The aviation industry is under pressure to reduce greenhouse gas emissions
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Airlines could soon start using fuels based on animal fats to meet their climate targets. However, this could increase rather than reduce carbon emissions, warns a report for action group Transport & Environment.
European Union regulations encourage the use of animal fats as fuel and also require airlines to increase the share of “sustainable jet fuels” they use by 2030. Several oil companies have announced plans to begin producing jet fuels from animal fats, which are expected to be the second most important source of so-called renewable fuels after used cooking oil.
There are two main problems with converting animal fats into jet fuel for the purpose of reducing greenhouse gas emissions. The first is that although animal fats are waste products from the meat industry, they are already being used. “With used cooking oil, the biodiesel industry has largely used something that was not put to good use, but with animal fats it is different,” says analyst Chris Malinsthe author of the report.
In 2006, the meat industries in the UK and the European Union produced approximately 2.4 million tonnes of rendered or purified fat. This fat was used in roughly equal proportions in animal feed, to make products such as soap and to generate heat and power – often by the rendering plants themselves. Only a small percentage was converted to biodiesel.
In In 2021, the UK and EU produced about 2.8 million tonnes of rendered fat, almost half of which was converted into biodiesel, mainly for use in cars and trucks, with the rest going into pet food and cosmetics. Almost none are used directly for heat and power anymore.
This means that if the aviation industry starts using significant amounts of animal fat to make what it calls sustainable jet fuel, there will be less left over for these existing purposes. The cosmetics and pet food industries are likely to replace it with palm oil, says Malins, because it’s the cheapest product with similar properties.
That means more forests will be cleared to produce more palm oil, which could lead to an increase in emissions of up to 70 percent compared to continuing to use fossil fuels to power planes, the report said.
The second major problem is that using animal fat-based fuels provides the airline industry with a relatively cheap and easy way to meet its very modest targets for increasing the use of “sustainable jet fuels,” says Malins. It’s an alternative to investing in more expensive but better approaches, such as cellulose-based biofuels, which are made from the fibrous parts of plants, he says.
Because there is little animal fat, this is not a long-term solution. Demand for jet fuel in the EU is expected to reach around 46 million tonnes of crude oil equivalent per year by 2030. If all the animal fat produced in the EU were converted into jet fuel, it could supply a maximum of 3 percent of that, Malins calculates. That’s not surprising, since the fat of 8,800 pigs would be needed to fuel a flight from Paris to New York.
There is a broader problem here. Using waste biomass can be really green, unlike growing biomass for energy. But most of the waste biomass that can be used is used, so regulatory incentives aimed at encouraging the use of waste can have unintended and unwanted consequences.
For example, the EU’s incentives to convert used cooking oil into biofuel have led countries in Asia to export used cooking oil to the EU that was previously fed to animals, among other things. Those countries must then replace that oil with other products, increase emissions. In some cases, According to environmentalists, unused oil is even sold as used. Likewise, much of the “waste wood” burned in power plants maybe no waste at all.
As far as aviation is concerned, the fact is that there are simply no truly sustainable zero-emission fuels available in the quantities needed at the moment. Aside from improving energy efficiency, the only short-term way to reduce aviation emissions is for people to fly less.
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