The focus on carbon emission reductions is often on manufacturing or the transportation sector. But the growing services industry has its effects on the planet, too. Large consulting and accounting firms have employees around the globe who fly to client sites week after week. Add energy-hogging data centers to the mix. Then you have office space rented where lights and computers are humming around the clock.

Nevertheless, professional services firms are doing their part to mitigate their impact on the environment. Accenture has transformed its travel policy and implemented firm-wide energy efficiency programs, which reduced its per-person carbon emissions by 25%. PricewaterhouseCoopers has done its part, too: the firm has reduced its greenhouse gas emissions this year by 20% from its 2007 levels.

That reduction is impressive when one considers that PwC had worked to achieve that goal by 2010.  Travel, a huge part of PwC's operations, was instrumental in achieving the firm's goals. PwC held more virtual events and ramped up video conferencing. The results are impressive: a 30% reduction in total flight segments booked by employees, and a 27% decrease in total miles flown.

PwC also invested in $5.7 million in energy audits at its largest properties, resulting in those offices’ collective 18% reduction in energy consumption. Its newest data, which opened this year, is LEED Gold certified. But the firm does not only focus on big energy efficiency projects—PwC has set up “green teams” in over 50 offices, which remind employees of initiatives to a reduction in disposable cup use to a policy of double-sided printing in its offices.

None of this should be a surprise, as PwC has had a climate change and sustainability practice based out of its Toronto office for 15 years. The firm has advised firms of the connection between sustainability and financial performance since at least 1999. PwC has also suggested that companies plan for the long term, rather than just a focus on one- to five-year growth plans.  So essentially PwC argues that it practices what it preaches: the firm employs over 700 climate change and sustainability professionals, and has purchased other advisory firms to add to a division that has actively worked with clients on sustainability issues since the late 1990s.

Of course it is always easy to focus on the environment, but the PwC also has rigorous programs for the communities in which it operates: its firms’ employees together donated $30 million to local programs and logged over 130,000 hours of volunteer work.  Mindful that engaged employees are productive and save the firm money if they do not leave, PcW launched several leadership and employee development programs, too.

I’ll leave it to PcW and Accenture to slug it out who is the more “sustainable” organization.  Both have succeeded in putting their money where their mouths are.  As they say, competition on the marketplace is a good thing.