Water-land tradeoffs to meet future demands for sugar crops in Latin America and the Caribbean: A bio-physical and socio-economic nexus perspective

Abstract

Replacing traditional fossil fuel with bioethanol has been adopted in many countries to reduce carbon emissions and achieve climate mitigation targets. However, the soaring global demand for food and bioethanol in the future may impose heavy environmental pressure on major sugar crops producing regions of Latin America and the Caribbean (LAC) through significant changes in land and water uses. Irrigation expansion in the rainfed dominant cropping areas would partially slow down the land use expansion by boosting yields, but require large-scale investments. This study assesses the future land and water demand triggered by sugar crops expansion from the food-energy-water/land nexus perspective through coupling the Global Agro-Ecological Zones model (GAEZ) with Multi-Regional Input-Output (MRIO) analysis. We further analyse the tradeoffs between water and land use under future scenarios of climate change and socio-economic development regarding to the expected goals of biofuel policies and irrigation expansion strategies in LAC countries due to sufficient local water resources. The results show that the projected water and land demand of sugar crops in LAC would increase by 198% and 205% from 2014 to 2040. Increasing the low- or non- irrigated area up to 50% would mitigate the yield loss and reduce the land demand by 10%, with limited impact on the local water resources in most LAC countries. Major bioethanol producers with limited water demand compared with available water resources, such as Brazil and Argentina, could further promote irrigation to avoid significant landuse change and benefit other countries’ land ecosystems via inter-regional bioethanol trade. While in potential higher water stress countries, including Dominican Republic, El Salvador, Guatemala and Mexico, under bioenergy orientated policy in 2040, reducing biofuel policy targets or importing bioethanol from resource rich countries would be a better option. These results could provide guidelines to balance sugar crops production and sustainable water and land use strategies across LAC.