Retailer M&S tied with telecoms group BT on the top spot in a carbon reporting leader board of FTSE 100 companies.
Each company in the FTSE 100 was scored using publicly available data against 67 criteria to rate their carbon management strategy.
Carbon Clear which did the rankings said Marks and Spencer impressed with their range of “engagement activities” and for offsetting their emissions.
Meanwhile it found BT was best at using climate change science to develop reduction targets and programmes to cut emissions in their value chain.
Others making it into the top 10 were: Unilever, Tui Travel, Sainsbury’s, National Grid, BskyB, Kingfisher, Coca-Cola HBC, with Aviva and Mondi joint 10th place.
Not everyone does as well though according to Mark Chadwick, Carbon Clear Chief Executive.
He said: “For the fourth year in a row our research demonstrates that although many FTSE 100 companies report information about carbon, there’s an increasing gap between the best practice leaders and other businesses.”