The report, called 'How Green is Your Supermarket', was compiled by Liberal Democrat MP Norman Baker. It focused on the nine leading UK supermarkets - Tesco, Asda, Sainsbury, Safeway, Morrisons, Somerfield, Co-op, Marks & Spencer and Waitrose.
Using data supplied by the supermarkets themselves, the study sought to establish just how much waste and pollution is being generated by the food sector, to what extent local sourcing is being used and how much energy is being consumed.
Emissions are still a major cause for concern when it comes to distributing goods. Just three of the chains used rail to transport products (a reflection of the parlous state of the UK rail network as much as anything else), while some lorries were running at just 60 per cent capacity.
Half of the retailers questioned said they had green travel plans in place at head office and were feeding them out to individual stores, while half also said that they used biodiesel or other alternative fuels - although only for around 11 per cent of their fleet. Safeway was the market leader in this regard, while Asda was ahead of the rest in shifting more of its distribution to the rail network.
The Baker report also criticised supermarkets for not doing enough to support local producers. Just 1 to 2 per cent of supermarkets' turnover comes from local food providers. This has serious implications on the environment - food which has to travel further uses more fuel and causes more pollution.
Co-op was the notable exception to this, with some 55 per cent of its produce sourced within a 30 mile radius of the store. Waitrose also has a scheme designed to increase local sourcing, while Asda is also a strong supporter of local goods.
Recycling rates was another key topic. Under EU law, all retailers have to recycle at least 19 per cent of the paper and cardboard they use, but most go much further than this. Waitrose, for example, recycled up to 95 per cent of its cardboard packaging, and the others recycled between 70 per cent and 93 per cent on average.
Again, the Co-op was ahead of the pack, using recycled cardboard and plastic from its stores for the packaging of its own brand products, and is one of the few chains not to use polystyrene trays for the majority of its fresh produce trays. Tesco introduced reusable plastic trays for its fresh produce in 2000.
Plastic bag usage came under fierce criticism. One unnamed retail chain distributed a whopping nine billion plastic bags last year, more than all the others put together. Half the chains already offer some form of biodegradable bag and all of them offer reusable bags, but more still needs to be done to cut the number of bags in circulation.
Encouragingly, most stores were open to some form of plastic bag tax, but not in the same way as that currently in place in Ireland, where customers are charged €0.15 per bag and where plastic bag consumption has dropped 90 per cent as a result. But according to UK retailers, such a system would mean that fewer carrier bags would be used for rubbish collection, in turn increasing sales of bin liners and paper carrier bags, both of which use more energy to produce and transport.
Some stores are already doing more to tackle the plastic bag problem. The Co-op, traditionally the UK's most environmentally and ethically aware supermarket group, was the first to provide biodegradable bags, and now provides them in 10 per cent of its stores, while Somerfield offers them in all of its outlets. Tesco recently decided to roll out a new biodegradable bag which breaks down within just two years.
In conclusion, the study called for more action from both the retailers themselves and from government. In particular, a more in-depth investigation of the impact of plastic bag use and a possible change to the recycling legislation to reduce the use of cardboard packaging was recommended.
In addition, better reporting of recycling rates from the supermarkets, a commitment to reduce lorry mileage and a pledge to source more products from local suppliers were also called for.