For Linklaters, the event saw the launch of the 'Change One Thing' six-month challenge for all its employees, with a dedicated website for its staff to make their pledges.
As part of the scheme, partners and senior associates vowed to cycle into work, to use a mug instead of throwaway cups and even to take their biodegradables home to put on their compost heaps.
The UK base and several international offices also watched Al Gore's documentary on the state of global warming, An Inconvenient Truth. This was preceded by a film of senior partner David Cheyne talking about what climate change means to the firm.
Eversheds marked World Environment Day with a week of green activities, including housing a fair trade market in its café . The firm also embarked on a 'big switch off', which is similar to Linklaters' 'switch off campaign'. As the titles suggest, these schemes encourage people to turn off their lights and computers when they leave the office each day.
Eversheds and Simmons & Simmons also offered 'no air miles food' in their staff restaurants. The Simmons event included a map so people could see exactly where their dinner had come from.
Simmons and Clifford Chance managed to persuade their staff to get a little greener by holding green-themed competitions with eco-prizes. Nearly a third of Simmons' London office took part.
Norton Rose climate change partner Antony Hobley chaired an investment conference in Westminster to mark the day. A Norton Rose spokesperson said the firm's lawyer's were also shown the Al Gore film and Norton Rose mugs were handed out in an effort to avoid using disposables.
DLA Piper tried to get its staff to consider how they could support the environment by inviting them to make a pledge to change their work pattern. Some pledges were as simple as double-sided printing, but one brave person decided to use the stairs instead of the lift to get to their eighth-floor office.
Hammonds used World Environment Day to launch its environmental policy on the firm's intranet. The firm is committed to reducing its energy consumption by 10 per cent in the next two years and reducing its paper waste by a tenth in the next 12 months.
Law firms' efforts to mark World Environment Day follow the decision of several firms to commit formally to reducing their carbon footprint over the past six months.
Linklaters is pushing its employees to become carbon neutral and Norton Rose has challenged its staff to shrink their own carbon footprints by 10 per cent.