After yet another historically warm Northern Hemisphere winter, Arctic sea ice levels have hit a new low.
That’s according to the National Snow and Ice Data Centre (NSIDC) and NASA, which released findings showing the maximum extent of sea ice in the Arctic Ocean, typically set near the start of spring after the ice has grown all winter, is at the lowest it’s ever been.
As the Arctic sea ice levels reach a record winter low researchers say the repercussions are being felt throughout the entire ecosystem.
A team from the University of Colorado’s NSIDC conducted the analysis of Arctic sea levels alongside NASA, and found the winter sea ice was smaller this year at the maximum extent.
Its lowest average was 14.52 million square kilometres on March 24, compared to last year’s record low of 14.54 million sq/km on February 25.
“What usually happens at this time of year was reached March 24, and the total area that’s covered by sea ice in the Arctic is smaller this year than it’s been at any time in the last 37 years,” lead researcher Dr Ted Scambos said.
Dr Scambos said that the recorded results were attributed to a number of reasons, including the warmer conditions that persisted throughout the winter months.
“We had very warm conditions throughout the Arctic at higher latitude up to two to six degrees Celsius warmer than usual,” he said.
“And what that means is the interior of the Arctic is always quite cold and below freezing, near the edges, though, where it’s warmer than average, it means that the growth of sea ice as it spreads outwards from the pole is slower than it would be otherwise.”
“It’s also due to wind direction and influence from warm ocean currents that are flowing towards the Arctic, especially in the north Atlantic,” he said.
“All these things combine to give us this record low.”
Dr Scambos said scientists would start to see large areas of the Arctic ocean remain open water for several weeks at the end of summer.
“Different folks have different ideas about how having a large area of open water will affect climate in the northern hemisphere and the onset of winter and the amount of snowfall on land, or the intensity of storms in the northern hemisphere, all of those things remain to be sorted out,” he said.
“But that it’s going to have an impact on climate, I don’t think there’s any doubt that changing the Earth’s system in such a drastic way is going to have a big impact.”
Dr Scambos said the consequences of these record lows could include coastal erosion, weather patterns and the health of Arctic animals.
“In some places, coastline is exposed to ocean waves for a much longer period of time during the year than used to be the case and so you get a lot of coastal erosion, this is in the high Arctic,” he said.
“In some places, the weather is affected quite a bit; for example in Scandinavia and in Svalbard it’s a very different winter when there’s ice off the coast versus when there’s a large area of open water off the coast.
“The bigger concern is how summer sea ice reduction may begin to impact northern hemisphere climate in the summer months and early fall months.”
“Because their environment is changing, because ways they are used to feeding don’t work so well or the areas are more restricted than they used to be, it forces them into situations that aren’t as favourable for them,” he said.
“Same with polar bears, if they’re forced to try to forage on land or near coastlines, or even near villages where there’s food available it is very difficult and they have to be removed eventually.”