Allen & Overy (A&O) has been named as the firm with the largest carbon footprint out of of a group of 18 UK firms that have chosen to publicly reveal their environmental impact.

Based on the Legal Sector Alliance's (LSA) newly-developed tool, dubbed the LSA Protocol, which enables law firms to make an estimate of the level of carbon dioxide emissions it is responsible for, A&O was responsible for 27,269 tonnes of CO2 – or 8.52 tonnes per employee.

Magic circle rivals Linklaters and Freshfields Bruckhaus Deringer were ranked second and third with total emissions of 20,848 tonnes and 16,270 tonnes respectively.

DLA Piper UK, Lovells, Eversheds, Herbert Smith, Slaughter and May, SJ Berwin and Taylor Wessing also also took part in the scheme, with their total emissions ranging from 12,037 tonnes to 3,185 tonnes of CO2.

Clifford Chance did not take part in the initiative.

The LSA said UK regional firms would produce less emissions as a result of having a largely domestic practice.

Meanwhile, the Law Society produced 4,105 tonnes of CO2, or 2.83 tonnes per employee.

The firms that took part in the study were founding members of the LSA initiative, which was launched yesterday (10 December), and aims to take action on climate change within the legal profession.