The global warming potential of production and consumption of Kenyan tea

Kenya is the third largest producer of tea in the world, the majority of which is exported, contributing 20% to the total national income from exports. Yet, its environmental impacts are currently unknown. This study considers for the first time one of the impacts - the global warming potential - of production and consumption of Kenyan black tea. The system boundary is from 'cradle to grave'. Both small- and large-scale production of tea is considered. The functional unit is defined as 1 kg of dry tea and the tea is assumed to be consumed in the UK. The results suggest that the total impact of tea is equal to 12.45 kg CO2 eq./kg of dry tea for the large-scale and 12.08 kg CO2 eq./kg for the small-scale production, indicating that the scale of production does not influence the impact. The main contributor is tea consumption which is responsible for 85% of the impact because of the electricity used to boil water. Tea cultivation and processing contribute around 10% to the total. The contribution of transport is relatively small (4%). The global warming potential from waste management is negative because of the credits for recycling of post-consumer tea packaging. The results are most sensitive to consumer behaviour, with the impact almost doubling with doubling the amount of water boiled for each cup of tea. Drinking tea with milk has even greater impact, increasing the total impact by up to three times. Appropriate consumer engagement programmes are needed to encourage behavioural change.