Prime minister Gordon Brown said he and his family are working to reduce carbon emissions at home, it emerged today.Writing in the Daily Mail in an effort to encourage the nation's supermarkets to "sharply cut" the number of plastic bags used in the UK, the prime minister said he has adapted a number of low carbon measures to his personal life to help better the environment.He claimed that the family has had solar panels installed on the rooftop of their Scottish home to heat water, while also participating in a recycling scheme and composting in the garden.In addition, the prime minister said he is "trying to take the train more", as well as ensuring that the household uses low-energy electrical appliances and turning them off completely when they are not in use, rather than leaving them on standby.The Daily Mail claimed today that supermarket firms Sainsbury's and Tesco have pledged to work to reduce the number of plastic bags they hand out to customers.Earlier this week, retail giant Marks & Spencer announced it would be charging its customers a fee of 5p per plastic bag used at its food outlets.