Peter Day reports from Aberdeen, where Britain's energy revolution began under the North Sea almost 40 years ago. Investment is up but production is down - so what's the future?

The headlines are full of energy shortages and the potential of UK onshore shale gas discoveries.

But what's happening in and under the North Sea where Britain's energy revolution began almost 40 years ago? Peter Day reports from Aberdeen.

There's record investment of more than 13 billion pounds this year in the North Sea oil and gas industry but production is down as the oil has become harder to extract. Aberdeen itself is booming: there is virtually no unemployment and it has become a global hub of technical expertise, with international firms specialising in the technology and equipment needed to extract the oil. The big oil companies are moving further away to the West of the Shetland Isles in search of large new fields while smaller entrepreneurial firms are exploring for, and producing, oil from the older fields. Meanwhile national oil companies from Korea and China are buying their way in through take-overs.

Producer: Caroline Bayley.