photo: Will Luo/Creative Commons
For anyone that's paid attention to the world of biofuels, specifically the impact that land-use changes and cultivation method can have on lifecycle greenhouse gas emissions, this won't come as a shock: New research in Environmental Science and Technology shows that in extreme cases burning fossil fuels in airplanes may be the greener choice than biofuels. Report lead author James Hileman of MIT correctly notes,
You can't simply say a biofuel is good or bad. It depends on how it's produced and processed. Severe cases of land use change could make coal-to-liquid fuels look green. (Science Daily)
Hileman notes that coal-to-liquids fuels are not a green option either, however.
Those cases of severe land use change? Looking at palm oil, Hileman's team's research confirms previous studies. When grown on newly cleared rainforest rather than on land that was cleared long ago, biofuels grown in the newly cleared areas have 55 times greater emissions. Depending on the growing conditions those emissions could be actually 10 times greater than emissions from burning the equivalent amount of fossil fuels.
Industry Is Already Looking Away From Palm Oil Biofuels
It's worth pointing out that while palm oil grown on plantations carved out of Indonesian and Malaysian rainforests is a very genuine environmental problem--as palm oil is really everywhere in foods and, increasingly, in biofuels as well--when it comes to aviation biofuels, palm oil has not be used on many (if any) flights. The industry has looked elsewhere.
Hileman notes that a more sustainable solution to growing aviation biofuels is using feedstocks that generally aren't associated with deforestation or other dramatic land use changes--such as algae and salicornia.
Which is just what the aviation industry has done for the most part. Airlines that have made biofuel test flights have used biofuel blends made from algae, jatropha, rapeseed, camelina--and found them more efficient than petroleum-based fuels.
Scaling production of these feedstocks sufficiently so that current flying demand can be maintained, let alone expanded, is the greater issue. Just blending biofuels 50-50 with petroleum-based fuels would require about 2.5% of the planet's crop and pastureland--an area the size of all of Texas, Oklahoma, Kansas and Iowa combined.