Tesco is the latest large retailer to join the green revolution, following Marks & Spencer's announcement of its plans to become 'carbon-neutral' by 2012.

The supermarket giant has unveiled plans to cut carbon emissions and encourage its customers to buy green goods. It has developed a 'carbon footprint' labelling system for its products - giving consumers information about how much energy goods have taken to produce and where they have come from by putting aeroplane symbols on goods brought into the store by air freight.

Chief executive Sir Terry Leahy also promised to halve the price of energy-saving light bulbs and broaden Tesco's Value range of affordable energy-efficient goods. The supermarket also plans to cut carbon emissions by at least 50% by 2020, provide more bio-fuels in its petrol stations, and restrict goods carried by air to less than 1% of the store's total stock.

Sir Terry told the BBC:

"I am determined that Tesco should be a leader in helping to create a low-carbon economy.

"If we fail to mitigate climate change, the environmental, social and economic consequences will be stark and severe."