the summer sea ice extent,"
said climatologist Jonny Day who led the latest study.
"We were trying to determine how much of this was due to
natural
variability and therefore imply what aspect is due to man-made climate
change as well."
Most concerning to the scientists is the possibility that 'feedback
loops' have already begun in which loss of ice begets increased future
loss.
"[There is] something called the ice-albedo feedback, which means
that when you have less ice, it means there's more open water and
therefore the ocean absorbs more radiation and will continue to warm,"
he said.
"It's unclear what will happen – it definitely seems like it's going in that direction."
The research is published online in the journal Environmental Research Letters.
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