The first flight by a commercial airline to be powered partly by biofuel has taken place. No passengers were on board, and just one of the aircraft’s four engines ran on fuel comprising a 20% biofuel mix together with 80% normal aviation fuel. But with both aviation and biofuels arousing strong emotions among environmentalists, the flight has sparked debate on both these issues. Richard Branson, head of the Virgin Atlantic airline which conducted the flight, hailed it as a ‘vital breakthrough,’ while environmental groups dismissed it as a gimmick.
On Sunday 24 February, a Virgin Airlines Boeing 747 flew from Heathrow to Amsterdam with the biofuel mix helping to power one engine. The fuel was a mix of coconut and babassu oil, which Virgin say came from existing mature plantations and did not compete with staple food sources. Virgin boss Sir Richard Branson said the flight marked a "vital breakthrough" for the entire airline industry.
"This pioneering flight will enable those of us who are serious about reducing our carbon emissions to go on developing the fuels of the future," he said.
But he said fully commercial biofuel flights were likely to use feedstocks such as algae rather than the mix used on the passenger-less flight.
The engine was the same as those used in normal passenger-carrying flights, with only the fuel different. The flight follows a journey from Filton (UK) to Toulouse in France made by an Airbus A380 earlier this month using another alternative fuel – a synthetic mix of gas-to-liquid – in one of its four engines.
Kenneth Richter, of Friends of the Earth, said the Virgin flight was a "gimmick", distracting from real solutions to climate change.
"If you look at the latest scientific research it clearly shows biofuels do very little to reduce emissions," he said.
"At the same time we are very concerned about the impact of the large-scale increase in biofuel production on the environment and food prices worldwide.
Greenpeace’s chief scientist, Dr Doug Parr, labelled the flight a "high-altitude greenwash" and said less air travel was the only answer.
The biofuel debate
From the initial enthusiasm about biofuels as a means of reducing carbon emissions, an increasing number of concerns have been raised about possible impacts on deforestation, and rising food prices as land gets diverted from food to fuel crops. The EU has set a target for 10% of petrol and diesel to come from renewable sources by 2020, but a growing number of academics and institutions have called for this target to be dropped amid concerns that biofuels can do more harm than good for the environment. Pressure groups such as Biofuel Watch claim that the expansion of biofuel production is leading to rainforest destruction, rising food prices and human rights violations. There are also concerns about the amount of water being diverted in arid parts of the world towards producing fuel crops, adding to the water shortages for domestic use and subsistence agriculture.
Two recent studies published in the reputable journal Science are among those that claim that converting native ecosystems for production of biofuel feedstocks can worsen the greenhouse gas emissions they are intended to mitigate. A study by Fargione et al. analysed lifecycle emisions from biofuels, and found that carbon released by converting rainforests, peatlands, savannas, or grasslands often far outweighs the carbon savings from biofuels. Conversion of peatland rainforests for oil palm plantations for example, incurs a "carbon debt" of 423 years in Indonesia and Malaysia, while the carbon emission from clearing Amazon rainforest for soybeans takes 319 years of renewable soy biodiesel before the land can begin to lower greenhouse gas levels and mitigate global warming.
Conversion of tropical ecosytems for energy crops has been discredited in a number of studies for resulting in net emissions, but another article published in Science by Searchinger et al. also reports that when assessed at a global level, ethanol produced from maize grown in the USA is also a major carbon dioxide source, rather than a sink.
"Using a worldwide agricultural model to estimate emissions from land use change, we found that corn-based ethanol, instead of producing a 20% saving, nearly doubles greenhouse emissions over 30 years and increases greenhouse gasses for 167 years," write the authors.
Their assessment is based on the additional land that needs to be converted abroad as a result of increased corn acreage planted for ethanol production in the United States.
The authors say that as US corn exports decline due to domestic use for ethanol, production picks up in other countries where yields are lower, requiring conversion of more land for production, and driving global grain prices even higher. This can have serious effects on food costs for the world’s poor.
In a third study published this year in Science, by Scharlemann and Laurance on 4 January, it was reported that palm biofuel produced on Indonesian peatlands releases 8-21 times more greenhouse gases than from conventional diesel.
But while ‘first generation’ biofuels, based on existing food crops, have been increasingly criticised, the technology is evolving rapidly, as I know all too well: as editor of CABI’s database on biofuels, I have had to rewrite the search profiles used to pick up all the relevant research on biofuels and bioenergy several times to keep up to date with this ever-changing field. Some scientists who have been critical about the impacts of current biofuels on climate change and the environment, believe that new generations of biofuels, which do not require clearing of native vegetation and which use crop materials that normally go to waste, could be the way forward. These include fuels produced from agricultural waste, algae, weedy grasses, and woody biomass grown on lands unsuitable for conventional crops. Scharlemann and Laurance say that biofuels which fare best on environmental effects are those produced from residual products, such as biowaste or recycled cooking oil, as well as ethanol from grass or wood.
Capital costs for ‘biorefineries’ which produce ethanol from lignocellulosic material are much greater than for plants which produce fuel from maize grain, or oil palm, but rising grain prices may make the technology commercially competitive sooner rather than later.
Biofuels are unlikely to be a ‘magic bullet’ in the battle against greenhouse gases, but different biofuels vary enormously in their relative merits. While there are many downsides to growing food crops for uses other than food, new biofuel technologies that focus on fast-growing weedy plants or algae may turn out to be much more beneficial. But don’t expect Virgin’s biofuel flight to win over aviation’s critics just yet.