Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Widespread Arctic warming crosses critical ecological thresholds, scientists warn

01.03.2005


New international study suggests effects of climate change may be irreversible



Unprecedented and maybe irreversible effects of Arctic warming, linked to human intervention, have been discovered by a team of international researchers led by Queen’s University biologist John Smol and University of Alberta earth scientist Alexander Wolfe.
The researchers have found dramatic new evidence of changes in the community composition of freshwater algae, water fleas and insect larvae (the base of most aquatic food webs) in a large new study that covers five circumpolar countries extending halfway around the world and 30 degrees of latitude spanning boreal forest to high arctic tundra ecosystems.

"This is an important compilation of data that human interference is affecting ecosystems on a profound scale," says Dr. Smol, Canada Research Chair in Environmental Change and 2004 winner of Canada’s top science award, the Gerhard Herzberg Gold Medal. "We’re crossing ecological thresholds here, as shown by changes in biota associated with climate-related phenomena like receding ice cover in lakes. Once you pass these thresholds it’s hard to go back."



The team’s findings, in the largest study of its kind, will be published the week of February 28 in the Proceedings of the National Academy of Sciences (PNAS).

A total of 26 researchers from Canada, Finland, Norway, the UK, and Russia have produced 55 historical profiles of algal and invertebrate animal remains from the sediment in 46 Arctic lakes. Also on the team from Queen’s are biologist Kathleen Rûhland and PhD student Bronwyn Keatley. John Birks, a professor at the University of Bergen and adjunct professor at Queen’s, quantified the amount of biological change using statistical approaches.

The new study shows that climate change has lengthened summers and reduced lake ice cover across much of the Arctic. This in turn prolongs the growing season available to highly sensitive lake organisms, and opens up new habitats. The most intense population changes occurred in the northernmost study sites, where the greatest amount of warming appears to have taken place, the researchers say.

"Polar regions are expected to show the first signs of climatic warming, and are therefore considered sentinels of environmental change," says Dr. Wolfe. "Unfortunately, long-term monitoring data are generally lacking in these areas, which makes it difficult to determine the direction and magnitude of past environmental changes." Since lakes are ubiquitous to most Arctic environments, however, microfossils of aquatic organisms preserved in the sediment become an archive of the lake’s history, adds University of Toronto Geology Professor Marianne Douglas.

"The timing of the changes is certainly consistent with human interference, and one of the major avenues is through climate warning," notes Queen’s biologist Dr. Kathleen Rûhland. "This is another example of how humans are directly and indirectly affecting global ecology."

An earlier lake sediment study co-authored by Drs. Douglas and Smol, published in the journal Science in 1994, caused controversy with its interpretation of climatic warming in three high Arctic ponds. Now, says Dr. Smol, "the tide has turned, and some of the strongest skeptics of that 1994 study are co-authors on this paper."

One area in the Canadian sub-Arctic that appears not to be warming to the same extent is in Labrador and northern Québec. Team member Reinhard Pienitz, from Université Laval, notes that this represents an important control region for the study. The fact that no patterns of biological change are evident there supports the findings from other areas where warming has been inferred. "The changes have not been primarily caused by, for example, atmospheric deposition of contaminants," says Dr. Pienitz.

The study concludes that it may soon be impossible to find "pristine Arctic environments untouched by climate warming." And since changes in the Arctic are considered bellwethers of what is to come further south, the researchers consider this their most urgent environmental wake-up call to date.

"If you look at one lake at a time, you still get important information, but it’s hard to make large-scale, regional assessments," says Dr. Smol. He compares this to viewing an Impressionist painting, where looking at one small section may only reveal dots, but on stepping back you see the whole picture. "Once you compile the larger dataset of all these lakes and ponds, striking and consistent patterns become evident. Taken together, it’s a very powerful message."

Nancy Dorrance | EurekAlert!
Further information:
http://www.queensu.ca
http://biology.queensu.ca/~pearl/press_releases.htm

More articles from Ecology, The Environment and Conservation:

nachricht Upcycling 'fast fashion' to reduce waste and pollution
03.04.2017 | American Chemical Society

nachricht Litter is present throughout the world’s oceans: 1,220 species affected
27.03.2017 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

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

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

Scientist invents way to trigger artificial photosynthesis to clean air

26.04.2017 | Materials Sciences

Ammonium nitrogen input increases the synthesis of anticarcinogenic compounds in broccoli

26.04.2017 | Agricultural and Forestry Science

SwRI-led team discovers lull in Mars' giant impact history

26.04.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>