Carbon and water footprint of Robusta coffee through its production chains in Thailand

Abstract

This study investigated the carbon footprint (CFP) and water footprint (WFP) of Robusta coffee products in the boundary of business-to-business. The scope of work included coffee cultivation, roasted coffee and ground coffee production. The activity data were collected from 180 coffee farms in Chumphon Province (Thailand) in 2015. A national guideline for CFP of products and a guideline of WFP analysis by Hoekstra et al. (The water footprint assessment manual: setting the global standard, Water Footprint Network, Enschede, 2011) were used in this study. The functional unit was 1 kg of each coffee product. In addition, the influences of soil types, crop management, size of coffee farm and co-cultivation of fruits on CFP of coffee product were examined. The results indicated that the CFP of Robusta coffee products was 0.40 ± 0.12 kgCO2e/kg of coffee cherry, 0.55 ± 0.08 kgCO2e/kg of roasted coffee and 0.56 ± 0.08 kgCO2e/kg of ground coffee. Almost 70% of GHG emissions came from use of chemical fertilizer, followed by LPG in roasting process and electricity in grinding process. Crop management and size of planted area had significant impacts on the CFP of coffee cherry. Co-cultivation with other fruits in large-scale planted area could significantly reduce the CFP. The WFPs of Robusta coffee were 10 m3/kg of coffee cherry and 27 m3/kg of roasted and ground coffee. Wastewater from coffee inspection, fermentation, pulping and washing accounted for 68% of total water consumption. Optimal fertilizer application, using high energy efficiency burner during roasting, co-cultivation with fruit trees and rejuvenation were suggested as appropriate mitigation measures for reduction in the CFP and WFP of Robusta coffee.