Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

For biofuels and climate, location matters

12.05.2015

Dedicating more land to biofuel production can lead to increased greenhouse gas emissions, which take decades to make up for. A new study shows that geography is a key factor determining how big that impact is.

A new study published in the journal Nature Climate Change shows that, when looking at the production site alone, growing biofuel crops can have a significant impact on climate depending on location and crop type. The study is the first geographically explicit life cycle assessment to consider the full range of greenhouse gases emissions from vegetation and soil carbon stock to nitrogen fertilizer emissions in all locations in the world.


Greenhouse gas payback times for corn-based bioethanol in intensively farmed crop locations, (where fertilizers and irrigation are used).

Elshout et al, 2015. Nature Climate Change


Greenhouse gas payback times for corn-based bioethanol, in extensively farmed crop location, (where fertilizers and irrigation are not used).

Elshout et al, 2015. Nature Climate Change

In the last couple of years, research has begun to raise questions about the sustainability of biofuels. Life cycle assessments—a method that calculates the environmental impact of a product through its entire production and use cycle—have returned uncertain results on biofuels, and new research has also begun to consider carbon emissions caused by land use change.

“When you convert wetlands or forests for biofuel production you lose a major carbon sink, so even if you are saving emissions by reducing fossil fuel use, in the short term you are increasing total emissions,” says IIASA Ecosystems Services and Management Program Director Michael Obersteiner, who co-authored the study along with researchers from IIASA, Radboud University in the Netherlands, and other partners.

In the long term, natural ecosystems such as forests and grasslands sequester carbon from the atmosphere and store it in vegetation and soils. While crops also absorb carbon from the atmosphere, they do not build carbon storage, and unsustainable agricultural practices can also lead to erosion and run-off that further degrades the carbon storage capability of soils.

The new study provides a method of accounting and evaluating biofuels based on a field-level high resolution greenhouse gas accounting. It calculates the time it would take, on a specific piece of land, for biofuel production to make up for the emissions it generates by converting from what was there prior to biofuel production. The researchers call this measure “greenhouse gas payback time.”

The study was led by Radboud University PhD candidate Pieter Elshout. He says, “Our model is the first that offers a global, spatially-explicit overview of biogenic gas emission resulting from crops used to produce biofuels. In developing this model, our calculations of the durations of payback times took account of the entire production chain for fossil fuels and biofuels with the accompanying greenhouse emissions.”

They find that the payback time varies widely around the world depending on the current land use of the specific location, crop type, and cultivation method. The most important factor was the location, according to the study, accounting for 90% of the variation on payback time.

“This study shows that geography is really the number one factor influencing the direct climate impact of biofuel production. We need to have more precise measurements of what is currently happening on a piece of land when evaluating the direct effects on biogenic carbon emissions of biofuels to be grown there,” says Obersteiner.

The researchers found that current land use and crop type played a big role in the payback time. When grown with no input (such as irrigation or fertilizer), rapeseed is found to have the lowest direct impact, with an average payback time around 20 years, and sugarcane the longest, with a global median of 60 years. When it comes to intensive agriculture, however, payback times systematically decrease for all crop types. The most efficient feedstocks appear to be cereals, such as winter wheat and corn, with payback times lower than 10 years.

While this study unearthed the value of high resolution information for the assessment of biofuels impacts, a broader sustainability perspective on agricultural products emissions remains indispensable, say the researchers. Previous IIASA research has shown that sustainability criteria limited to biofuels could prove inefficient by ignoring other agricultural uses and consumption changes in other parts of the world. [http://www.iiasa.ac.at/publication/more_XJ-13-089.php]

In addition, indirect land use change impacts can change the overall emission balance of biofuels, by displacing other crop production, through trade and demand responses.

IIASA is preparing a complementary study [http://www.iiasa.ac.at/web/home/research/researchPrograms/EcosystemsServicesandM...] on this matter, expected to be published this summer. It looks at a large range of crop-based but also advanced biofuels, using cereal straw or short rotation coppice.

“Today’s paper confirms that standard life cycle assessment approaches, by ignoring geography, have overly simplified biofuel greenhouse gas assessment. Bringing in the full agricultural system responses with indirect land use change could lead to even more nuanced insights on the final environmental merit of the different biofuel feedstocks,” says Hugo Valin, one of the lead authors of the ongoing study.

Reference
Elshout PMF, et. al. 2015. Greenhouse-gas payback times for crop-based biofuels. Nature Climate Change. doi:10.1038/NCLIMATE2642

Contacts
Pieter Elshout
+31 (0)24 365 2060
p.elshout@science.ru.nl

Michael Obersteiner
Program Director
Ecosystems Services and Management
+43(0) 2236 807 460
oberstei@iiasa.ac.at

Katherine Leitzell | idw - Informationsdienst Wissenschaft
Further information:
http://www.iiasa.ac.at

More articles from Earth Sciences:

nachricht Climate satellite: Tracking methane with robust laser technology
22.06.2017 | Fraunhofer-Gesellschaft

nachricht How reliable are shells as climate archives?
21.06.2017 | Leibniz-Zentrum für Marine Tropenforschung (ZMT)

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

Im Focus: Optoelectronic Inline Measurement – Accurate to the Nanometer

Germany counts high-precision manufacturing processes among its advantages as a location. It’s not just the aerospace and automotive industries that require almost waste-free, high-precision manufacturing to provide an efficient way of testing the shape and orientation tolerances of products. Since current inline measurement technology not yet provides the required accuracy, the Fraunhofer Institute for Laser Technology ILT is collaborating with four renowned industry partners in the INSPIRE project to develop inline sensors with a new accuracy class. Funded by the German Federal Ministry of Education and Research (BMBF), the project is scheduled to run until the end of 2019.

New Manufacturing Technologies for New Products

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

A new technique isolates neuronal activity during memory consolidation

22.06.2017 | Life Sciences

Plant inspiration could lead to flexible electronics

22.06.2017 | Materials Sciences

A rhodium-based catalyst for making organosilicon using less precious metal

22.06.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>