Regular readers of TreeHugger will be aware that aviation is becoming an increasingly hot topic in environmental circles. Readers will also be aware that Richard Branson, the owner of Virgin Atlantic, has been trying to position himself, and his company, as environmental leaders in the aviation industry. In particular, Virgin have been making big claims about developing biofuels that could one day replace kerosene in jet engines, something that many people claim can't be done (see George Monbiot's attack on Virgin, and Virgin's response here). We first reported on Mr Branson's claims here, when he announced he was looking at cellulosic ethanol for jet fuels, and that they might replace fossil fuels in the next 20 — 30 years. We later posted on this again with an update, when Mr Branson was not talking about ethanol anymore, but 'a new kind of fuel', which he claimed could be working in cars and trucks within a year, and airplanes within five years. In between then and now, the Virgin boss also announced that he would be ploughing all of his profits from his travel companies (he also own Virgin Trains in the UK) into renewable energy, claiming this would amount to $3bn in investment. It doesn't end there, however. According to a recent report on Sky News, Mr Branson is at it again. Apparently he now hopes to run a test flight of a Boeing 747-400 using biofuel by the end of next year, and the first passenger flights could be taking off within the next two years. Virgin have apparently been working with GE and Boeing on the initiative, and they will be testing a number of feedstocks, including soya, vegetables and newspaper. If you follow the video link on the Sky page, Mr Branson also explains in an interview (from what appears to be a computer simulation of a Virgin plane) that one of the big challenges is finding a fuel that doesn't freeze at high altitude, and hints that this is leading them to look at butanol, rather than ethanol. Encouragingly, he also emphasizes that they are looking at developing cellulosic biofuels "so that one's not just using the corn or the sugar, but we're using the stalks, we're using the prairie grass, and we're using the willow trees." This should at least go some way towards relieving fears that biofuels will threaten food production. All is not certain, however: "" it's by no means guaranteed that it will be successful, but if we can succeed, hopefully people will one day be able to fly on planes without emitting carbon."
Of course, until the public are able to see the fruits of Virgin's labors, and to corroborate firstly, that his new fuels work safely in aircraft, and secondly that they do genuinely offer a decreased environmental footprint compared to conventional jet fuel (remember the palm oil debate!), we will refrain from getting too enthusiastic, but we do note that there is plenty of research and debate going on elsewhere into alternatives for the aviation industry. For a small sample of what's been going on, check out our post on the sustainable-energy initiative between the University of North Dakota and North Dakota State University in Fargo, and their research into low-temperature tolerant biofuels. See also our Q&A; on biodiesel in airplanes, and research by NASA, GE and others into halophytes — salt water plants that could be grown in desert areas to provide biofuels for aviation (and maybe increase rainfall in the process). Of course, it's not just about what fuel you use — landing jumbo's in idle, and towing planes to a starting grid can also significantly reduce emissions.
This is pretty much a standard disclaimer now, but alternatives to air-travel are likely to remain significantly greener for the foreseeable future, so check out the man at Seat 61 for truly efficient travel options.