As a scriptwriter, I have met lots of powerful people, but my reaction is always the same. When I went to the Oscars, I sat next to a pleasant, elegant woman and chatted happily to her until somebody pointed out it was Claudia Schiffer. After that, I could not utter another word.

But today it isn't because I am star-struck that I am terrified; it is because the oil man is telling me the opposite of everything he should say. Over the tinkle of teacups, he is predicting the end of civilisation.

My friends give me uncomfortable looks about my new film, Burn Up, because I have a Cassandra-like reputation for writing fiction about things that later become fact.

Many years ago, I made a film called The Darkest Light about a foot-and-mouth disease outbreak. Two years later, it happened for real.

I wrote the script for another film called Yasmin that suggested disaffected British Muslim youths could turn to terrorism. A year later came the London suicide bombings.

I'm not boasting: I just listen to experts who prove frighteningly accurate.

Burn Up - starring Rupert Penry-Jones, who played Adam Carter in the hit BBC series Spooks - is about the moment runaway climate change collides with an unprecedented oil crisis. So given my track record, my friends are keen to know what happens at the end.

Once I had decided to write a drama about climate change I spoke to everybody who was prepared to talk.

Surprisingly, this turned out not just to be the usual environmental suspects such as Greenpeace, Friends Of The Earth or WWF, but people in the oil industry.

And these weren't disaffected whistle-blowers, but some senior figures who were prepared to step out of the shadows and tell me just how scared they were.

The oil man predicting an apocalypse was one of them. I had gone to his office expecting him to tell me global warming was at best an uncertain science based on dodgy data, at worst a Left-wing conspiracy designed to tax us all to death.

Oil companies pumped out the oil that was producing the carbon dioxide, so why would he tell me any different?

Sure enough, that's how the interview started. The world was 'going through a 40-year transition period from a carbon economy to a hydrogen economy' where oil would smoothly be replaced by other sources of renewable energy.

He talked on convincingly. The tea-lady brought round the trolley. I felt reassurance waft over me: the environmental scaremongers were wrong.

Then I looked up. A '40-year transition period'? I cleared my throat, and nervously suggested that Sir John Houghton, the scientist who led the first Intergovernmental Panel On Climate Change, had told me we had at best ten years to stop the increase in global temperatures, otherwise we were in danger of runaway climate change. Ten years tops. Not 40.

The CEO stopped in his tracks. 'Oh, you've talked to him, have you?' His tone changed.

He sat down heavily and said: 'Well, I know John and he's right, and if you want to know what I really think, I think we're fiddling while Rome burns.' He was the first of many to come to the confessional. People who for the sake of their careers shouldn't even have returned my phone calls were opening their hearts to me. Why such dangerous honesty towards a writer?