"The cost in energy around the world varies, but the trend in unit cost per kilowatt hour is going up, and it's going up way ahead of inflation. That's pretty universal, and it's increasingly a point of contention," Gartner's Mingay says. "In the US, [cost of energy] is the most important driver. It's maybe 80/20, cost savings or cost avoidance vs. carbon footprint. In Europe, it's 60 per cent about cost savings and 40 per cent about carbon reduction."

How much pressure CIOs are under to reduce their carbon footprint depends on their industry. In a manufacturing business, where IT might count for 1 per cent of total carbon emissions, there's not as much pressure as there is on a Web portal where IT is the business.

"For knowledge industries, like financial services, banking, pharmaceuticals and the public sector, IT is going to be a much bigger portion of carbon footprint and more of a focus of attention," Mingay says. "We think the need for action on climate change will increase significantly in the US over the next two to three years. This will be a pressure on CIOs to be contributing toward carbon reduction."

Acumen's Stanley says the pressure on CIOs to reduce their carbon footprint because of a CEO-initiated green initiative is less than the pressure to maximize their data center footprint and keep electricity costs down.

"The biggest pressure on IT executives is data center footprint. That's No. 1," Stanley says. "Cost savings and energy efficiency is No. 2, particularly from a hardware perspective. Being green is a distant third as far as motivation is concerned."

For now, "the green that they are focused on the IT side of the house is the color of money," Stanley adds.

4. Lawmakers

In Europe, with its cap-and-trade program for greenhouse gases, the pressure on CIOs to measure and reduce their carbon footprint is real. But in the United States, the regulatory pressure on CIOs is considerably less because comparable legislation doesn't exist here.

"Based on potential changes in Congress, there may be some form of regulation," says Erik Teetzel, renewable energy manager at Google. "The fact that this administration is ending may encourage people to start taking inventory of their emissions" before regulation passes.

Teetzel says most CIOs don't feel pressure to adopt green IT practices created by lawmakers yet. But forward-looking companies such as Google are identifying areas where they can cut back on their carbon footprint whether or not legislation is passed.

"People will get ready for action" related to regulatory compliance, Teetzel adds.

"Some organizations are looking at this in terms of acting now so that if and when there should be any regulation, they are in a better position to respond," Gartner's Mingay says. "Since there's no mandate, this is more of a risk avoidance than an actual pressure."