Evaluation of Greenhouse Gas Emissions from Small-scale Coffee Producers in Kiambu-Kenya Based on Calculations of the Cool Farm Tool

Abstract

Coffee plays an important role in sustaining millions of livelihoods around the world. The effects of climate change on coffee are already perceivable. Coffee besides suffering from climate change is also a contributor. Understanding greenhouse gas (GHG) emissions from coffee supply chains is important for evaluating options for climate change adaptation and mitigation within the sector. In this study, data from 108 small scale farmers and three wet mills under Ndumberi Coffee Growers Cooperative was used to calculate the carbon footprint of coffee parchment and identify emission hotspots within different management levels. Management level was found to be the main cause of variation in carbon footprints. Carbon footprints for 1kg of fresh coffee cherries were between 0.04-0.07 kgCO2e for high management level, 0.22-0.28 kgCO2e for medium management level and 0.53-0.58 kgCO2e for low management level. The main contributor to greenhouse gas emissions across all the management levels was the inputs of organic and inorganic nitrogen. At the wet mills the main source of greenhouse gas emissions was the processing wastewater. The carbon footprints at processing for 1kg coffee parchment were 2.64 kgCO2e for Riabai wet mill, 2.62 kgCO2e for Ngaita wet mill and 2.40 kgCO2e for Ndumberi wet mill. From the results obtained, a site specific mitigation framework is proposed to suit the capabilities of different producers.