Study: At Least 70% of Arctic Sea Ice Loss ‘Man-Made’
Scientists fear the impact of feedback loops as dramatic ice loss begets further melting
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.