Biofuels green credentials take hit in new study

Biofuels have been seen as a possible way to move over to a more sustainable fuel source, especially for motorised vehicles and large scale energy generation. They are a quick to implement substitute for traditional petroleum and diesel vehicles, which would necessitate fewer infrastructure changes than switching to hydrogen powered or electric vehicles.

Unfortunately their green credentials have taken a big hit, with a new study showing that emissions of nitrous oxide in the growing stage of the process means that they are not significantly more environmentally friendly than traditional fuels, when produced in certain ways. Biofuels have already been criticised for destroying rainforest and other natural habitats, as well as increasing the prices of foods, especially when producing ethanol.

Nitrous Oxides, sometimes known as laughing gas, are a particularly potent greenhouse gas, which molecule for molecule causes 310 times the heat trapping effect that carbon dioxide does. During biofuel production it is created when nitrogen rich fertilisers are added to the soil, in an effort to increase crop yield. This study shows that the amount of nitrous oxide produced per litre of fuel created, is similar in its greenhouse effect to petroleum.

A study by Nobel Prize winner Paul Crutzen found in 2008 that the gasses agricultural emissions had been hugely underestimated and it has also been shown that since pre-industrial times, the concentration of nitrous oxide in the atmosphere has increased by 15 per cent. This is also relevant in relation to ozone depletion; the gas destroys ozone found in the stratosphere.

On the new study highlighting the biofuel nitrous oxide emissions, Professor Lars Bakken with the Nitrogen Group at the University of Life Sciences (UMB) in Norway says, "The end result is more or less zero gain, Nitrous oxide actually tips the balance in the direction of greater warming, undermining the promise of biological fuels as a means to effect cooling." This is worrying considering the huge increase in biofuel investment intended to slow global warming.

In countries looking to intensify their agriculture, there is greater risk of lower soil pH; this prevents bacteria from breaking down nitrous oxide in the soil to more benign nitrogen gas. The researchers believe this will become a growing issue in rapidly developing countries like China and that steps must be taken now to avoid a rapid increase in the emission of the gas. The production of biofuels will only add to this problem it seems.

These new developments in our understanding of biofuels are worrying, but the premise that biofuels can help move us away from fossil fuels still struggles on. Perhaps with a slightly different approach to producing the fuel, there is still some hope that it can still offer something to the future energy mix