A nexus in crisis: How Brazil’s push for energy security through sugarcane-based ethanol is affecting its water security

Sammanfattning: As reliance on energy and water resources grow, so do the concerns regarding their security, especially in terms of availability. A projected rise in population, accompanied by the relentless pursuit of economic growth and increasing climate change, indicate that greater stress will be placed on these same resources. Biofuels are considered to be a viable alternative to fossil fuels and sugarcane-based ethanol has become an important source for energy security in Brazil, its main producer. At the same time, water scarcity issues have prompted the Brazilian government to compose its first National Plan for Water Security. Research shows that change in land use, a prevalent factor in the production of biofuels, can greatly impact water resources through evapotranspiration, suggesting the possibility of the existence of a link between the two events. This study aimed to investigate this phenomenon by assessing how Brazil’s push for energy security through the production of sugarcane-based ethanol could be affecting its water security. The state of Sao Paulo and the lower Cerrado, including the states of Goias, Minas Gerais and Mato Grosso do Sul, were selected as units of analysis since they comprise the largest production area in the country and are located within the La Plata Basin, where water issues have been experienced in the recent past. Results showed impressive increases over the past four decades in the amount of sugarcane and ethanol produced, as well as in the expansion of land used to cultivate sugarcane in both cases. Furthermore, the results disclosed an increasing trend in precipitation deficit for both regions. The discussion revealed that the direct land use change engendered by the expansion of sugarcane cultivation for ethanol cannot be linked to the decrease in availability of rainwater since it did not negatively impact moisture recycling. Indirect deforestation caused by the displacement of pastureland was, however, determined to have contributed to reduced rates of evapotranspiration, negatively impacting continental moisture recycling, which is imperative for levels of rainfall in the La Plata Basin. The study concludes that the increased production of sugarcane-based ethanol in Sao Paulo and in the lower Cerrado, aimed to ensure energy security for Brazil, is negatively affecting its water security through reduced rates of precipitation associated with indirect land use change. More generally, this conclusion provides insights into the energy-water nexus and a better understanding of critical tradeoffs and potentially irreversible risks that can come with isolated solutions to issues pertaining to larger, complex systems. Finally, it stresses the importance of a nexus approach for sustainable development.