Analysis of the Use of Bioethanol as a Mitigation Measure and its impact on the Water Sector: a Study in a Sugarcane Region in Mexico

Abstract

The use of biofuel in transport is a mitigation measure to reduce emissions of greenhouse gases, but may have negative environmental effects. This research analyzes the current and future impact of the production of ethanol from sugar cane in Mexico's water resources. The water footprint, availability, and demand of water in a sugarcane region of the country were estimated, based on a water balance and local climatic conditions. The results showed that the historical water footprint (1980-2007) of sugarcane was 104.9 m3/ton, considering the use of furrow irrigation. However, in the studied region three irrigation systems (furrow, spraying and drip) are used, so the water footprint varies between 58.7 and 73.4 m3/ton, indicating savings of 20% (33 Mm3) of water. The availability of water in the region was estimated at 255 Mm3/year with a stress index of 60%, indicating a high degree of pressure on the water resource. For future scenarios of climate change it was estimated that the water footprint increased 3%; however, the water balance showed that this relatively small increase will have a significant impact on the water demand. Mexico has water availability 18 times smaller than Brazil and almost 7 times smaller than the U.S., so the alternative of producing ethanol requires the study of each of the sugarcane regions to assess their advantages and disadvantages.