Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Glaciers: A window into human impact on the global carbon cycle

20.02.2012
Fossil fuel signature found in Alaskan ice

New clues as to how the Earth's remote ecosystems have been influenced by the industrial revolution are locked, frozen in the ice of glaciers. That is the finding of a group of scientists, including Robert Spencer of the Woods Hole Research Center. The research will be published in the March 2012 issue of Nature Geoscience.

Globally, glacier ice loss is accelerating, driven in part by the deposition of carbon in the form of soot or "black carbon," which darkens glacier surfaces and increases their absorption of light and heat. The burning of biomass – trees, leaves and other vegetation around the globe, often in fires associated with deforestation – and fossil fuel combustion, are the major sources of black carbon.

Spencer and his fellow scientists have conducted much of their research at the Mendenhall Glacier near Juneau, Alaska. Mendenhall and other glaciers that end their journey in the Gulf of Alaska receive a high rate of precipitation, which exacerbates the deposition of soot, but also makes for a good research site.

"We are finding this human derived signature in a corner of the U.S. that is traditionally viewed as being exceptionally pristine," Spencer notes. "The burning of biomass and fossil fuels has an impact we can witness in these glacier systems although they are distant from industrial centers, and it highlights that the surface biogeochemical cycles of today are universally post-industrial in a way we do not fully appreciate."

The key to the process is carbon-containing dissolved organic matter (DOM) in the glacial ice. Glaciers provide a great deal of carbon to downstream ecosystems. Many scientists believe the source of this carbon is the ancient forests and peatlands overrun by the glaciers. However, thanks to new evidence from radiocarbon dating and ultra-high resolution mass spectrometry, Spencer and his colleagues believe that the carbon comes mainly from the burning of fossil fuels and contemporary biomass. Once the organic matter that contains black carbon is deposited on the glacier surface by snow and rain, the resultant DOM moves with the glacier and is eventually delivered downstream in meltwaters where it provides food for microorganisms at the base of the aquatic food web.

"In frigid glacier environments any input stands out, making glaciers ideal sentinel ecosystems for the detection and study of anthropogenic perturbation," said Spencer referring to the reason why glaciers record the impact of human emissions. "However, the deposition of this organic material happens everywhere and in vibrant ecosystems such as those found in temperate or tropical regions, once this organic material makes landfall it is quickly consumed in the general milieu of life." The Mendenhall glacier research site therefore allows a unique perspective for studies such as this one.

Glaciers and ice sheets together represent the second largest reservoir of water on the planet, and glacier ecosystems cover ten percent of the Earth, yet the carbon dynamics underpinning those ecosystems remain poorly understood. "Improving our understanding of glacier biogeochemistry is of great urgency, as glacier environments are among the most sensitive to climate change and the effects of industrial pollution," emphasizes Spencer.

The researchers' findings also reveal how the ocean may have changed over past centuries. The microbes that form the very bottom of the food web are particularly sensitive to changes in the quantity and quality of the carbon entering the marine system. Since the study found that the organic matter in glacier outflows stems largely from human activities, it means that the supply of glacier carbon to the coastal waters of the Gulf of Alaska is a modern, post-industrial phenomenon. "When we look at the marine food webs today, we may be seeing a picture that is significantly different from what existed before the late-18th century," said Aron Stubbins a collaborator from the Skidaway Institute of Oceanography. "It is unknown how this manmade carbon has influenced the coastal food webs of Alaska and the fisheries they support."

A warming climate will increase the outflow of the glaciers and the accompanying input of dissolved organic material into the coastal ocean. This will be most keenly felt in glacially dominated coastal regions, such as those off of the Gulf of Alaska, Greenland and Patagonia. These are the areas that are experiencing the highest levels of glacier ice loss.

Spencer's collaborators on the project included Eran Hood and Andrew Vermilyea from the University of Alaska Southeast; Peter Raymond and David Butman from Yale University; George Aiken, Robert Striegl and Paul Schuster from the U.S. Geological Survey; Rachel Sleighter, Hussain Abdulla and Patrick Hatcher from Old Dominion University; Peter Hernes from the University of California-Davis; Durelle Scott from Virginia Polytechnic Institute and State University; and Aron Stubbins from Skidaway Institute of Oceanography.

Ian Vorster | EurekAlert!
Further information:
http://www.whrc.org

More articles from Earth Sciences:

nachricht By saving cost and energy, the lighting revolution may increase light pollution
23.11.2017 | Helmholtz-Zentrum Potsdam - Deutsches GeoForschungsZentrum GFZ

nachricht Frictional Heat Powers Hydrothermal Activity on Enceladus
23.11.2017 | Universität Heidelberg

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Frictional Heat Powers Hydrothermal Activity on Enceladus

Computer simulation shows how the icy moon heats water in a porous rock core

Heat from the friction of rocks caused by tidal forces could be the “engine” for the hydrothermal activity on Saturn's moon Enceladus. This presupposes that...

Im Focus: Nanoparticles help with malaria diagnosis – new rapid test in development

The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.

Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

Underwater acoustic localization of marine mammals and vehicles

23.11.2017 | Information Technology

Enhancing the quantum sensing capabilities of diamond

23.11.2017 | Physics and Astronomy

Meadows beat out shrubs when it comes to storing carbon

23.11.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>