Bio-fuels to save aviation?

One of the more controversial approaches to lowering carbon emissions while dealing with the reality of finite fossil fuel resources is the switch to bio-fuels. While the switch to bio-fuels for cars and farm machinery has been taking place for some years, we are now seeing it hailed as the solution for the aviation industry. Of course the reason the aviation industry is so keen to embrace bio-fuels is that they simply don't have the options that the auto industry has. Electric and hybrid solutions, or anything that involves heavy batteries, is simply never going to...well....fly.

Whenever I bring up bio-fuels in conversation, I am met with one of two strongly opposing views. On the one hand, several people in business have proudly proclaimed to me that they have switched their fleets to bio-diesel, thus significantly reducing their carbon footprints. However, the more common response I get is a negative one based on the idea that 'bio-fuels aren't really low carbon' and/or 'bio-fuels are not sustainable as farmers who were growing/selling their crops for food are now selling them for bio-diesel'.

From my lay person’s perspective, these are the major issues I am aware of related to the uptake of bio-fuels:
1. Effect on food resources
2. Broader environmental impacts of growing new crops
3. Net carbon footprint
4. Financial viability

Let's briefly examine each of these issues.

Effect on food resources
In a world with food shortages and a fast growing population, there is no doubt that this is a major issue of concern. We are struggling to feed the 6.7 billion people on the planet now, and with the population expected to grow to 9.2 billion by 2050 security of food resources is as big an issue as climate change.

However, there are crops suitable for bio-fuels that can be grown in areas that have not previously been considered arable, creating new industry opportunities without affecting food crops. As well as this, there are farmers who have previously been growing crops such as Coca (for cocaine production) who are switching to crops for bio-fuels, however this seems to have as many negatives as positives.

Broader environmental impacts of growing new crops
This is a complex area with many potential impacts.

Land clearing - If the crop is not replacing an existing crop, then is land clearing taking place? What is the effect of this on bio-diversity? How much carbon is released through this clearing? How much carbon was being processed by the existing plant stock? If it is as much or more than that processed by the bio-fuel feedstock then this will result in a negative carbon outcome.

Soil carbon – How much carbon is going to be released from the soil versus that added back into the soil?
Is the feedstock safe to grow in the area? Jatropha curcas is the feedstock proposed by many in the aviation industry, and it has been suggested this could be grown in areas of northern Australia previously not considered arable. But jatropha is currently classed as a noxious weed in this region. What are the possible negative effects of cultivating it? Can it be controlled?

Genetic Modification - The GM industry was quick to release modified crops for the purpose of creating bio-fuel. However, as with all GM modified crops only time will tell what resistance they have to disease and how they cross-breed with non-GM crops. It only takes a genetic disposition to one new disease to be introduced by a modified crop, and for that gene to spread into the broader plant population and you could have an epidemic that effects both fuel and food production.

Water - As with any new crop one must consider how much water is required to grow the crop and where is that coming from? Is there a sustainable water source?

General effect on bio-diversity - Introducing any new crop on a mass scale inevitably has some effect on bio-diversity. Have these been thought through?

Net carbon footprint
Calculating the net carbon impact of switching to bio-fuel is very complex, however we need a reliable standard for doing this if we are to evaluate one feedstock against another. There is no doubt that feed stocks such as corn are not ideal from a carbon perspective, and that much better options exist.

Financial viability
After breaking $150/barrel, oil prices have recently fallen below $40/barrel. The challenge for bio-fuel growers and refiners is to be cost competitive with oil.

The fundamental cost of extracting oil from the earth, combined with its finite availability versus consistent global demand means that the cost will inevitably go up over time. At the same time the costs of producing bio-fuel should reduce as the industry develops and matures. In the short-term government support may be required, however in the longer term market forces will work in the favour of bio-fuels.

So what does the future hold?
Many are hanging their hats on bio-fuel made from algae, and the future of this industry looks promising. While this may well alleviate concerns over food security and land-related environmental issues, farming algae seems like a very new idea. Who knows what other environmental impacts this may have?

Others see the current US corn-based ethanol industry as a stepping stone to something called Cellulosic Biofuel, which looks more sustainable.

Bio-fuels will certainly form part of the solution to our long term energy requirements. For the aviation industry in particular, it appears to be critically important, considering the lack of other viable alternatives. The challenge will be determining how big a role bio-fuels are to play in our broader energy requirements given the larger social and environmental impacts, and how to safely pursue innovation in this area.

Who knows, one day we may be able to step onto a plane without feeling guilty for the massive carbon footprint we are generating.

Okay, I know we have many members far more knowledgeable than me on this topic. Please let me know your thoughts.