Gesticulating at thirty thousand feet
Richard Branson has flown one of his aircraft on biofuels. Two interesting points come out of it.
Firstly, the green lobby has had to accept both that reducing carbon emissions can have economic consquences and that those consequences can be unacceptable. Specifically, various people have (rightly) pointed out that, at the moment, growing crops for biofuels means less land for foodstuffs. There is a possibility that this could be circumvented by using algae grown on water or on otherwise unproductive land. However, most unproductive land is unproductive for a reason – it is inhospitable – and water, whether fresh, brackish or salt, is an ecosystem wherever it naturally occurs. Even the underside of Antarctic ice shelves have their own bioscapes. This is an economic output; by accepting that some of the measures that could be used to reduce carbon emissions have unacceptable consequences, the debate shifts from being one of sticking heads in sand to one about give and take. Indeed, you could say that all flying should be stopped immediately; this would make airlifts and search-and-rescue much harder.
In reality, people are not going to stop flying. Greenpeace protesters today put a banner on top of a plane that said ‘Climate Emergency – No 3rd Runway’, failing to notice that an airport is full of, er, air passengers who would quite like their transits to be speeded up by another runway and a lack of protestors.
Secondly, it shows the scale of the problem. The aircraft had 20% biofuel (coconut oil and babassu oil) in one of its four tanks. That required the oil of (wait for it) one hundred and fifty thousand coconuts. To actually run the Jumbo on biofuel alone, you’d need three million coconuts’ worth of oil for one flight. Babassu oil grows in the Amazon so, despite Richard Branson’s protestations of rainforest friendliness, you’d need to lay on transport to the rainforest at the very least. Petroleum has, compared to other fuels, a high energy density. This allowed us to be remarkably inefficient in using it and allows for progressive, technological improvements in efficiency. However, this energy density also means that people are trying to replicate (in this case) jet fuel or avgas rather than replace it. Coal-to-liquid technology is being pressed with rather more success because the end product is a lot closer, along the life-cycle and in cost terms, to avgas.
While syngas reduces reliance on oil, it doesn’t do anything for carbon emissions. It is more-or-less possible that you can take out as much carbon as you emit with biofuels. In order for it to work, however, some new ideas are going to have to be accepted. EasyJet, for instance, have asked for an open-rotor design. These are more fuel-efficient (as they have a higher bypass ratio) but are noisier (as there is no shroud to keep noise inside the engine). Is the extra noise worth the reduction in carbon? Restating the above, are the economic implications worth the reduction in carbon emissions, given that we have to convince people of the benefits?
The problem with fossil fuels is that they are both the energy source (in human timescales) and the transport method and the storage form. We will have to get used to source, transport and storage being different. It may be that a solution to the wind now blowing all the time is to connect wind farms to hydrogen plants and then burn the hydrogen at leisure, possibly sending it down existing power lines.
The link between Richard Branson and Greenpeace should be clear; posturing achieves relatively little. I think that reducing carbon emissions from air transport requires a mix of approaches. There is no silver bullet and there is not, I think, anything that is going to stop people flying. Working with OEMs, particularly engine manufacturers, would do more for reducing carbon emissions than stunts. Equally, convincing people to vote for (say) per-plane rather than per-passenger air duty would be a better use of Greenpeace’s efforts than annoying some air passengers; they could even campaign for more trains. After all, they’re the ones who have to be convinced.
xD.
