Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

The natural greenhouse gas sink is smaller than believed

10.01.2011
An international team of scientists has uncovered an important part of the global greenhouse gas budget. This new analysis indicates that greenhouse gas uptake by continents is less optimistic than previously thought. The balance between carbon uptake by continents and their emissions of greenhouse gases is important because it indicates how much continents can compensate for human emissions of CO2 to the atmosphere.

Past analyses of carbon and greenhouse gas exchanges on continents have failed to account for the influence of lakes, impoundments, and running water. This study, published in the journal Science, shows that natural release of the potent greenhouse gas methane from inland waters may be far greater than previously known. By difference, the net absorption of greenhouse gases by natural land environments, such as forests, may therefore be at least 25 % smaller than thought.

This is the conclusion of a study by David Bastviken, Linköping University, Lars Tranvik, Uppsala University, John Downing, Iowa State University, Patrick Crill, Stockholm University, and Alex Enrich-Prast, University Federal of Rio de Janeiro.

The increased greenhouse effect is caused by human emissions of greenhouse gases. Some ecosystems, such as forests can absorb carbon dioxide and act as greenhouse gas sinks, which is important for the greenhouse gas balance and the climate. The role of freshwater environments, integrated into continental environments, has been unclear because of underestimates of the amount of continental water and a shortage of data on greenhouse gas emissions.

Methane emissions from lakes and running water occur naturally and should not be considered an environmental threat. These gas emissions have, however, been difficult to assess and are poorly understood.

- Small methane emissions from the surfaces of water bodies occur continuously, says David Bastviken, but much greater emissions occur suddenly, and with irregular timing, when methane bubbles from the sediment reach the atmosphere. Such fluxes have been difficult to measure.

The authors have summarized methane fluxes from 474 freshwater environments. They have also used updated estimates of the global area of inland waters. Based on these data, they estimated that methane emissions from the freshwaters of the world counter-balance 25 percent of the carbon dioxide absorbed by natural land environments. The large effect of aquatic methane emission is due to the large quantity of gas emission and the stronger greenhouse effect produced by methane molecules compared to carbon dioxide. One implication of this new accounting is that the greenhouse gas sink provided by forests and other land ecosystems is substantially smaller than hitherto believed.

The terrestrial sink may even be lower than we have calculated, says David Bastviken. Because it is difficult to measure methane bubble fluxes and the global area of freshwaters may still be underestimated, we have probably underestimated the methane emissions.

If we do not properly account for natural greenhouse gas sinks and emissions, we may misunderstand the urgency of reducing anthropogenic emissions.

A smaller continental greenhouse gas sink means that the capacity of natural systems to absorb greenhouse gases is very valuable.

- We have to take great care of the remaining forests and other natural greenhouse gas sinks, because we have already reduced their area through deforestation and other land conversions, David says. An accurate accounting of all components of the continental greenhouse gas budget, including the role of inland waters, will help us evaluate the greenhouse gas uptake by land ecosystems in relation to society’s greenhouse gas emissions.

Freshwater Methane Emissions Offset the Continental Carbon Sink
David Bastviken, Lars J. Tranvik, John A. Downing, Patrick M. Crill, Alex Enrich-Prast, Science 7 January 2011: 50. [DOI:10.1126/science.1196808]
Telephone to David Bastviken +46-73 4144970, e-mail david.bastviken@liu.se
Lars Tranvik +46 -73 322 58 30, e-mail lars.tranvik@ebc.uu.se
Pressofficer Åke Hjelm; åke.hjelm@liu.se;+46-13 28 13 95

Åke Hjelm | idw
Further information:
http://www.vr.se
http://www.sciencemag.org/search?site_area=sci&y=17&fulltext=David%20Bastviken&x=29&submit=yes

More articles from Ecology, The Environment and Conservation:

nachricht How does the loss of species alter ecosystems?
18.05.2017 | Deutsches Zentrum für integrative Biodiversitätsforschung (iDiv) Halle-Jena-Leipzig

nachricht Excess diesel emissions bring global health & environmental impacts
16.05.2017 | International Institute for Applied Systems Analysis (IIASA)

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: Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?

Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.

Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

How herpesviruses win the footrace against the immune system

26.05.2017 | Life Sciences

Water forms 'spine of hydration' around DNA, group finds

26.05.2017 | Life Sciences

First Juno science results supported by University of Leicester's Jupiter 'forecast'

26.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>