This week business and political leaders are meeting for the United Nations Conference on Sustainable Development – dubbed ‘Rio+20’.

Rio+20 marks the 20th anniversary of the 1992 United Nations Conference on Environment and Development, and the 10th anniversary of the 2002 World Summit on Sustainable Development. Taking action on climate change and preserving our natural resources is an ever more important imperative, which the UK is committed to under the Climate Change Act. The UK was the first nation to create a legally binding long-term framework to achieve our low-carbon economy ambitions. However, businesses must demonstrate continued leadership on the issue of sustainability if our 2020 and 2050 greenhouse gas reduction targets are to be met.

The first half of 2012 has been an interesting period for climate change policy in the UK, with the Department of Energy and Climate Change announcing a last-ditch attempt to simplify the widely criticised CRC Energy Efficiency Scheme, designed to encourage improvements in energy efficiency. George Osborne announced that the CRC will be scrapped and replaced with a less complicated green tax system if it cannot be simplified in the coming months.

Although the CRC only affects the largest law firms, it is likely that the threshold for compliance will be lowered incrementally, thereby capturing small and medium-sized businesses and an increasing proportion of the legal sector. The Department for Environment, Food and Rural Affairs yesterday announced the introduction of mandatory carbon reporting for publicly listed companies and it is likely that this requirement will be extended to impact law firms in the coming years, given its widespread industry support.

Law firms that have already measured their carbon footprint are well placed to meet any reporting obligations, as well as capturing significant efficiency and cost savings. The Legal Sector Alliance (LSA), an inclusive movement of law firms committed to working collaboratively to combat climate change by reducing their carbon footprint and adopting environmentally sustainable practices has, among a host of practical initiatives, developed a Carbon Reporting Tool to help law firms measure their carbon footprint.

The LSA, launched in 2008, now has more than 240 member firms, representing over a third of private practice solicitors in England and Wales. Acting on climate change is in our collective interest, and a greater impact can be achieved through collaborative action and the sharing of knowledge and experience. The LSA has developed a set of principles that, through widescale adoption, are enabling the legal sector to respond positively and collectively to climate change, by reducing its own carbon footprint and influencing key stakeholders to reduce theirs. The principles are appropriate to law firms of any size, specialism or location.

Last month the LSA reported a total reduction of almost 35,000 tonnes of carbon dioxide by its members in 2011, which is double the reduction achieved in the previous year and equivalent to the annual emissions of two magic circle law firms. Over 80% of firms achieved an absolute reduction in carbon emissions, and the average carbon emission per employee also decreased significantly, despite headcount reductions in 2011.

The carbon performance of the LSA executive members was particularly strong, with an average reduction in total carbon emissions of 18% over three years, up from an average of 12% over the previous three-year reporting period. As well as being the right thing to do, taking a positive approach to climate change is also advantageous in terms of relationship-building and generating business. Clients are increasingly requesting information on environmental policies and practices when appointing legal advisers, and the brightest young solicitors want to work for a firm that takes its environmental responsibilities seriously.

By taking positive action in a few key areas, minimising energy and resource use, firms can demonstrate environmental responsibility, and collectively the legal sector can make a significant contribution to addressing climate change. All the materials prepared by the LSA are free to use by any Law Society member through the alliance website.

Desmond Hudson is chief executive of the Law Society