Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Arctic sea ice decline may trigger climate change cascade

16.03.2007
Arctic sea ice that has been dwindling for several decades may have reached a tipping point that could trigger a cascade of climate change reaching into Earth's temperate regions, says a new University of Colorado at Boulder study.

Mark Serreze, a senior research scientist at CU-Boulder's National Snow and Ice Data Center who led the study synthesizing results from recent research, said the Arctic sea-ice extent trend has been negative in every month since 1979, when concerted satellite record keeping efforts began. The team attributed the loss of ice, about 38,000 square miles annually as measured each September, to rising concentrations of greenhouse gases and strong natural variability in Arctic sea ice.

"When the ice thins to a vulnerable state, the bottom will drop out and we may quickly move into a new, seasonally ice-free state of the Arctic," Serreze said. "I think there is some evidence that we may have reached that tipping point, and the impacts will not be confined to the Arctic region."

A review paper by Serreze and Julienne Stroeve of CU-Boulder's NSIDC and Marika Holland of the National Center for Atmospheric Research titled "Perspectives on the Arctic's Shrinking Sea Ice Cover" appears in the March 16 issue of Science.

The loss of Arctic sea ice is most often tied to negative effects on wildlife like polar bears and increasing erosion of coastlines in Alaska and Siberia, he said. But other studies have linked Arctic sea ice loss to changes in atmospheric patterns that cause reduced rainfall in the American West or increased precipitation over western and southern Europe, he said.

The decline in Arctic sea ice could impact western states like Colorado, for example, by reducing the severity of Arctic cold fronts dropping into the West and reducing snowfall, impacting the ski industry and agriculture, he said. "Just how things will pan out is unclear, but the bottom line is that Arctic sea ice matters globally," Serreze said.

Because temperatures across the Arctic have risen from 2 degrees to 7 degrees F. in recent decades due to a build-up of atmospheric greenhouse gases, there is no end in sight to the decline in Arctic sea ice extent, said Serreze of CU-Boulder's Cooperative Institute for Research in Environmental Sciences. Arctic sea ice extent is defined as the total area of all regions where ice covers at least 15 percent of the ocean surface.

"While the Arctic is losing a great deal of ice in the summer months, it now seems that it also is regenerating less ice in the winter," said Serreze. "With this increasing vulnerability, a kick to the system just from natural climate fluctuations could send it into a tailspin."

In the late 1980s and early 1990s, shifting wind patterns from the North Atlantic Oscillation flushed much of the thick sea ice out of the Arctic Ocean and into the North Atlantic where it drifted south and eventually melted, he said. The thinner layer of "young" ice that formed it its place melts out more readily in the succeeding summers, leading to more open water and more solar radiation being absorbed by the open ocean and fostering a cycle of higher temperatures and earlier ice melt, he said.

"This ice-flushing event could be a small-scale analog of the sort of kick that could invoke rapid collapse, or it could have been the kick itself," he said. "At this point, I don't think we really know."

Researchers also have seen pulses of warmer water from the North Atlantic entering the Arctic Ocean beginning in the mid-1990s, which promote ice melt and discourage ice growth along the Atlantic ice margin, he said. "This is another one of those potential kicks to the system that could evoke rapid ice decline and send the Arctic into a new state."

The potential for such rapid ice loss was highlighted in a December 2006 study by Holland and her colleagues published in Geophysical Research Letters. In one of their climate model simulations, the Arctic Ocean in September became nearly ice-free between 2040 and 2050.

"Given the growing agreement between models and observations, a transition to a seasonally ice-free Arctic Ocean as the system warms seems increasingly certain," the researchers wrote in Science. "The unresolved questions regard when this new Arctic state will be realized, how rapid the transition will be, and what will be the impacts of this new state on the Arctic and the rest of the globe."

Mark Serreze | EurekAlert!
Further information:
http://www.colorado.edu

More articles from Earth Sciences:

nachricht New Study Will Help Find the Best Locations for Thermal Power Stations in Iceland
19.01.2017 | University of Gothenburg

nachricht Water - as the underlying driver of the Earth’s carbon cycle
17.01.2017 | Max-Planck-Institut für Biogeochemie

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Helmholtz International Fellow Award for Sarah Amalia Teichmann

20.01.2017 | Awards Funding

An innovative high-performance material: biofibers made from green lacewing silk

20.01.2017 | Materials Sciences

Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery

20.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>