Citigroup began tracking its virtualization efforts in January 2007. So far, 10 percent of Citi’s North American IT environment is virtualized, which saves the company about $1 million per year, Citigroup Green IT director Michelle Erickson told Computerworld.

The move has allowed the company reduce energy consumption by 73 percent and avoid about 300 tons of annual CO2 emissions.

Products certified for Citigroup’s data centers all have an 85 percent efficiency rating, according to Erickson. The corporation plans to have 50 percent of its global desktop environment populated by thin-client machines by 2010.

Citigroup is also working to reduce the number of data centers it has around the world from 52 in 2006 to 24 in 2010. In 2007, it had 37 global data centers.

Last year, Citi was awarded LEED Gold certification for a new skyscraper in New York.

In 2007, the company announced that it will direct $50 billion over the next 10 years to address climate change.