Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Deep in Arctic Mud, Geologists Find Strong Evidence of Climate Change

23.01.2007
How severe will global warming get?

Jason P. Briner is looking for an answer buried deep in mud dozens of feet below the surface of lakes in the frigid Canadian Arctic.

His group is gathering the first quantitative temperature data over the last millennium from areas in extreme northeastern sections of the Canadian Arctic, such as Baffin Island.

Every spring, Briner, Ph.D., assistant professor of geology in the College of Arts and Sciences at the University at Buffalo, travels to the region to sample Arctic lake sediments and glaciers and analyzes them to reconstruct past climates.

"As paleoclimatologists, we want to study Earth under conditions similar to those we have today, what we call 'climate analogues,' which might tell us what to expect in the future," he said.

The Arctic as a region is an excellent harbinger of future change, Briner said, because the signals or clues that signify climate change are so much stronger in the Arctic than elsewhere on the planet.

"Yet, even when we take that phenomenon into account," he noted, "the signals we're finding on Baffin Island are huge," he said. "The temperature records, that is, the 'signal' of warmth that we're reconstructing for this part of the Canadian Arctic over the past 10,000 years seems to be higher than the global average for that period and even higher than the Arctic average."

For example, during the 'Holocene thermal maximum,' the warmest period of the past 10,000 years, the Arctic average temperature was two to three degrees warmer than it is today, while the global average was only a degree or so warmer.

"But based on lake sediments from Baffin Island, our data show that this area of the Arctic experienced temperatures five degrees warmer than today," said Briner.

Briner and his co-authors published these results last May in Quaternary Research (Vol. 65, pp. 431-442). The co-authors were N. Michelutti, formerly of the University of Alberta; D.R. Francis of the University of Massachusetts; G.H. Miller of the University of Colorado; Yarrow Axford, Briner's post-doctoral research associate at UB; M.J. Wooller of the University of Alaska, Fairbanks; and A.P. Wolfe of the University of Alberta.

Because Arctic regions show such strong seasonality, Briner explained, it's relatively easy to correlate climate changes with very fine layers in the sediments. In some lakes, each layer represents one year, with thicker sediment layers generally signaling warmer summers.

Like other paleoclimatologists, he also is finding that the warming trend that began in the 20th century is more pronounced in the Arctic than it is in the rest of the globe.

"The magnitude of warmth over the past 100 years seems pretty exceptional in the context of the past 1,000 years," he said.

"Whereas maybe an average of all of the instrument data from the globe shows just a half a degree increase in this century, in the Arctic, temperatures went up by two to three degrees in the same period."

The rapidity of the change also is exceptional, he added.

"If we look at the temperature graphs that we've generated for the past 1,000 years for this region, the temperatures wiggle back and forth, so there is a little variability in there," he said. "However, in the past 100 years, both the magnitude and the rate of temperature increase exceed all the variations of the past 1,000 years."

To do the research, Briner and his graduate students and post-doctoral associates travel to Baffin Island and other areas in extreme northeast Canada each May, while it is still winter there.

They fly to remote Eskimo villages, and then drive snowmobiles, dragging their gear behind them on sleds, for hours across the tundra and sea ice. Once they reach a good sampling site, they set up camp nearby and get to work, drilling through the ice and the water below until their equipment reaches sediments.

"The beauty of lake sediments is that they're being deposited continuously right up until yesterday," Briner said, "so by looking at them, we get clues into past climates, which we can then overlap with records from weather stations, which only cover the past 50 to 75 years."

They then send their samples -- long tubes full of mud -- back to UB, where Briner and his team analyze them.

Among the clues in the cores are isotopes, fossils and increases in organic material from the accumulation of dead organisms and algae.

"Generally, the more organic matter in sediments, the warmer the climate," said Briner.

A primary goal of the research is to account for spatial variability when reconstructing past climate records.

"Everyone knows the climate is extremely variable, spatially," said Briner. "For example, earlier this year, Colorado got slammed with snow and Buffalo didn't get a flake. It's the same when we reconstruct past climates: maybe the climate cooled by 30 degrees in Greenland but only 10 degrees in the area that's now Buffalo."

Reconstructing this spatial variability will help develop a more precise view of how past changes in climate have affected the planet, Briner says, providing a guide for how the current global warming trend may unfold.

"We can use these patterns to test climate models," said Briner. "Once models can adequately predict past climates and their spatial patterns, then we have confidence that they work and so can be used to predict the future."

Briner and members of his team will present some of their data May 2-5 at the 37th Annual International Arctic Workshop in Iceland.

The research is funded by the National Science Foundation.

The University at Buffalo is a premier research-intensive public university, the largest and most comprehensive campus in the State University of New York.

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

More articles from Earth Sciences:

nachricht Seabed mining could destroy ecosystems
23.01.2018 | University of Exeter

nachricht How climate change weakens coral 'immune systems'
23.01.2018 | Ohio State University

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Optical Nanoscope Allows Imaging of Quantum Dots

Physicists have developed a technique based on optical microscopy that can be used to create images of atoms on the nanoscale. In particular, the new method allows the imaging of quantum dots in a semiconductor chip. Together with colleagues from the University of Bochum, scientists from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute reported the findings in the journal Nature Photonics.

Microscopes allow us to see structures that are otherwise invisible to the human eye. However, conventional optical microscopes cannot be used to image...

Im Focus: Artificial agent designs quantum experiments

On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.

We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...

Im Focus: Scientists decipher key principle behind reaction of metalloenzymes

So-called pre-distorted states accelerate photochemical reactions too

What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...

Im Focus: The first precise measurement of a single molecule's effective charge

For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.

Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...

Im Focus: Paradigm shift in Paris: Encouraging an holistic view of laser machining

At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.

No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

10th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Münster, 10-11 April 2018

08.01.2018 | Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

 
Latest News

Rutgers scientists discover 'Legos of life'

23.01.2018 | Life Sciences

Seabed mining could destroy ecosystems

23.01.2018 | Earth Sciences

Transportable laser

23.01.2018 | Physics and Astronomy

VideoLinks Science & Research
Overview of more VideoLinks >>>