A recent article in ‘Science’ from a team of researchers states that planting trees is a better solution to curbing carbon emissions than growing feedstock for bio fuels.

The article goes on to argue that the amount of CO2 sequestered (by forests) over a 30 year period is considerably greater than the amount of emissions avoided by using bio fuels.  This leads them to the conclusion that the EU bio fuel target of ensuring 10% of petrol and diesel comes from renewable sources by 2020 is not an effective way to curb carbon emissions. 

This appears to take a very narrow view of the renewable transport fuel obligation and completely ignores the benefits that bio fuels bring, not only to emissions reduction but also to ensuring a fuel source for cars and trucks once fossil fuel begins to run out.

Fossil fuels have a finite life and it is clear that simply planting trees will not provide a long term solution to our energy needs.  Encouraging the development of bio fuels today, even using first generation feedstock, allows investment in the industry and this allows research and development into the next generation of feedstock that will be able to sidestep issues such as food versus fuel and tax rebates.

No doubt more CO2 can be saved by planting trees than by growing feedstock for bio fuels but there is more at stake than just a straight scientific comparison.  Lignocellulosic materials and oil from algae are two opportunities to develop new sources of energy that could benefit mankind through to and beyond the year 3000.  Planting trees and waiting for them to become fossil fuels will take considerably longer!

Reports in the press last month have indicated that reserves of grain are at a long time low. In the US corn inventories are down to 40 days versus a ten year average of 88. In the EU stocks of barley, wheat and maize are all heavily depleted. The question raised in the press is whether bio fuel is the reason. In the US undoubtedly the dramatic increase in bio ethanol production will have affected grain stocks but in Europe this is less likely to be the case. Nearly 10 million tonnes of barley, wheat and maize have disappeared from European silos in the last few years. Only a small part of this will have been converted to bio ethanol, the Rabobank forecast for bio ethanol production in Europe in 2005 identified just 0.9 million tonnes.

Currently, the EU’s set aside policy results in some 10% of arable farmland being left fallow to avoid surpluses building up within the community. While there are strict rules as to what can be grown on this land, cereal and oilseed crops can be grown against a specific contract for use as feedstock for bio fuels. At this point the food versus fuel debate no longer applies. In the UK there is some 644,000 hectares of set aside land. Assuming it was all used for rapeseed production (and with rapeseed providing roughly 1.2 tonnes of oil per hectare), this would generate 772,800 tonnes of oil, enough to cover the UK’s forecast bio diesel needs for 2008!