Supermarket giant Tesco has unveiled wide ranging plans to cut carbon emissions and encourage its customers to buy green.
The UK should aim for a low-carbon economy, Tesco's boss says
Tesco said it aimed to develop a carbon footprint labelling measure for all products sold in store, and cut the cost of many energy-efficient goods.
The new "green" labels would allow customers to compare and shop for items which required less energy to produce.
The firm is the latest major retailer to boost its green credentials.
Marks & Spencer earlier this week announced a £200m plan to make the company carbon neutral by cutting energy consumption and stocking more products made from recycled materials.
Wal-Mart, the world's biggest retailer, recently said it planned to cut packaging by 5% over five years.
A government-sponsored review by former World Bank chief economist Sir Nicolas Stern last year warned that urgent action was needed to tackle global warming.
Tesco unveiled its carbon labelling and emissions proposals in a speech given by chief executive Sir Terry Leahy.
He said Tesco planned to halve the price of energy-efficient light bulbs and offer more energy-efficient products in its cheaper Value range of goods.
The group also plans to cut emissions from existing stores worldwide by at least 50% by 2020, and would seek to restrict air transport to less than 1% of the firm's products, he added.
Supermarkets have come under increasing pressure from campaigners for the environmental impact of transporting their goods by road and air.
Sir Terry said the supermarket would put aeroplane symbols on all goods imported into the country by air, and work with key suppliers such as Unilever to reduce Tesco's indirect carbon footprint.
Tesco said it also planned to double the proportion of biofuels it sells at its petrol stations across Britain.
"I am determined that Tesco should be a leader in helping to create a low-carbon economy," Sir Terry said.
"If we fail to mitigate climate change, the environmental, social and economic consequences will be stark and severe."
Sir Terry will be answering questions from BBC News website readers on Tesco's green initiative between 1130 and 1200 GMT on Friday.
The company's new carbon policy demanded that it transform its business model "so that reduction of our carbon footprint becomes a central business driver", Sir Terry said.
Tesco said that its current direct carbon footprint in the UK was about 2 million tonnes of carbon dioxide (CO2) a year, with mass refrigeration of produce accounting for roughly a third of emissions.
The firm said it had commissioned independent research to map the total carbon footprint of its businesses across the world.
Tom Delay, head of the government funded Carbon Trust, welcomed Sir Terry's announcement.
"A carbon label will put the power in the hands of consumers to choose how they want to be green," he said.
"It will empower us all to make informed choices and in turn drive a market for low carbon products."