The government has released details of plans to make its computer systems carbon neutral by 2020.

Whitehall's computer systems are responsible for 20 percent of all its carbon emissions and it's hoped that small measures such as switching off PCs at night and offsetting schemes that involve buying carbon credits will save 117,500 tonnes of CO2 per year .

Other measures in the 18 key steps include re-using as much computer equipment as possible and making sure servers are not idle.

According to Cabinet Office minister Tom Watson, computers are responsible for as much carbon emissions as the airline industry.

"That's why I'm so proud that we are the first government anywhere in the world to formally set out exactly what we're going to do to make our ICT systems carbon neutral within four years" he said.

See also: 11 easy ways to turn your PC green

Public sector IT must go green, says minister