London mayor Ken Livingstone has launched two schemes designed to slash the city's carbon emissions by 3m tonnes over the next three years.

The "Green 500" aims to convince 500 of London's leading businesses to sign up to independent carbon units and to develop an internal programme to cut emissions in line with the target of a 60 per cent reduction by 2025.

Companies already backing the scheme, which will cost firms £3,500 a year to join, include Marks & Spencer, Ikea, Tesco, EDF Energy, John Lewis, British Sky Broadcasting and Chelsea Football Club.

According to reports in the Financial Times, firms are also set to agree upon publishing the results of their efforts, a move that could see the worst performers effectively "named and shamed".

Separately, Livingstone is also poised to launch a Better Buildings Partnership together with 20 of London's biggest landlords. Under the new scheme, which will cost £10,000 to join, leading property companies will set targets for emission reductions across their portfolios.

A version of this article first appeared at AccountancyAge.com