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 Dry landscapes can increase disease transmission
20.06.2018 | Forschungsverbund Berlin e.V.

nachricht 100 % Organic Farming in Bhutan – a Realistic Target?
15.06.2018 | Humboldt-Universität zu Berlin

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: Temperature-controlled fiber-optic light source with liquid core

In a recent publication in the renowned journal Optica, scientists of Leibniz-Institute of Photonic Technology (Leibniz IPHT) in Jena showed that they can accurately control the optical properties of liquid-core fiber lasers and therefore their spectral band width by temperature and pressure tuning.

Already last year, the researchers provided experimental proof of a new dynamic of hybrid solitons– temporally and spectrally stationary light waves resulting...

Im Focus: Overdosing on Calcium

Nano crystals impact stem cell fate during bone formation

Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...

Im Focus: AchemAsia 2019 will take place in Shanghai

Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.

Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...

Im Focus: First real-time test of Li-Fi utilization for the industrial Internet of Things

The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.

Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.

Im Focus: Sharp images with flexible fibers

An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.

Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Munich conference on asteroid detection, tracking and defense

13.06.2018 | Event News

2nd International Baltic Earth Conference in Denmark: “The Baltic Sea region in Transition”

08.06.2018 | Event News

ISEKI_Food 2018: Conference with Holistic View of Food Production

05.06.2018 | Event News

 
Latest News

Graphene assembled film shows higher thermal conductivity than graphite film

22.06.2018 | Materials Sciences

Fast rising bedrock below West Antarctica reveals an extremely fluid Earth mantle

22.06.2018 | Earth Sciences

Zebrafish's near 360 degree UV-vision knocks stripes off Google Street View

22.06.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>