Comment

Biofuels are needed more urgently than ever, but issues of land use change and management must be considered first, say Jeremy Woods, Seyed Ali Hosseini and Nilay Shah

Biofuels and bioenergy in general go through cycles of heady support followed by widespread disparagement. On the up part of these cycles, biofuels tend to be perceived as a ’silver bullet’ solution, with unrealistic expectations driven by threats to energy security. For example, the 1973 Suez oil crisis led directly to Brazil establishing its much vaunted ’Proalcool’ programme - using sugarcane to produce ethanol as a transport fuel to reduce foreign exchange expenditure on oil. The US corn ethanol programme was spurred on by similar concerns.

These concerns over oil go back to the birth of the internal combustion engine. Indeed, in 1916, Henry Ford himself stated: ’There’s simply no two ways about this fuel question. Gasoline is going - alcohol is coming. It’s coming to stay, too, for it’s in unlimited supply.’

And yet nearly a century later, substantive questions continue to be asked about whether biofuels have a sustainable future in any form. Not only are they more dispersed and have inherently lower energy density than fossil fuels, but they are also embedded in agricultural and forestry production systems. Any rapid expansion in supply, therefore, requires sizable financial support and steadfast policies that challenge the status quo in rural areas. These challenges include: changes to cropping patterns and agricultural markets; pressures on biodiversity, water availability and quality; and the visual amenity of the landscape.

Food and fuel 

Despite these questions, there has never been a more urgent need for biofuels. There are crucial areas of the transport system that other renewables can’t reach and agriculture in particular is becoming increasingly vulne
rable to rising and increasingly volatile fossil fuel prices. 

We must not allow the biofuels question to be dominated by battles over big cars. Instead, we need to focus on the unique role of biofuels in providing sufficiently energy-dense fuels for: trucks and trains to haul heavy loads over long distances; aeroplanes to get off the ground and fly across oceans; tractors to plough fields; and combine harvesters to get crops from the fields into storage and distribution systems. 

From this perspective, biofuels will actively support food production, rather than competing for it: ’food and fuel’, rather than ’food versus fuel’. Individual supply chains are the focus of rapid technological innovation and development, particularly in terms of knowledge about the impacts of specific activities and crops and the management practices that need to be changed in order to minimise negative impacts and enhance positive ones. Such innovation, applied throughout the supply chain, is leading to technological breakthroughs that substantially reduce processing energy requirements. Meanwhile, genetically modified crops can ultimately decrease the cost of feedstocks. But the major source of profit for biofuel production relies on the sale or use of by-products, for example in food and pharmaceutical supplements or in biomaterials, such as animal feeds and bioplastics. Careful integration of conversion technologies and feedstock production will maximise the financial return per tonne of raw biomass processed and also per kilogram of carbon fixed through photosynthesis.  

Large-scale global production of biofuels can also help to stabilise energy (oil and gas) markets. The widespread availability of biofuels should dampen down the pressures driving the volatility in the oil price. From a climate change mitigation perspective, there is something of a conundrum. Biofuels could potentially support the continued release of the ancient geological stocks of carbon currently locked up in the fossil fuel reserves. Indeed, to make a substantive contribution to climate security, bioenergy and biofuels, along with the other forms of renewable energy, need to be able to substitute substantial fractions of fossil-energy demand. This must happen without mining the stocks of carbon currently in the active carbon cycle in, for example, terrestrial vegetation (biomass). 

Plan ahead 

With the right governmental strategy and long-term planning, biofuels will increase energy security, reduce greenhouse gas emissions and help with the social development of rural areas by, for example, decreasing unemployment. 

Favourable wider environmental impacts are also possible, including those on biodiversity and hydrology, but they will require increasingly detailed management and integration with food production. In many ways, the intense debate surrounding the future development of biofuels throws down the gauntlet to the food and biomaterials production sectors. Without the new understanding currently being driven by the biofuel debate - particularly around land management and land use change - it would not be possible to envisage ways to produce sufficient food and materials for the world and to develop the policies needed for a sustainable future. 

Jeremy Woods is a lecturer in bioenergy and Nilay Shah is a professor of process systems engineering at Imperial College London, UK. Seyed Ali Hosseini is a lecturer at the University of Surrey