Biofuels actually add to carbon emissions and so climate change.

The breakthrough in the creation of bio-crude from green waste, developed by the CSIRO and Monash University, discussed in my post of 4th February 2008, seems even more important today.

New research by a number of scientists finds that some agro-biofuels can actually add to greenhouse gas emissions emissions rather than being a source of “saving emissions of fossil fuel derived Co2”. Three pieces of research have been released that challenge the notion that replacing fossil fuels with biofuels is useful in the struggle to arrest climate change.

The first piece of research was reported in the journal Atmospheric Chemistry and Physics on January 29, and looked at the role of the application of fertilisers to biofuels in nitrous oxide N2O release which affects climate and strathospheric ozone chemistry. It concluded that that “biofuel production of commonly used biofuels such as biodiesel from rapeseed and bioethanol from corn (maize), depending on the N fertilizer uptake efficiency by plants, can contribute as much or more to global warming by N2O emissions, than to cooling by fossil fuel saving.” In fact, scientists found that the release from fixed nitrogen application in agro-biofuel production can be “in the the range of 3-5%, 3-5 times larger than assumed in current life cycle analyses, with great importance for climate. ” They concluded that the relatively large emission of N2O exacerbates the already huge challenge of getting global warming under control.

The early research was reported on the Times Online in September, 2007. Professor Keith Smith, a professor at The University of Edinburgh and one of the researchers, remarked at that time, that rational decisions were needed “rather than simply jumping on the bandwagon because superficially something appears to reduce emissions.” The research team was formed of scientists from Britain, the US and Germany, and included Professor Paul Crutzen, who won a Nobel Prize for his work on ozone.

The researchers did indicate however, that crops with less nitrogen demands such as grasses and woody coppice species have more favourable climate impacts. This is obviously good news for the CSIRO team who source their material from green waste such as garden waste, crop residues and forest thinnings.

The other two pieces of research were reported by Jim Giles in the New Scientist, originating from the journal, Science. One analysis by Joseph Fargione
of The Nature Conservancy and his collegues “looked at land that is switched to biofuel crop production. Carbon will be released when forests are felled or bush cleared, and longer-term emissions created by dead roots decaying.” They posited that the “carbon debt” created may take centuries to pay back through switching to biofuels. However, as we have seen in the previously mentioned research, this may take even longer depending on the crop source for the biofuel production if theN2O emissions are also taken into account.

A third study found that the use of land for biofuel crops needed further forestry clearing to replace land for food crops and so created further carbon release, exacerbating greenhouse emissions further. In fact it found the resulting carbon release to be twice as much as for petrol. “The implications of these changes in land use have not been appreciated up until now,” Alex Farrell, at the University of California, Berkeley, US. was quoted as saying.

The location for these two studies is quoted as : Journal reference: Science (DOI:10.1126/science.1152747 and DOI:10.1126/science.1151861)

What this tells us is that the problem is far more complex than imagined. While different countries are subsidising these new technologies and setting transfer targets into the future, they may actually be fostering the increase in greenhouse gas emissions. As ever the need for rigorous science is of utmost importance before embarking haphazardly into untested technologies. Reading the research is recommended for the further detail they contain and the additional considerations and recommendations they propose.


~ by abstraktbiblos on Friday, 8 February, 2008.

One Response to “Biofuels actually add to carbon emissions and so climate change.”

  1. I found your site on technorati and read a few of your other posts. Keep up the good work. I just added your RSS feed to my Google News Reader. Looking forward to reading more from you.

    Tim Ramsey

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