Ten-year-old Anna can’t decide whether she likes “blowing giant bubbles” or “making crystals” best of all. She’s spent an hour in the Science Museum’s newest gallery, enthralled by a machine that lets you squirt water across a freezing glass plate, then watch through a magnifying window as the fragile shapes of icy crystals form.

It’s an apt backdrop for Chris Rapley, the museum’s new director, who is being interviewed at the launch of the gallery, which is stuffed full of gadgets designed to stop children being switched off by physics.

For Rapley is fresh from his leadership of the British Antarctic Survey, where he looked on as penguins were displaced and ice sheets shrank. He is also talking about one of the most controversial issues in schools – the teaching of “climate change”, how fast the earth’s warming could result in fatal food and water shortages, and what people can do to delay a potential Armageddon.

“I have been called a climate change zealot. I am not a zealot, I am an expert,” says Rapley, a 60-year-old grandfather, who has suggested that population control – limiting the number of children per family – might be a helpful way forward.

“Nobody wants to scare kids to death about the future,” he says. “But the earth is responding to global warming more rapidly than most scientists, myself included, expected . . . Children need to learn that the world works on certain principles. There are laws of physics: we need to help them understand the consequences of our actions.”

Anyway, he adds, “They are interested in how their lives might change: should they recycle, should mum take them to school in the SUV?”

When the government made it compulsory this year for children to learn about climate change as part of the national curriculum the move infuriated many. In geography children may learn about global warming and rising sea levels. In science they can be taught about the need to reduce our dependence on oil and gas and harmful emissions from exhausts.

Enthused, many come home and urge their parents to recycle or switch to electric cars and energy-saving lightbulbs. But some critics say children are being indoctrinated with a theory that isn’t proven in all its detail.

Earlier this month private school heads dismissed the inclusion of climate change in the national curriculum as teaching “fashionable causes” and warned they would draw up an alternative syllabus. Michael Spinney, chairman of the Independent Association of Prep Schools, said: “The curriculum is being overwhelmed by a social agenda, [which] is not something we want to get sucked into.”

Some parents were incensed too. When ministers decided to send a copy of An Inconvenient Truth, Al Gore’s Oscar-winning film on global warming, to every school in the country, one Kent father, Stewart Dim-mock, worried about the possibility that children were being brain-washed, challenged the move in the High Court.

Mr Justice Barton ruled that the film could be issued to schools only if it was accompanied by what one education official called “a health warning”. While he accepted the main thrust of its arguments, the judge said the “political” film should come with guidance notes to highlight some “alarmist” scientific errors, mostly about the predicted impact of climate change.

Chris Woodhead is among those who think that making “a sexy topic of the moment” compulsory is a bad example of political correctness. “Children do not have the understanding to deal with complex scientific arguments. There is a danger they will be indoctrinated,” says the former chief inspector of schools.

“There are different views about the impact of climate change – and some scientists are hot and bothered because their views are being side-lined. It is wrong to expose children to possibly one biased and prejudiced view.”

Rapley is reluctant to get drawn into the schools debate but is determined to educate people via the museum about the facts and let them make up their own minds.

Even though he became director only this year he’s got a team working on a climate change gallery, to be opened in 2009. Exhibits might include chunks of Antarctic ice and even a penguin to remind people of the risk of losing our “last pristine wilderness”.

“In my previous job . . . when you gave people a 500,000-year-old piece of ice it was a powerful lesson: almost like a laying on of hands,” says Rapley. “I don’t think we can supply 500,000-year-old ice chunks to everyone. But something along these lines is what we are looking for.”

He wants the museum to be an authoritative source of information on climate change, both the sceptical view and the mainstream view. But, he adds, the risks cannot be ignored. “If I walk up to my aircraft with my granddaughter, and the stewardess says, ‘Welcome on board, but I must tell you that there is a one in 100 chance the wings will fall off’ then that is too high for a responsible grandparent to risk.

“But at one in 100 odds it is very plausible we will have changes in our planet by the end of the century: yet my granddaughter and all the rest of us are on Spaceship Earth. We have to take this seriously. We could wake up tomorrow and realise it is a big mistake. But all the evidence says that it isn’t.”

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