Existing only in the digital sphere but currently worth a fortune, it is the virtual currency that has gone mainstream in recent weeks.

However, it has emerged that the production of bitcoins uses so much energy it threatens to seriously harm the planet.

In recent months investors have flocked to the currency that exists only in cyberspace and is traded directly from person to person.

But its very success had led to fears about the environmental impact of the Bitcoin phenomenon.

The process by which the currency is produced in the digital world - known as mining - uses an enormous amount of energy, much of it coming from the carbon fuels that cause the most pollution.

Total electricity use in bitcoin mining has increased by 30 percent in the past month, according to accounting firm PwC.