In the search for solutions to reduce carbon emissions, the use of ethanol as a fuel has emerged as a green option, but the environmental gains are not so evident when some aspects of its production are taken into account. Professor Marcelo Sant’Anna of Fundação Getulio Vargas’ Brazilian School of Economics and Finance (FGV EPGE) recently addressed the sustainability of Brazilian sugarcane ethanol as an alternative to fossil fuels in an article called “How green is sugarcane ethanol?”

The paper points out that sugarcane ethanol comes from a renewable source, is an alternative to fossil fuels and is very important for global energy supplies. However, when looking at the energy substitution process, it is also necessary to evaluate the environmental aspects of ethanol production, such as land use and greenhouse gas emissions throughout the production cycle, as well as possible indirect impacts. In particular, Sant’Anna investigated how much of production growth has come from the use of existing crop areas, due to higher productivity, and how much has resulted from the expansion of cultivated land. This aspect is important because deforestation could cancel out the environmental gains of using sugarcane ethanol as a substitute for fossil fuels.

The study used a dynamic land use model, involving prices, transportation efficiency and decisions regarding planting, replanting and crop area expansion, among other factors relevant to the sugarcane industry. The model’s estimates were based on satellite data.

The economist’s study concludes that 92% of the recent increase in Brazilian sugarcane ethanol production has come from expanding cultivated land and only 8% is attributable to higher yields on existing farmland. Alarmingly, 19% of this newly cultivated land was obtained through deforestation.

A central question is how long it will take for the replacement of fossil fuels with sugarcane ethanol to offset the carbon emissions from the initial deforestation. Sant’Anna’s study estimates that it takes around 20 years for this compensation to be achieved, which is much shorter than the 167 years estimated for corn ethanol in the United States.

This study is an important step toward formulating more informed and sustainable policies for the use of biofuels, highlighting the need for a balance between agricultural production and environmental conservation. By unraveling the complex interactions between agriculture, economics and ecology, Sant’Anna provides a solid basis for future discussions and decisions on the role of biofuels in combating climate change.

To read the complete study, click here.

To find out more about this and other research by Professor Marcelo Sant’Anna, click here.