Campaigners have urged companies to measure their resource use after research highlighted high land and water use in manufacturing popular products.
A smartphone uses nearly 13,000 litres of water and 18 square metres of land, the study found, with two fifths due to pollution during manufacturing and assembly.
A pair of leather boots requires 14,500 litres of water, but this rises to 25,000 litres where leather tanneries dump untreated chemicals into the environment, according to the report.
A 100g bar of chocolate uses 2.5m² of land and 1,400 litres of water, while a t-shirt requires four litres of water and just over 4m² of land, the research revealed.
The research was undertaken by Trucost for Friends of the Earth (FoE). Trucost calculated the footprints using sales data from 2011/12, product lifecycle reports and its environmental input-output model, which calculates impacts through supply chains by combining economic flows and environmental data.
FoE is calling for all large companies to examine and report on the resource footprints of their products and supply chains. Some companies have made progress, particularly on greenhouse gas reporting, it noted.
Some are also reporting on freshwater use, and have identified supply risks where suppliers are based in water-stressed regions.
Sony and Samsung report on the amount of water they use to safely dilute pollution caused by manufacturing operations. Sony also reports on rainwater use in Japan and China, and is the only company measuring its annual global raw material use across its supply chain, according to FoE. Nokia is the only company FoE found to be reporting on its land footprint.
FoE advocates reporting on land, water, materials and greenhouse gases so that changes can be monitored. This, it says, would avoid a repeat of the mistakes experienced with the renewable fuels obligation, which focused on greenhouse gas emissions savings by crop-based biofuels but ignored the potential impacts this could have on demand for land and food prices.
Governments should extend reporting to cover all large companies, FoE recommended. Only publically-listed companies are required by law to report on social and environmental impacts of products. This excludes five out of six large companies across the EU, it noted.
Legislation should include verification and enforcement mechanisms to combat non-compliance or disclosure of misleading information, it added.
FoE also wants the UK government to produce an economy-wide report on the country’s consumption of resources similar to the 2006 Stern report on the economic risks posed by climate changes. This would enable policymakers to develop an effective and evidence-based national resource strategy, it said.
Many organisations are now calling for such a report. Labour and the Liberal Democrats pledged to undertake a resource report before the election, though the Conservatives did not.
Friends of the Earth’s resource use campaigner Julian Kirby said: “In an increasingly populous and environmentally stressed world, it’s more important than ever that companies measure their resource use – for their own sakes as well as the environment’s.
“The good news is that armed with land and water footprint information, companies can redesign their products and business models, to save cash and tread more lightly on the Earth,” he said.
