Better use of computer and communication technology could reduce global carbon dioxide (CO2) emissions by 15% by 2020 and save businesses £500 billion ($800 billion) a year, says a report from The Climate Group and the Global e-Sustainability Initiative.

The sector's carbon footprint currently represents 2% of global emissions and will almost certainly double by 2020, according to the report's analysis by consultants McKinsey & Co. For instance, personal computer ownership will quadruple between 2007 and 2020, to 4 billion devices, and emissions will double over the same period.

But a “unique ability to monitor and maximise energy efficiency both within and outside of its own sector could cut CO2 emissions by up to five times this amount” – representing a saving of 7.8 billion tonnes by 2020, the report says.

The greatest opportunities for emissions savings lie in applying information and communication technology (ICT) to global infrastructure and industry. The report identified four major opportunities where ICT can help improve energy efficiency: industry electric motors and industrial automation; logistics; buildings; and grid technologies.