Estimation of carbon footprint of tea products at nyabihu tea factory, Western Province-Rwanda

The carbon footprint arose out of the debate on climate change, as a tool to measure GHG emissions. This research carried out at Nyabihu tea factory for carbon footprint estimation in tea life cycle was focusing on different key processes and phases or steps through which Nyabihu tea passes until it is delivered to the auction site (Mombasa). Data collection involved: (1) questionnaire survey to assess the life cycle of tea for Nyabihu tea, (2) field observation and measurements (forests and tea plantations), and (3) personnel interview. The study found that carbon footprint from tea production depends on different factors including, transport, burning fuel woods, energy use and fertilizers application which contributed to releasing nitrous oxides (N2O), carbon dioxide (CO2) and methane (CH4) in the atmosphere. The amount of the three greenhouse gases emitted from the life cycle was expressed in terms of the amount of carbon dioxide equivalent (CO2eq) units as calculated by the Cool Farm Tool 1.1 software. The emission from total area is 150467.3690tCO2eq. Most of carbon dioxide equivalents were found to be released from off farm activities with a total of 135kg CO2eq per kilogram. The greatest amount of greenhouse gases emitted is due to transport. The total annual emission from the tea life cycle is -365.31kgCO2eq per kilogram of finished product. But in terms of compounds the largest emissions in CO2 equivalents come from N2O where 0kgs of N2O equate to 0.696kgCO2eq per kilogram and the least is from CH4 (i.e. 0.0kgCO2eq of CH4 per one kilogram). Measures to reduce emissions in order to protect the environment were undertaken by Nyabihu tea factory. These include enhanced sequestration through forest and agroforestry trees plantation which accounted for sequestration of 406744.48116tCO2/hectare sequestered. In order to reduce carbon dioxide and other greenhouse gases emissions, agricultural techniques including appropriate use of fertilizers should be changed to help efficient sequestration of carbon in the soils since soil can act as an effective carbon sink. Furthermore, the management of wastes and tea crop residues through incorporation into the soil will provide more advantageous carbon storage.