In what is a rare judicial ruling on what children can see in the class-room, Mr Justice Barton was at pains to point out that the “apocalyptic vision” presented in the film was politically partisan and not an impartial analysis of the science of climate change.

“It is plainly, as witnessed by the fact that it received an Oscar this year for best documentary film, a powerful, dramatically presented and highly professionally produced film,” he said in his ruling. “It is built around the charismatic presence of the ex-Vice-Presi-dent, Al Gore, whose crusade it now is to persuade the world of the dangers of climate change caused by global warming.

“It is now common ground that it is not simply a science film – although it is clear that it is based substantially on scientific research and opinion – but that it is a political film.”

The claim that sea levels could rise by 20ft “in the near future” was dismissed as “distinctly alarmist”.

Such a rise would take place “only after, and over, millennia”. Mr Justice Burton added: “The ar-mageddon scenario he predicts, inso-far as it suggests that sea level rises of seven metres might occur in the immediate future, is not in line with the scientific consensus.”

A claim that atolls in the Pacific had already been evacuated was supported by “no evidence”, while to suggest that two graphs showing carbon dioxide levels and temperatures over the last 650,000 years were an “exact fit” overstated the case.