IDC has published an ICT Sustainability Index to measure the effectiveness of countries to lower their carbon footprint by using smart IT.
Roberta Bigliani, research director at IDC Energy Insights, said: "The use of software solutions offering energy management systems should be a key focus for all of the G20 nations."
IDC said that energy management systems and intelligent building designs offer the most opportunity of all technologies, or nearly 12% of all G20 energy savings. Microprocessors can also be used to make electric motors run more efficiently.
The results of the ICT Sustainability Index showed that Japan was the leading G20 nation by a considerable margin over the United States (2nd), while Brazil, France, Germany and the United Kingdom tied for third place. Other national rankings included South Korea (11th), China (12th), India (13th), Russia (15th), and South Africa (19th).