Making a five minute call on your mobile phone uses the equivalent amount of carbon as boiling water to make one cup of tea, the first footprint assessment of mobile phone services has revealed.

Telecoms giant O2 has calculated the greenhouse gas emissions embedded throughout the entire lifecycle of its voice and data services to come up with the figure.

It also worked out that a one minute phonecall produces 3.6g CO2 equivalent, while transferring one megabyte of data generates 11g of CO2e.

The work formed part of O2’s successful bid to become the first mobile network operator to have its carbon footprint independently verified by the Carbon Trust.

A separate study conducted by the Trust found limited public awareness of the environmental impact of mobile networks, which has prompted O2 to start developing a tool to help customers calculate the CO2 emissions associated with the services they use and provide comparisons with various activities.

“Our aim is to develop the UK’s most carbon-efficient network, putting our own operations under the microscope and looking for ways to reduce the footprint we leave on the world,” said Gareth Rice, head of environment at O2, adding that the detailed assessment of its footprint would help the company identify areas where it can curb emissions.

According to the new study, energy consumption and associated greenhouse gas emissions from mobile services make up the majority of O2’s carbon footprint.

The company is now looking to deliver deep cuts in emissions as part of its sustainability plan, Think Big Blueprint, which was unveiled earlier this year and sets a goal of delivering carbon savings to customers that are 10 times the impact of the network by 2015.