Star Turn

Alison Utley sits in as the cling-film man of geology tells his Open University students how plant fossils can reveal the earth's climate of 100 million years ago

After a quick rub down with a towel following several drenchings on the third day of their geology summer school, Bob Spicer's audience file in to the theatre to experience their first formal lecture.

Not that it is all that formal. Before our distinguished guest has even arrived at the podium the overhead projector is showing a photograph of him wrapped in cling film. And we do not think that has anything to do with his research. Today at Durham University he is wearing the dinosaur tie that he often gets out when he needs to break the ice, as it were, with students. A former botanist, Professor Spicer now spends his days drilling ice in places like North Alaska collecting plant fossils, which he says hold the key not only to the earth's climatic history but also its future.

Apparently he can tell to within a few degrees what the earth's temperature was 100 million years ago. And he does not buy into the theory that the dinosaurs ended their days when a freak asteroid fell out of the sky. That is too easy, a Hollywood solution. His contention is that climate change did for the dinosaurs. Which, if boring, is still a little alarming given the current trend towards global warming.

"This is the only home we have and everything we do impacts on our planet,'' Professor Spicer tells us. "We are all a product of our past, we have not dropped here from a spaceship.'' A gentle reminder that our own ancestry, way before the small furry mammals stage, reaches back to blobs of protoplasm 3.5 billion years ago.

Professor Spicer has been given a difficult task. Explaining to Level 1 Open University geology students how the earth works in 60 minutes requires some bold editing, but with the aid of simple slides showing essential processes such as the carbon cycle we move effortlessly through the earth's various stages.

We understand how precisely vegetation reflects climate although we are told that it actually takes some pretty hairy mathematics to decode the correlation between leaf characteristics and weather.

There are impressive rotating graphics and even pictures of nearby Scarborough beach full of forests and dinosaurs as it would have looked during the Jurassic period. We also get a flavour of how global climatic modelling takes place, learning that today's models built to predict climatic conditions are "extremely unreliable''.

Then we find out that the world is now in an abnormally cold spell. It seems that for 80 per cent of the past 500 million years the world's temperature was warmer than it is today. The news brings relief all round.

Naturally Professor Spicer, who joined the OU from Oxford University as head of earth sciences in 1994, spends much of his time in far-flung places. He has stories, plenty of them, from surviving on a diet of dried fish and vodka, to planes running out of fuel in violent cross winds, and documents being confiscated by officials because they have never seen a British passport before. He even knows how to use a blow torch to burn the hair off moose lips in order to make soup. This was thrilling stuff. Indiana Jones eat your heart out.