The Arctic could soon be completely free of sea ice each year during its transition from summer to winter, even if we hit temperature goals proposed by the Paris Agreement, a shocking new study has found.
Global temperature increase of just 2 to 2.5 degrees Celsius puts the Arctic at risk of being iceless through the month of September, when the region typically reaches its minimum following the brief polar summer.
An ice-free autumn also means it would be harder for the ice to bounce back over the course of winter, potentially spelling disaster for seals, polar bear, and other wildlife that depend on the ice to find food and raise their young.The ominous predictions come from a study led by the University of Cincinnati and published in the journal Nature Communications.
In the study, researchers attempted to find out the point at which ice levels go from slim to none altogether by applying statistical methods to the latest climate model projections.
Ice in the Arctic fluctuates greatly along a seasonal cycle. But, rising global temperatures have driven dramatic changes in the area.
‘The target is the sensitivity of sea ice to temperature,’ says Won Chang, a study co-author and UC assistant professor of mathematics.
‘What is the minimum global temperature change that eliminates all Arctic sea ice in September? What’s the tipping point?’
According to the researchers, that tipping point could be as low as just 2 degrees of warming.
While a temperature spike of 1.5 degrees C above pre-industrial levels makes for only a 6 percent probability of an ice-free Arctic Ocean during the summer, this jumps to 28 percent at 2 degrees, the team found.
That means even with efforts guided by the Paris Agreement, the Arctic Ocean could see dramatic ice loss during its minimum.
‘Most likely, September Arctic sea ice will effectively disappear between approximately 2 and 2.5 degrees of global warming,’ according to the study.
‘Yet limiting the warming to 2 degrees (as proposed under the Paris agreement) may not be sufficient to prevent an ice-free Arctic Ocean.’
September is the month in which the Arctic has the least ice cover annually.
But soon, the team warns, it may have no sea ice at all.
‘They use September as a measure because that’s the transition period between summer and winter in the Arctic,’ Chang said.
‘Ice recedes from June to September and then in September it begins to grow again in a seasonal cycle.
‘And we’re saying we could have no ice in September.’