Friends of the Earth commissioned environmental data analysts Trucost to estimate the total land and water footprint of seven generic everyday products: a cotton t-shirt, a smartphone, a cup of tea, a cup of coffee, a chicken curry ready meal, a pair of leather boots, and a chocolate bar. We also asked Trucost to estimate the company and sector footprints for three of the products (t-shirts, chocolate bars and smartphones) and the toy and game sector to gain an insight into the scale of resource demand generated by these products.
The results reveal the intensive resource demands of some products – a single smart phone for example requires 18m2 of land and nearly 13,000 litres (13 tonnes) of water. With a billion smartphones sold worldwide in 2013, the smartphone industry uses a significant amount of water. But the findings also reveal the importance of looking at the different stages of the supply chain. A pair of leather boots requires 50m2 of land and 25,000 litres of water, yet if the waste from the leather tanning process is treated in a waste treatment plant, water demand is reduced to 14,500 litres.
Figure 5: The land and water footprints of a cotton t-shirt
This is based on the land and water used to manufacture the cotton including farming the cotton, bleaching, dyeing and printing the fabric, and manufacturing the garment.Cotton farming is the most resource intensive part of the production process, accounting for 65% of the overall land footprint, and 68% of the total water use. On average, over 9,900 litres of water are needed to grow enough cotton seed for 1 tonne of cotton textile - the equivalent of more than 120 baths of water.15 Almost one third of the overall water use is blue water, used to irrigate the cotton crop.The United States, India and China are the main producers of cotton globally, with the United States, India and Uzbekistan the largest exporters.16Irrigated cotton is water intensive and cotton is estimated to consume 3% of the total water footprint for crop production globally.17 Cotton farming in Uzbekistan has almost completely drained the Aral Sea which has shrunk to 10 percent of its former volume.
Figure 7: Distribution of land and water use across the supply chain for a cotton T-shirt. These calculations assume that 667g of seed cotton are needed to manufacture one 250g cotton t-shirt,22and that one hectare yields 2.04 tonnes of seed cot-ton.23 The calculations are based on sector averages and used life cycle analysis and Trucosts’s E I-O mod-el to estimate the footprints. They do not represent a specific manufacturer’s t-shirt.