The long, low,windowless buildings housing corporate data centers look like environmentally benign slabs of 21st Century capitalism. With no smokestacks puffing clouds of smog into the air or drain pipes dispensing muck into rivers, they don't seem a ripe target for environmentalists.
But annual energy consumption from data centers in the U.S. exceeds that of 5.7 million American households, says a 2007 report from the Environmental Protection Agency (EPA). On a global scale, the energy used by data centers produces CO2 that exceeds that produced by all sources in Argentina, according to a 2008 McKinsey & Co. study.
Data centers, which are indirect emission sources, don't usually produce CO2 onsite. But they suck power on many levels--from massive cooling structures that keep computer servers from overheating to the huge amount of energy they need to keep the servers buzzing
24 hours a day.
Along with the focus on indirect emission sources comes a pressure on companies to self-report their carbon footprint. "Socially responsible investors, nongovernmental entities and, at some level, eventually the regulators will look at the reports and say, 'Are you doing what you're supposed to be doing?'" Kahn says.
"If we're going to do a cap-and-trade system, then we're going to allocate carbon credits to specific industries and then require them to ratchet down their emissions over time," Benfield says. "People haven't looked at data centers as one of the larger consumers of those credits, but we need to look at where those emissions are really coming from."