Almost nine out of ten (86 per cent) IT departments do not measure their carbon footprint and less than 20 per cent even see their energy bills, according to green researchers.

And the growth in CO2 emissions from the sector is being exacerbated by regulations like Sarbanes-Oxley that require high levels of data to be stored for compliance reasons.

Office technology accounts for more emissions than previously calculated, according to Trewin Restorick, director of Global Action Plan, the charity that carried out the research.

"IT equipment currently accounts for between three and four per cent of the world’s carbon emissions, and 10 per cent of the UK’s energy bill," said Restorick.

"How businesses utilise technology will increasingly come under the spotlight," he said.

The survey of 120 UK IT departments found that more than 60 per cent of respondents consider time pressures and cost the biggest barriers to adopting sustainable policies.

And vendors are also confusing the issue, said Restorick.

"IT departments need help - they need vendors to give them better information rather than selling green froth," he said.