Arctic ice cover hits historic low: scientists

A A A

The area covered by Arctic sea ice reached its lowest point this week since the start of satellite observations in 1972, German researchers announced on Saturday.

"On September 8, the extent of the Arctic sea ice was 4.240 million square kilometres (1.637 million square miles). This is a new historic minimum," said Georg Heygster, head of the Physical Analysis of Remote Sensing Images unit at the University of Bremen's Institute of Environmental Physics.

The new mark is about half-a-percent under his team's measurements of the previous record, which occurred on September 16, 2007, he said.

According to the US National Snow and Ice Data Center (NSIDC), the record set on that date was 4.1 million sq km (1.6 sq mi). The discrepancy, Heygster explained by phone, was due to slightly different data sets and algorithms.

"But the results are internally consistent in both cases," he said, adding that he expected the NSIDC to come to the same conclusion in the coming days.

Arctic ice cover plays a critical role in regulating Earth's climate by reflecting sunlight and keeping the polar region cool.

Retreating summer sea ice - 50 percent smaller in area than four decades ago - is described by scientists as both a measure and a driver of global warming, with negative impacts on a local and planetary scale.

It is also further evidence of a strong human imprint on climate patterns in recent decades, the researchers said.

"The sea ice retreat can no more be explained with the natural variability from one year to the next, caused by weather influence," Heygster said in an statement released by the university.

"Climate models show, rather, that the reduction is related to the man-made global warming which, due to the albedo effect, is particularly pronounced in the Arctic."

Albedo increases when an area once covered by reflective snow or ice - which bounces 80 percent of the Sun's radiative force back into space - is replaced by deep blue sea, which absorbs the heat instead.

Temperatures in the Arctic region have risen more than twice as fast as the global average over the last half century.

The Arctic ice cover has also become significantly thinner in recent decades, though it is not possible to measure the shrinkage in thickness as precisely as for surface area, the statement said.

Satellite tracking since 1972 shows that the extent of Arctic sea ice is dropping at about 11 percent per decade.

NSIDC director Mark Serreze has said that summer ice cover could disappear entirely by 2030, leaving nothing but heat-trapping "blue ocean."

The NSIDC likewise monitors Arctic ice cover on a daily basis, but has not announced record-low ice cover. Data posted on its website as of Saturday only covered the period through September 6.

By last week, it said, sea ice is almost completely gone from the channels of the Northwest Passage. The southern route - also known as Amunden's Route - was also ice free, as was the Northern Sea Route along Siberia.

But even as the thaw opens shipping lanes, it disrupts the lives and livelihoods of indigenous peoples, and poses a severe threat to fauna, including polar bears, ice seals and walruses, conservation groups say.

"This stunning loss of Arctic sea ice is yet another wake-up call that climate change is here now and is having devastating effects around the world," said Shaye Wolf, climate science director at the Center for Biological Diversity in San Francisco.

The last time the Arctic was uncontestably free of summertime ice was 125,000 years ago, during the height of the last major interglacial period, known as the Eemian.

Air temperatures in the Arctic were warmer than today, and sea level was also four to six metres (13 to 20 feet) higher because the Greenland and Antarctic Ice Sheets had partly melted.

Global average temperatures today are close to the maximum warmth seen during the Eemian.

PROMOTED VIDEO
Have you tried new the Independent Digital Edition apps?
Arts and Entertainment
Robert De Niro, Martin Scorsese and DiCaprio, at an awards show in 2010
filmsDe Niro, DiCaprio and Pitt to star
News
i100
News
In this photo illustration a school student eats a hamburger as part of his lunch which was brought from a fast food shop near his school, on October 5, 2005 in London, England. The British government has announced plans to remove junk food from school lunches. From September 2006, food that is high in fat, sugar or salt will be banned from meals and removed from vending machines in schools across England. The move comes in response to a campaign by celebrity TV chef Jamie Oliver to improve school meals.
science
Sport
England captain Wayne Rooney during training
FOOTBALLNew captain vows side will deliver against Norway for small crowd
Life and Style
Red or dead: An actor portrays Hungarian countess Elizabeth Báthory, rumoured to have bathed in blood to keep youthful
health
News
peopleJustin Bieber charged with assault and dangerous driving after crashing quad bike into a minivan
News
peopleHis band Survivor was due to resume touring this month
News
people'It can last and it's terrifying'
Life and Style
fashionModel of the moment shoots for first time with catwalk veteran
Sport
Radamel Falcao poses with his United shirt
FOOTBALLRadamel Falcao's journey from teenage debutant in Colombia to Manchester United's star signing
Life and Style
fashionAngelina Jolie's wedding dressed revealed
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
iJobs Job Widget
iJobs General

Teaching Assistant

Negotiable: Randstad Education Group: Randstad Education require a Drama speci...

Science Teacher

£120 - £162 per day: Randstad Education Hull: Science Teacher - Full Time - Lo...

Maths Teacher

Negotiable: Randstad Education Group: Randstad Education is looking for a Seco...

General Cover Teacher

£120 - £162 per day: Randstad Education Hull: Randstad Education are looking f...

Day In a Page

Chief inspector of GPs: ‘Most doctors don’t really know what bad practice can be like for patients’

Steve Field: ‘Most doctors don’t really know what bad practice can be like for patients’

The man charged with inspecting doctors explains why he may not be welcome in every surgery
Stolen youth: Younger blood can reverse many of the effects of ageing

Stolen youth

Younger blood can reverse many of the effects of ageing
Bob Willoughby: Hollywood's first behind the scenes photographer

Bob Willoughby: The reel deal

He was the photographer who brought documentary photojournalism to Hollywood, changing the way film stars would be portrayed for ever
Hollywood heavyweights produce world's most expensive corporate video - for Macau casino

Hollywood heavyweights produce world's most expensive corporate video - for Macau casino

Scorsese in the director's chair with De Niro, DiCaprio and Pitt to star
Angelina Jolie's wedding dress: made by Versace, designed by her children

Made by Versace, designed by her children

Angelina Jolie's wedding dressed revealed
Anyone for pulled chicken?

Pulling chicks

Pulled pork has gone from being a US barbecue secret to a regular on supermarket shelves. Now KFC is trying to tempt us with a chicken version
9 best steam generator irons

9 best steam generator irons

To get through your ironing as swiftly as possible, invest in one of these efficient gadgets
England v Norway: Wayne Rooney admits England must ‘put on a show’ to regain faith

Rooney admits England must ‘put on a show’ to regain faith

New captain vows side will deliver for small Wembley crowd
‘We knew he was something special:’ Radamel Falcao's journey from teenage debutant to Manchester United's star signing

‘We knew he was something special’

Radamel Falcao's journey from teenage debutant to Manchester United's star signing
'I’ll tell you what I would not serve - lamb and potatoes': US ambassador hits out at stodgy British food served at diplomatic dinners

'I’ll tell you what I would not serve - lamb and potatoes'

US ambassador hits out at stodgy British food
Radio Times female powerlist: A 'revolution' in TV gender roles

A 'revolution' in TV gender roles

Inside the Radio Times female powerlist
Endgame: James Frey's literary treasure hunt

James Frey's literary treasure hunt

Riddling trilogy could net you $3m
Fitbit: Because the tingle feels so good

Fitbit: Because the tingle feels so good

What David Sedaris learnt about the world from his fitness tracker
Saudis risk new Muslim division with proposal to move Mohamed’s tomb

Saudis risk new Muslim division with proposal to move Mohamed’s tomb

Second-holiest site in Islam attracts millions of pilgrims each year
Alexander Fury: The designer names to look for at fashion week this season

The big names to look for this fashion week

This week, designers begin to show their spring 2015 collections in New York