BT has announced that it will cut its carbon emissions intensity by 80% across the globe by 2020, setting what it's describing as one of the "most aggressive" corporate carbon reduction targets worldwide.

BT chairman Sir Michael Rake said: "BT has a proud history of international leadership in carbon reduction and of setting and achieving challenging targets. We are delighted to raise the bar by extending these commitments to cover our entire global footprint, across more than 170 countries worldwide".

The telecoms company says it intends to meet the 80% reduction target through a continued combination of energy efficiency, on-site renewable generation (aiming for 25% of its UK electricity to come from dedicated wind turbines by 2016) and purchased low-carbon electricity.

A new model for measuring and tracking carbon emissions – backed by the Carbon Disclosure Project - will help monitor progress. BT claims to have already reduced emissions in the UK by nearly 60% between 1996 and 2008.