Louise Karlberg is co-author of a recent paper that looks at how “biomass scarcity” is locking communities in the Ethiopian highlands into vicious cycles in which they are progressively overusing the biomass resources on which they rely. Below she discusses the dilemma ways to tackle it.
Q: What is biomass scarcity?
LK: Well, biomass is used for food, feed, fuel and fibre throughout the world. So, in straightforward terms, biomass scarcity is what happens when the demand for the “four Fs” outstrips supply in a given location. This has already happened in the area we studied, around Lake Tana in Ethiopia.
Q: Why is it a problem?
LK: As populations grow, which of course is happening rapidly in sub-Saharan Africa, there is a need for more food, and therefore a need for more fuel to cook the food. As the demand for biomass eventually exceeds supply, of course there will be shortages of food and fuel. A lack of food is naturally critical – you can’t replace food with something else. Although for the energy sector, there are alternatives.
Q: Can you describe the “vicious cycles” you refer to in your article?
LK: Yes. We worked in the Lake Tana region. And there, as the population has increased, agriculture has expanded into forestland, leading to deforestation. As a consequence there’s now very little forestland left. And because there is no “spare” fuel-wood, people start to burn agricultural waste like crop residues and dung, rather than return it to the soil. Studies show that agricultural land needs about 20% of its above-ground biomass returned to the soil if it’s to remain good for growing food. But it’s getting to the point where there’s a cycle of growing demand, and over exploitation of soil and forest resources. Other densely populated countries are also heading this way – Rwanda for example is importing a lot of biomass, mostly charcoal for fuel.
Q: And what are the potential impacts?
LK: It’s hard to speculate, but the worst-case scenario is degraded croplands and soil erosion. It’s really tough to bring soils back into a productive state. And of course if things go far enough there will be major food shortages, bringing with them a greater reliance on imported food and fuel, and no doubt a lot of negative social impacts.
Q: Your article talks about turning these vicious cycles into virtuous ones. What’s the single most important change that would bring about this transformation?
LK: The biggest single thing that would make a difference is to shift the energy sector away from biomass – ultimately through electrification. If the demand for biomass for fuel were drawn down, the demands for food and fodder could be comfortably accommodated.
Q: But can mass electrification happen fast enough to avoid these vicious cycles?
LK: It would seem not – it’s some way off. There is a need for interim steps, like replacing current cookstoves with more efficient ones, and the creation of local grids. There are several options for local generation of energy such as micro-hydropower, bio-digesters and solar systems. Financing of these schemes is indeed urgent.
Q: SEI has a major new initiative on the water, energy and food nexus. How can a nexus approach help to address biomass scarcity?
LK: In practical terms, a nexus approach is really about the co-evolution of two key processes in the region today: agricultural transformation and energy transitions. If these processes develop without regard for the other they’re likely to work against each other. For example, as agricultural production intensifies, more energy is needed for pumping and storing water, and for machinery. And more water is needed for irrigation. At the same time, around 80% of the energy sector in Ethiopia relies on biomass, and all our estimates show that biomass will continue to play a major role in the near future as well – some of which will originate from agriculture. So there’s really a need to manage these sectors and processes in a joined up way if they’re to move ahead sustainably – that’s the nexus approach.