Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Arctic Sediments Show That 20th Century Warming Is Unlike Natural Variation

26.10.2009
PNAS paper indicates that changes since the middle of the 20th century are unprecedented

The possibility that climate change might simply be a natural variation like others that have occurred throughout geologic time is dimming, according to evidence in a Proceedings of the National Academy of Sciences paper published today.

The research reveals that sediments retrieved by University at Buffalo geologists from a remote Arctic lake are unlike those seen during previous warming episodes.

The UB researchers and their international colleagues were able to pinpoint that dramatic changes began occurring in unprecedented ways after the midpoint of the twentieth century.

"The sediments from the mid-20th century were not all that different from previous warming intervals," said Jason P. Briner, PhD, assistant professor of geology in the UB College of Arts and Sciences. "But after that things really changed. And the change is unprecedented."

The sediments are considered unique because they contain rare paleoclimate information about the past 200,000 years, providing a far longer record than most other sediments in the glaciated portion of the Arctic, which only reveals clues to the past 10,000 years.

"Since much of the Arctic was covered by big ice sheets during the Ice Age, with the most recent glaciations ending around 10,000 years ago, the lake sediment cores people get there only cover the past 10,000 years," said Briner.

"What is unique about these sediment cores is that even though glaciers covered this lake, for various reasons they did not erode it," said Briner, who discovered the lake in the Canadian Arctic while working on his doctoral dissertation. "The result is that we have a really long sequence or archive of sediment that has survived arctic glaciations, and the data it contains is exceptional."

Working with Briner and colleagues at UB who retrieved and analyzed the sediments, the paper's co-authors at the University of Colorado and Queens University, experts in analyzing fossils of bugs and algae, have pooled their expertise to develop the most comprehensive picture to date of how warming variations throughout the past 200,000 years have altered the lake's ecology.

"There are periods of time reflected in this sediment core that demonstrate that the climate was as warm as today," said Briner, "but that was due to natural causes, having to do with well-understood patterns of the Earth's orbit around the sun. The whole ecosystem has now shifted and the ecosystem we see during just the last few decades is different from those seen during any of the past warm intervals."

Yarrow Axford, a research associate at the University of Colorado, and the paper's lead author, noted: "The 20th century is the only period during the past 200 millennia in which aquatic indicators reflect increased warming, despite the declining effect of slow changes in the tilt of the Earth's axis which, under natural conditions, would lead to climatic cooling."

Co-authors with Briner and Axford are Colin A. Cooke and Alexander P. Wolfe of the University of Alberta; Donna R. Francis of the University of Massachusetts; John P. Smol, Cheryl R. Wilson and Neal Michelutti at Queens University; Gifford H. Miller of the University of Colorado and Elizabeth K. Thomas, who did this work at UB for her master's degree in geology.

The University at Buffalo is a premier research-intensive public university, a flagship institution in the State University of New York system and its largest and most comprehensive campus. UB's more than 28,000 students pursue their academic interests through more than 300 undergraduate, graduate and professional degree programs. Founded in 1846, the University at Buffalo is a member of the Association of American Universities.

Ellen Goldbaum | EurekAlert!
Further information:
http://www.buffalo.edu

More articles from Earth Sciences:

nachricht NASA eyes Pineapple Express soaking California
24.02.2017 | NASA/Goddard Space Flight Center

nachricht 'Quartz' crystals at the Earth's core power its magnetic field
23.02.2017 | Tokyo Institute of Technology

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Stingless bees have their nests protected by soldiers

24.02.2017 | Life Sciences

New risk factors for anxiety disorders

24.02.2017 | Life Sciences

MWC 2017: 5G Capital Berlin

24.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>