It's bad enough for some prop planes to be explained as being powered by rubber bands. Now the cynics might start having a dig at industrial aircraft flying on whatever from cooking oil to liquefied algae.

With the civil aviation industry under increasing pressure from increasing oil costs and environmental legislation, the race is on to find feasible alternatives to standard kerosene and these so far appear to come down to different kinds of biofuel.

Not surprisingly, the first trials of alternative fuel were initiated by British aviation leader, Sir Richard Branson, whose Virgin Atlantic started London to Amsterdam flights with minimal biofuel usage in 2008. This was quickly followed by Lufthansa and Air New Zealand who each utilized various blends of routine fuel and bio derivatives consisting of some from made from jatropha curcas which can grow in soil considered too bad for growing mainstream foodstuffs.

jatropha curcas is a genus of approximately 175 succulent plants, shrubs and trees (some are deciduous, like Jatropha jatropha curcas), from the household Euphorbiaceae.

In 2007 Goldman Sachs pointed out Jatropha curcas as one of the very best prospects for future biodiesel production. It is resistant to drought and pests, and produces seeds 27-40% oil.

Recently, US aerospace giant Boeing, Brazilian aeronautical major Embraer and the Sao Paulo state Research Support Foundation relocated to perform research and development into using biofuels to power jet airliners. It was reported that Brazilian airlines Azul, Gol, TAM and Trip would act as tactical specialists for the job.

The current airline to start exploring with brand-new fuels is the Alaska Air Group which has conducted internal US flights utilizing a blend of 80 % petroleum based fuel and 20% biofuel made from cooking oil. This mix, it is declared, can cut harmful emissions by 10%.

One actually encouraging development has been the relocation far from biofuels which compete head on with food consumers consequently preventing a cost spiral. Not so long ago, a rise in usage of biofuels in automobiles caused a spike in maize costs as US farmers diverted too much corn to fuel processing.

Hopefully in the future, airlines and motorists will focus biofuel intake on non-food sources such as jatropha and algae. It would be a combined blessing certainly if some people ended up starving simply to satisfy another person's green qualifications.