Ernst & Young cut its carbon footprint in North, Central and South America by 15 percent in fiscal year 2009, the result of its efforts to use less energy and make its supply chain more environmentally friendly.

The company, part of the Big Four accounting and professional services firms, reduced its electricity consumption, business travel and server use in FY 2009, compared to the same period a year before.

It specifically used 22 million kilowatt hours less energy in its offices, while its workers flew 75 million fewer miles, or 18 percent. In its data centers, 1,453 servers were whittled down to 215.

As a result, its Scope 2 emissions from energy consumption, which account for 38 percent of its total carbon footprint, shrank 13 percent. Indirect Scope 3 emissions covering business travel fell 16 percent; total Scope 3 emissions are responsible for approximately 62 percent of its total emissions.

All of these efforts are part of a larger environmental sustainability program that also includes goals for supply chain, waste reduction and recycling, and meetings. For example, all of its requests for proposals exceeding $250,000 include solicitations for environmental impact information. The company's disposable cup program has cut consumption in half.

By 2012, Ernst & Young wants at least 30 percent of its U.S. square footage to be in LEED certified buildings.

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