Teetzel says this phenomenon has occurred at Google, where employees have organized into green teams.

There's more to employee efforts than "just putting stickers on desktop computers left on all night that say, 'Thanks for wasting electricity,'" Teetzel says. "Employees have a lot of debate and discussion...related to climate change."

One way that employees are driving action is through carbon-reduction competitions such as Carbon Rally.

Employees have "the potential to have the largest impact," Smith says. "Like all corporate processes, it's when you push them as far down into the field as possible that you get all these incredible results."

Smith says Digital Realty's employees are driving the company's efforts to have its data center buildings certified as green through the Leadership in Energy and Environmental Design (LEED) process.

"Once I explained LEED to our operations and construction teams, they took it from there. They are finding LEED points from other parts of the business," Smith says. "It's the same thing with consumption, performance and metering. We're trying to push that as far out into the field as possible."

10. The community

Community leaders are starting to apply pressure to local corporations to improve their sustainability. Although that's not a big pressure on CIOs today, these efforts are likely to increase.

"Cities, churches, nonprofits -- I do think that is a growing source of pressure with respect to people thinking a bit more about this topic," Teetzel says.

For example, the Climate Savers computing initiative has signed up the US states of Oregon, Colorado and Minnesota for energy efficiency collaborations. Under the terms of these agreements, the states will improve the energy efficiency of their own IT operations but they also will promote such concepts as buying Energy Star equipment and turning it off at night to the companies doing business in their states.

In fact, the US National Governors' Association partnered with Climate Savers last November to encourage the deployment of energy efficient computers and IT practices in US state government offices.