The Arctic’s sea ice shrank by more than 2.5 million square kilometres — the size of five and a half Yukon territories — this year, setting a new record low, according to researchers.
The new record is about a million square kilometres less than the previous one, said scientists from the National and Ice Data Centre in Boulder, Colorado.
The new low was recorded by scientists on September 16, when the Artic Sea ice covered 4.13 million square kilometres.
Measurements of the ice extent have been taken annually since 1978.
The amount of ice covering the Arctic Ocean generally reaches its lowest coverage in September and highest in March.
The new data confirms much of what was said during a recent teleconference with Alaskan climate and weather researchers.
“The fact is climate change is changing Alaska,” said James Partain, US National Weather Office’s chief of environmental and scientific services division.
Researchers are no longer arguing about why climate change is occurring, but because of its urgency they are now concentrating on how to respond to it, he added.
In a teleconference with media, weather officials and environmental organizations, Partain explained how climate change is altering weather patterns and changing Alaska.
Though his presentation was focused on Alaska, the issues could pertain to Arctic countries, including Canadian territories, said Partain.
“All the research will help us understand these pan-Arctic issues,” said Partain.
“Most certainly it’s applicable to the rest of the Arctic. We have a lot of folks in Alaska collaborating with various Canadian research groups — and others in the Arctic countries — on research endeavours that are applicable to everyone.”
The ice-free area in the Arctic is 4.2 million square kilometres, the equivalent of two Alaskas and one Texas or 10 Californias, he said.
“To put that in perspective, the previous record set in 2005 has been surpassed by four times,” said Partain.
In the second week of September, the Arctic lost 98,420 square kilometres of ice.
“We certainly aren’t debating in the weather service anymore that there is warming going on all across Alaska,” said Partain.
The poles are the most sensitive regions on Earth when it comes to climate change, said the Colorado scientists.
About 80 per cent of sunlight hitting the Arctic ice is reflected, helping to keep temperatures cool.
When the ice melts exposing more ocean, about 90 per cent of the sunlight is absorbed and contributes to rising temperatures.
September measurements are made when the ice generally reaches its minimum extent, while the maximum is reached in March.
Researchers believe the ice minimum is occurring later in the season, throwing off the Arctic’s energy balance and changing climate patterns.
Measurements began in late 1978 when NASA launched satellites that pass over the polar region several times a day to gather data.
Warming of the land and sea has been taking place in Alaska for decades, said Partain.
The extent and thickness of multi-year ice has been greatly reduced, and researchers are documenting later ice freeze-ups in the fall and earlier break-ups in the spring.
Glaciers are retreating and the permafrost in melting.
Increasingly frequent extreme weather has people, such as pilots and mariners, struggling to adapt to new weather patterns.
“We have colder colds, warmer warms and wetter wets and we’re seeing more extremes and less of what we used to call normal,” said Partain.