Tuesday 8 November 2011

So what does the literature say??


Afternoon! After reading that article yesterday I thought there couldn’t be a more appropriate time to blog about a few interesting journals that I have come across over the last month surrounding carbon budgets.

I think it would be fair to say that we are living in a world today, where organisation’s through to individuals are experiencing increasing pressure to curb greenhouse gas emissions, as a result of the accelerating risks posed by climate change. The need for greener, cleaner energy couldn’t be greater, with many people turning to biofuels as the answer. But is it really ‘green’ energy or are we actually sending ourselves further into the red??

Much of the academic field agree that the answer to this question is not straightforward, being highly dependant on the location of the plantation. This concept was touched upon in the summary table below, highlighting the potential for increased carbon dioxide emissions through loss of biomass, slash and burn techniques and draining peatlands. A study by Fargione et al. (2008) addressed in greater depth the so called ‘Biofuel Carbon Debt’ that is generated as a result of the concentration of CO2 released during the first 50 years after land conversion has occurred to create plantations. Emphasis is placed on the release of carbon from the two largest biologically active stores of terrestrial carbon: soils and plant biomass.


The graph highlights the impacts that exposed soils and foregone plant biomass has on the carbon budget, concisely and clearly displaying the time taken to repay the carbon debt in various geographical locations. In regard to the specific focus of this blog, I feel it important to stress the figures related to palm oil plantations in Southeast Asia. According to Fargione et al. (2008) converting tropical rainforest to palm oil plantations would lead to a carbon debt of ~610 Mg of CO2 ha-1 that would take circa 86 years to repay! However if that isn’t shocking enough from a crop that is supposedly carbon neutral and the future of energy markets, let me draw your attention to the disastrous consequences of converting peatlands. It takes a palm oil plantation located on a previous peatland area, approximately 420 years to repay one hefty carbon debt! Seeing as the study goes on state that 27% of new palm oil plantation are being located on tropical peatlands, the future is bleak for Southeast Asia to supply a greener energy solution.  

Other recent works by the likes of Gibbs et al. (2008) and Danielsen et al. (2008) concur with the conclusion drawn by Fargione et al. (2008) that biofuel expansion into natural tropical ecosystems will lead to net carbon emissions for decades to centuries. However despite the underlying conclusion being the same, there is discrepancy in the figures and focus in both the articles. Gibbs et al. (2008) paper predicts the carbon debt derived from plantations situated on previous peatlands to be more than double than that stated by Fargione et al. (2008), taking a supposed 900 years to repay! The study also addresses the potential benefits of forming plantations on degraded agricultural lands, thats productivity in regard to food crops has fallen, highlighting that within under two decades carbon sequestered in plant biomass and the concentration of carbon saved through the use of the biofuel would be outweigh the carbon released during its production. The article brings to light that if marginalized land can be found and ultilised it could reduce the implementation costs of establishing biofuel production and therefore allow population to reap the benefits more rapidly. However rather grimly states that even with modifications to the biofuel industry, technological advances of feedstocks provoking a doubling in ethanol yield from the most productive feedstock; sugarcane, more than three decades would be required to replace lost rainforest carbon.

The study by Danielsen et al. (2008) also looks to the future with close examination of the impacts on biodiversity, in addition to climate. It states the huge importance of tropical rainforests for endangered and rare species as well as its significance as a store of around 46% of world terrestrial carbon. Current deforestation is accordingly accounting for 25% of total net carbon emissions. The paper puts emphasis on the fact that as countries strive to meet obligations to reduce carbon emissions under one international agreement (Kyoto Protocol), they may not only fail to meet their obligations under another (Convention on Biological Diversity) but may actually hasten global change.

This provides some food for thought surrounding the complexities of ultilising palm oil as a suitable biofuel today and into the future.

2 comments:

  1. Heya Gem! I know that the environmental implications of deforestation for plam oil are huge, but do you know what its' potential extent of cultivation on degraded lands etc is? i.e. how credible is sustainable production?

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  2. Hey Yulia!

    I hope you had a fantastic christmas and new year! I must firstly apologise for such a late response, somehow whilst checking through my blog I did not see that I had received a comment for yourself. Please forgive me!

    In regard to your question, personally I feel that if all the right measures are taken, i.e. utilising old agricultural land, reducing the emissions of the transportation vehicles etc. are implemented the palm oil industry could potentially become a sustainable industry. However, I do feel that its not just on the supply side that attitudes and practises need to be addressed, with consumers demanding the move towards sustainability. My later posts mention the Roundtable on Sustainable Palm Oil and the work it has and will achieve in the future.

    One thing I will say is that I truly believe that the transition to becoming a sustainable industry is one that will take a long time and a process consisting on many small steps to reach the final goal.

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