Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Large differences in the climate impact of biofuels

16.11.2011
When biomass is combusted the carbon that once was bound in the growing tree is released into the atmosphere.

For this reason, bioenergy is often considered carbon dioxide neutral. Research at the University of Gothenburg, Sweden, however, shows that this is a simplification. The use of bioenergy may affect ecosystem carbon stocks, and it can take anything from 2 to 100 years for different biofuels to achieve carbon dioxide neutrality.

“Using a tree as biofuel creates a carbon dioxide debt that must be “paid back” before the fuel can be considered to be carbon dioxide neutral. Energy forest is fully neutralised after 3-5 years, while other trees grow so slowly that it can take up to 100 years before they achieve carbon dioxide neutrality” says Lars Zetterberg of the Department of Earth Sciences at the University of Gothenburg.

The use of bioenergy affects ecosystem carbon stocks over time in either a positive or negative way. Biofuels where the combustion related emissions are compensated rapidly have a lower climate impact than fuels for which it takes a long time for the emissions to be compensated. Despite this, the difference in climate impacts between slow and rapid biofuels is rarely highlighted in political contexts. Emissions from bioenergy are, for example, not included in countries’ commitments under the Kyoto Protocol.

In his PhD thesis, Lars Zetterberg analyses how different types of biofuels affects the ecosystem carbon stock over time, and the consequent climate impact. The results show that biofuels where the combustion related emissions are compensated rapidly have a lower climate impact than fuels for which it takes a long time for the emissions to be compensated. Results from this study can help decision makers to understand the climate impacts from different bioenergy types in order to prioritize between different bioenergy alternatives.

“The time perspective over which the analysis is done is crucial for the result. Over a 100 year perspective the use of stumps for energy has a significantly lower climate impact than coal, but over a 20 year time perspective, stumps have a higher climate impact than natural gas. Using logging residues in the form of branches and tops for energy reduces carbon dioxide emissions in both the short term and the long term.”

If environmental legislation, for instance the EU renewables directive, requires that climate benefits of biofuels are calculated over a 20 year period, biofuels that need longer time to reach carbon neutrality may be regarded as not renewable..

“If we want to do reduce global carbon emissions quickly, we should prioritize fuels that are beneficial on a short time scale, for instance 20 years In addition, over a longer time scale it will be beneficial to replace coal with stumps, even if we will not see a result until after 20 years.”

In the thesis, Lars Zetterberg also addresses how the EU Emissions Trading System should be designed in order to incentivize the use of carbon dioxide efficient fuels.

The thesis Instruments for Reaching Climate Objectives – Focusing on the Time Aspects of Bioenergy and Allocation Rules in the European Union’s Emissions Trading System was successfully defended at a disputation held in the Department of Earth Sciences at the University of Gothenburg.

For more information, please contact: Lars Zetterberg
Telephone: +46 8 5985 6357
E-mail: lars.zetterberg@ivl.se

Helena Aaberg | idw
Further information:
http://www.gu.se
http://gupea.ub.gu.se/handle/2077/26672

More articles from Ecology, The Environment and Conservation:

nachricht Scientists on the road to discovering impact of urban road dust
18.01.2018 | University of Alberta

nachricht Gran Chaco: Biodiversity at High Risk
17.01.2018 | 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: 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...

Im Focus: Room-temperature multiferroic thin films and their properties

Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.

Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...

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

Let the good tubes roll

19.01.2018 | Materials Sciences

How cancer metastasis happens: Researchers reveal a key mechanism

19.01.2018 | Health and Medicine

Meteoritic stardust unlocks timing of supernova dust formation

19.01.2018 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>