I remember some time ago someone telling me that doing a Google search used more energy than boiling a kettle. I was unable to verify this  so I’ve never used this ‘fact’. However, there now appears to be some evidence to support this and similar claims.

A study by Ademe, the French government energy savings agency, says that using email rather than paper might be saving trees but is hardly saving the planet. Each email sent uses about 19g (0.7oz) of carbon dioxide and group emails can increase this figure by 400% while adding a photo attachment could increase it 1000%.

The study also claims that a company with 100 staff generates almost 14 tons of carbon dioxide, which is roughly equivalent to 13 return flights from Paris to New York. This calculation assumes that each member of staff sends 33 emails per day, which creates 136 kg (300 lb) of carbon dioxide. The data factors in the energy required to make the computers and also emissions from data centers.