Feeds

Study: Arctic warming at 'stunning' rate – highest temps in 44,000 years

'Anthropogenic increases in greenhouse gases led to unprecedented warmth'

Secure remote control for conventional and virtual desktops

A recent study has shown that over the past 100 years the average summer temperatures in the Eastern Canadian Arctic have been toastier than at any time for at least the past 44,000 years, and perhaps for as long as 120,000 years.

"This study really says the warming we are seeing is outside any kind of known natural variability, and it has to be due to increased greenhouse gases in the atmosphere," the study's lead, geological sciences professor Gifford Miller of the University of Colorado Boulder, said in a press release.

The study's results are detailed in a peer-reviewed paper, "Unprecedented recent summer warmth in Arctic Canada", in Geophysical Research Letters, a journal published by the American Geophysical Union.

"Our results indicate that anthropogenic increases in greenhouse gases have led to unprecedented regional warmth," the abstract for that paper concludes.

Miller and his team used radiocarbon dating to date 145 clumps of dead moss that have emerged as the ice melted in four different previously ice-bound areas of highlands of Baffin Island, finding that they were last exposed to the elements between 44,000 to 51,000 years ago.

"Since radiocarbon dating is only accurate to about 50,000 years and because Earth's geological record shows it was in a glaciation stage prior to that time, the indications are that Canadian Arctic temperatures today have not been matched or exceeded for roughly 120,000 years," is Miller's conclusion, according to the release.

Using data from ice cores recovered during previous research at the nearby Greenland Ice Sheet, Miller and his team concluded that the most recent time when Arctic summer temperatures were "plausibly" as warm as they are currently is about 120,000 years ago – which is about the same time as the end of the Earth's previous interglacial period.

"We suggest this is the most likely age of these samples," Miller said.

The study provides evidence that the current temperatures in the studied regions are now warmer than they were during the Early Holocene period – the Holocene being the period in which we are now in, and which began about 17,000 years ago at the end of the Earth's last glaciation event.

Of interest, according to Miller, is that the amount of the Sun's energy that reached the Northern Hemisphere during the Early Holocene was about 9 per cent greater than today.

The study also showed that average summer temperature in the area studied had cooled by about 5°F (2.8°C) from about 5,000 years ago to about 100 years ago – a range that included the cooling period known as the Little Ice Age, which ran from 1275 to 1900, give or take a few years, and which Miller says sediment-core studies indicate was triggered by both sun-blocking aerosols from tropical volcanic activity, along with a decrease in solar radiation.

As the Little Ice Age came to a close, the cooling reversed itself, a warming trend that started accelerating about 40 years ago. "Although the Arctic has been warming since about 1900, the most significant warming in the Baffin Island region didn't really start until the 1970s," Miller said.

"And it is really in the past 20 years that the warming signal from that region has been just stunning," he added, noting that other University of Colorado Boulder studies in Greenland show that ice-sheet temperatures have risen by 7°F (3.9°C) since 1991.

"The key piece here is just how unprecedented the warming of Arctic Canada is," Miller said. ®

Next gen security for virtualised datacentres

More from The Register

next story
Vulture 2 takes a battering in 100km/h test run
Still in one piece, but we're going to need MORE POWER
TRIANGULAR orbits will help Rosetta to get up close with Comet 67P
Probe will be just 10km from Space Duck in October
Boffins ID freakish spine-smothered prehistoric critter: The CLAW gave it away
Bizarre-looking creature actually related to velvet worms
CRR-CRRRK, beep, beep: Mars space truck backs out of slippery sand trap
Curiosity finds new drilling target after course correction
What does a flashmob of 1,024 robots look like? Just like this
Sorry, Harvard, did you say kilobots or KILLER BOTS?
NASA's rock'n'roll shock: ROLLING STONE FOUND ON MARS
No sign of Ziggy Stardust and his band
Why your mum was WRONG about whiffy tattooed people
They're a future source of RENEWABLE ENERGY
Vulture 2 spaceplane autopilot brain surgery a total success
LOHAN slips into some sexy bespoke mission parameters
LOHAN acquires aircraft arboreal avoidance algorithm acronyms
Is that an ARMADILLO in your PANTS or are you just pleased to see me?
prev story

Whitepapers

5 things you didn’t know about cloud backup
IT departments are embracing cloud backup, but there’s a lot you need to know before choosing a service provider. Learn all the critical things you need to know.
Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
Build a business case: developing custom apps
Learn how to maximize the value of custom applications by accelerating and simplifying their development.
Rethinking backup and recovery in the modern data center
Combining intelligence, operational analytics, and automation to enable efficient, data-driven IT organizations using the HP ABR approach.
Next gen security for virtualised datacentres
Legacy security solutions are inefficient due to the architectural differences between physical and virtual environments.