Water & Cotton
Based on the water footprint concept (check Step #2), our products undertake quite a journey until they are part of our daily lives. These journeys are getting longer and collect even more water if they start far away from regional markets and if they are made up of raw materials that are water-intensive like cotton for example.
From the cotton production at field level (agricultural stage) to the processing of seed cotton into final cotton products (industrial stage), different types of ‘water-impacts’ on the elements of the natural water cycle exist: (1) evaporation of infiltrated rainwater for cotton growth, (2) withdrawal of ground- or surface water for irrigation, and (3) water pollution due to the leaching of fertilisers and pesticides.
As cotton is grown in warm climate and often irrigated, especially the second impact carries a high risk for overexploitation of water resources due to water abstractions for cotton fields – on average, one third of the water footprint of cotton can be considered as blue water (again, check Step #2). However, the three impacts can vary depending on the region where cotton is grown (e.g. China, India or Bangladesh), where it is further processed in the textile industry (e.g. Malaysia) and where the final cotton clothes are exported to (e.g to the European market). Thus, and in order to break down the impacts (1-3) of consuming cotton products on global water resources, the origins of the product need to be tracked. As a result, the water footprint of cotton fabrics varies from place to place and from the specific life cycle.
According to Mekonnen and Hoekstra (2011 and 2013), the global average water footprint of cotton fibres is approximately 10,000 litres per kg. Resulting in 2,500 litres needed for the production of a single cotton T-Shirt. If we remember the 120 litres per capita and day in a German household, this would cover our daily water demand for more than 20 days. As comparison, the footprint of e.g. hemp fibres has a global average water footprint of approximately 2,700 litres per kg, which is substantially smaller than that of cotton.
- The role and business case for existing and emerging fibres in sustainable clothing: final report to the Department for Environment, Food and Rural Affairs (Defra) - Turley, D. B. et al. - 2010
- The water footprint of cotton consumption: An assessment of the impact of worldwide consumption of cotton products on the water resources in cotton producing countries - A.K. Chapagain et al. - 2005
- The green, blue and grey water footprint of crops and derived crop products - M.M. Mekonnen, A. Y. Hoekstra - 2011
- The water footprint of modern consumer society - A. Y. Hoekstra - 2013