The rapidly growing carbon footprint associated with information and communications technologies, including laptops and PCs, data centers and computing networks, mobile phones, and telecommunications networks, could make them among the biggest greenhouse gas emitters by 2020. However, our research also suggests that there are opportunities to use these technologies to make the world economy more energy and carbon efficient. An analysis of five groups of abatement opportunities finds that such technologies could help to eliminate 7.8 metric gigatons of greenhouse gas emissions annually by 2020 (Exhibit 1)—equivalent to 15 percent of global emissions today and five times more than our estimate of the emissions from these technologies in 2020.

To calculate their carbon footprint—what it was in 2002 and 2007, and what it will be in 2020—we looked at the level of emissions associated with their use of energy and with their manufacture and distribution. We used standard industry estimates for growth in the number of computers and peripherals, data centers, and telecommunications networks and devices. Then we estimated the power usage of today’s and tomorrow’s installed base of these technologies, factoring in improvements in energy efficiency that could appear during the next few years, as well as current and...