Nav: Home

Arctic sea ice loss in the past linked to abrupt climate events

February 11, 2019

A new study on ice cores shows that reductions in sea ice in the Arctic in the period between 30-100,000 years ago led to major climate events. During this period, Greenland temperatures rose by as much as 16 degrees Celsius. The results are published today (Monday 11 February) in Proceedings of the National Academy of Sciences (PNAS).

A team from British Antarctic Survey (BAS), University of Cambridge and University of Birmingham studied data from ice cores drilled in Greenland. They looked at oxygen isotopes and compared them to climate models run on the ARCHER supercomputer1. From this they determined that sea ice changes were massively significant in past climate change events in the North Atlantic. These periods, called Dansgaard-Oeschger events2, are some of the fastest and largest abrupt climate changes ever recorded. During some of these events, Greenland temperatures are likely to have increased by 16 degrees Celsius in less than a decade.

Lead author, Dr Louise Sime, a climate scientist at BAS says:

"For years scientists have been puzzled about the correlation between Arctic sea ice loss and the extreme climate events found in the ice core record. There were at least four theories being mooted and for two years we've been investigating this problem. I'm delighted that we have proven the critical importance of sea ice using our numerical model simulations.

"The summer time sea ice in the Arctic has experienced a 40% decline in the last few decades, but we know that about two thirds of that reduction is caused by human-induced climate change. What we now need to determine is, what can be learnt from these past sea ice losses to enable us to understand what might happen next to our climate3."

Dr Rachael Rhodes, an ice core scientist from Northumbria University says:

"Now that we better understand how sea ice loss is imprinted on Greenland ice cores, we move closer to deciphering between different theories about what triggered these remarkable climate events."

This work confirms a major significance of sea ice for past abrupt warming events. This is important because changes in sea ice have profound consequences on both global and local scales, including impacts on global climate and local ecosystems. Accurate forecasts of Arctic sea ice over the coming decades to centuries are crucial to understanding how the earth will respond to any changes.

Impact of abrupt sea ice loss on Greenland water isotopes during the last glacial period by Louise C. Sime, Peter O. Hopcroft, Rachael H. Rhodes is published in the Proceedings of the National Academy of Sciences.
-end-
Issued by the British Antarctic Survey Press Office: Athena Dinar, senior science communications manager tel: +44 (0) 1223 221441, e: amdi@bas.ac.uk
Mobile: +44 (0) 7909 008516

Photographs are available on request from the Press Office.

Notes to Editors

1.The researchers' numerical model simulations were run on the large ARCHER supercomputer. ARCHER is based around a Cray XC30 supercomputer and is provided by EPSRC, NERC, EPCC, Cray Inc. and The University of Edinburgh. The simulations were run over the course of two years and were compared to ice core data that has been collected over the last twenty to thirty years.

2. Dansgaard-Oeschger events are rapid climate fluctuations that occurred about 25 times during the last glacial period. They are named after Willi Dansgaard who was a Danish paleoclimatologist (1922-2011) and Hans Oeschger (1927-1998), another paleoclimatologist, who jointly identified them in Greenland ice core records.

3.Following on from this work, Dr Sime alongside her European partners, have now won an 8 million EUR grant from the EU to develop our understanding of risk from abrupt climate change events. They will develop the underpinning science for safe operation of the Earth system. This will help us understand the risk of crossing climate tipping points, particularly due to Arctic and Antarctic sea ice loss.

British Antarctic Survey

Related Sea Ice Articles:

Melting sea ice may lead to more life in the sea
Every year an increasing amount of sea ice is melting in the Arctic.
Sea ice extent sinks to record lows at both poles
The Arctic sea ice maximum extent and Antarctic minimum extent are both record lows this year.
When the sea ice melts, juvenile polar cod may go hungry
Polar cod fulfill a key role in the Arctic food web, as they are a major source of food for seals, whales and seabirds alike.
NASA study improves forecasts of summer Arctic sea ice
The Arctic has been losing sea ice over the past several decades as Earth warms.
Melting sea ice may be speeding nature's clock in the Arctic
Spring is coming sooner to some plant species in the low Arctic of Greenland, while other species are delaying their emergence amid warming winters.
Sea ice hit record lows in November
Unusually high air temperatures and a warm ocean have led to a record low Arctic sea ice extent for November, according to scientists at the National Snow and Ice Data Center (NSIDC) at the University of Colorado Boulder.
My contribution to Arctic sea ice melt
Measurements reveal the relationship between individual CO2 emissions and the Arctic's shrinking summer sea ice.
See how Arctic sea ice is losing its bulwark against warming summers
Arctic sea ice, the vast sheath of frozen seawater floating on the Arctic Ocean and its neighboring seas, has been hit with a double whammy over the past decades: as its extent shrunk, the oldest and thickest ice has either thinned or melted away, leaving the sea ice cap more vulnerable to the warming ocean and atmosphere.
Tracking the amount of sea ice from the Greenland ice sheet
The Greenland ice sheet records information about Arctic climate going back more than 120.000 years.
Technique could assess historic changes to Antarctic sea ice and glaciers
Historic changes to Antarctic sea ice could be unravelled using a new technique pioneered by scientists at Plymouth University.

Related Sea Ice Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Jumpstarting Creativity
Our greatest breakthroughs and triumphs have one thing in common: creativity. But how do you ignite it? And how do you rekindle it? This hour, TED speakers explore ideas on jumpstarting creativity. Guests include economist Tim Harford, producer Helen Marriage, artificial intelligence researcher Steve Engels, and behavioral scientist Marily Oppezzo.
Now Playing: Science for the People

#524 The Human Network
What does a network of humans look like and how does it work? How does information spread? How do decisions and opinions spread? What gets distorted as it moves through the network and why? This week we dig into the ins and outs of human networks with Matthew Jackson, Professor of Economics at Stanford University and author of the book "The Human Network: How Your Social Position Determines Your Power, Beliefs, and Behaviours".