Lakes across the Arctic are melting up to and more than a day earlier per year, according to a new study by scientists at a U.K. university.
The study looks at five different regions in the Arctic and gathers information from satellite images of 13,300 lakes between 2000 and 2013.
"The kinds of trends that we've got indicate that, without any doubt at all, basically almost all lakes are getting their ice-out earlier year after year," said Mary Edwards, professor of geography and environment at the University of Southampton.
"There were probably less than one per cent of lakes that were doing the opposite, or showing no trend at all."
The satellite is programmed to identify lakes on the landscape, then it takes a large image of it and sends it back down to a computer. The computer then assesses each image, identifying whether it's covered with ice or water. Each lake has a series of data for the 14-year period, noting the ice "break-up start" and "break-up end" date.
Only lakes the size of one hectare or larger are detectable.
Trends and Canada's Arctic
Lakes were analyzed in these five areas: Northern Europe, Northeast Canada, Alaskan Arctic Coastal Plain, Central Siberia, and Northeast Siberia.
There were 2,994 lakes observed in Northeast Canada and the majority of them showed a rate of change of 0.3 days earlier per year. That means the ice has been melting about eight hours earlier per year.
But 53 lakes in Canada showed a "really strong trend for earlier (ice) break-up," melting on average one day earlier per year, said Edwards.
Central Siberia showed the strongest warming trend with a melting rate of more than a day earlier per year for most of its lakes. A third of the lakes broke the highest record in the study with a change of 1.4 days earlier per year.
"If that trend will continue, in another 15 years, it would be an average of a month earlier for ice-out on a lot of these lakes," said Edwards.
Northern Europe, on the other hand, showed the least change. Lakes are melting at 0.1 days earlier per year.
"In Europe… the last 15 years or so have been actually quite cool because the North Atlantic has been in a cool mode."
'You hit it right on the nail,' says elder from Baker Lake
Edwards says these trends will affect those who live in the North.
"Using ice roads, hunting out on the tundra, all those kinds of things are going to change dramatically," she said.
David Toolooktook from Baker Lake, Nunavut, agrees.
He's been fishing, trapping, hunting out on the land for more than 45 years.
"You hit it right on the nail, right on the head," said Toolooktook about the study's results.
The study doesn't include Baker Lake because it's outside of their Northeast Canada study area, said Edwards.
"From my observation, I think it is quite noticeable that the lakes are now melting or breaking about a week, two weeks earlier than usual. Maybe even three weeks," said Toolooktook.
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"A few years back, I was able to go from one end of the lake to the other on Canada Day, July 1."
Recently, he says he hasn't been able to go that far even in mid-June.
"It affects a lot of people," he said, adding that many activities like camping, hunting and travelling in the springtime is made harder because of the ice melting earlier than usual.
Toolooktook also added that the freezing of the lake is happening later than usual.
"And the ice seems to be a little bit thinner," he said.
"I don't know if one should be concerned or not. Like I said, let the nature take its own course and we'll take it as it comes."
Consequences of early ice break-up
There are other consequences for ecosystems, says Edwards.
When the ice melts, the surface of the lake changes from white and reflective to dark; this physical change has biological effects, says Edwards.
"The water absorbs the sunlight much better. The ice tends to reflect the sunlight away, so suddenly you start heating the lake water."
That means a longer biological productivity period, which means more algae and more growth of fish.
This "might be good," says Edwards, but this may also cause the lakes to generate more greenhouse gases, warming up the environment even more.
"When you add these up, and realize that there are millions of lakes responding in this way, that's quite a feedback to the whole Arctic climate change situation."