A new study, designed by IIASA researchers for conservation charity WWF, has found that while there is a small but not insignificant potential for the production of sustainable biofuels in sub-Saharan Africa, this should be prioritized for the aviation industry which has limited other options when it comes to reducing carbon emissions.
It is estimated that by 2050, global aviation could account for over 22% of all global carbon dioxide emissions due to rapid growth in air traffic, and with limited operational and aircraft design options for reducing emissions, there is a need for more low-carbon fuels.
The WWF report, titled Taking off: Understanding the sustainable aviation biofuel potential in sub-Saharan Africa, looks into the current and future potential of biofuel feedstock production in sub-Saharan Africa using the strict sustainability criteria of the Roundtable on Sustainable Biomaterials (RSB) standard.
These criteria exclude any crops and biomass residue which would result in negative environmental and social impacts, such as food insecurity, unsustainable use of scarce resources like water, land, the destruction of biodiversity and insufficient reduction of greenhouse gases.
Among the key findings are:
- Sub-Saharan Africa could at best contribute between 30% and 90% of long-term alternative aviation fuel demand in the form of RSB-compliant aviation biofuel produced from energy crops on approximately 84 million hectares of prime and good quality land and another 157 million hectares of moderately suitable land.
- This assumption holds that all energy crops on suitable land in sub-Saharan Africa would be reserved for the exclusive production of biofuels for aviation.
- The highest greenhouse gas savings are typically achieved by perennial crops. To incentivize farmers to invest in the cultivation of such crops, the aviation industry and fuel suppliers should sign long-term off-take agreements to mitigate the risks related to their production.
- Annual energy crops could be planted on degraded land (such as the rehabilitation of mining land) and could replace other industrial crops in decline. An example would be replacing tobacco crops for the cigarette industry with Solaris tobacco which is a tested feedstock for biofuel.
- Because shipping feedstock long distances could reduce the greenhouse gas savings, the finished product should ideally be processed locally to develop a local biofuel value chain and industry.
“The transition to a low-carbon economy with biomass as one of its energy sources will intensify the energy-agriculture linkage and add a new dimension to agricultural systems, heighten resource competition in the food system, and may provide new opportunities for rural communities. As food, feed and energy feedstock markets integrate more closely, both challenges and opportunities arise. Increasing biofuel feedstock production in sub-Saharan Africa, while at the same time meeting food demand targets and strictly following sustainability principles, faces a high degree of complexity. Integrated system analysis such as this helps unpack those complexities and will hopefully contribute to a better informed debate and policy development on the topic,” says IIASA researcher Sylvia Tramberend.