You’re on a plane, heading off on holiday. You stand in line, holding a pair of two litre milk cartons, filled with aviation fuel. As the queue moves forward, you ready yourself, and when you get to the front you have one second to empty them and then race to the back of the line to refill. That’s the rate at which a 747 or Airbus gets through fuel. “I was amazed to hear that” nine year old Katla told me afterwards.

Getting the climate change message across to children requires something they can visualise or directly relate to their own lives. Dr Hugh Hunt of Cambridge University and the Cambridge Climate Lecture Series is speaking to year five children at Rosendale Primary School in Dulwich. He’s come armed with film clips, farts and a willingness to field whatever questions these nine and ten years can throw at him.

“Who’s ever let out a fart that was silent and didn’t smell? Did you own up to it?” asks Hugh. These are emissions. “Cows fart a lot and they fart a gas that causes climate change. Who’s vegetarian or thinking about being vegetarian?” A good few hands go up, many more than would have a few years ago. Grace, aged nine felt vindicated. “The day before, in class, we were talking about causes of climate change and I said cow’s farts. No one believed me but they believed him” she explained.

“Who’s heard of a chap called Donald Trump?” brings on a chorus of boos. “There’s one good thing about Donald Trump” he continues. “Nooooo” shout the kids. Trump is doing such terrible things about climate change that all of a sudden people are getting very angry and saying ‘this is not what we want’. There’s a silver lining to every cloud.

“Who like mangoes?” Ninety hands shoot up, along with Hugh’s own. He then explains the environmental cost of transporting them to England. I spoke to ten year old Rachel afterwards, who worried, “so mangoes are bad?” Mangoes are great. Of course they are. It’s how they are brought here and how many millions we consume in Britain that’s the problem. A recent article in the Telegraph shows that M&S alone sells more than eight million a year. About 7.5 million of them are sliced and packaged in Brazil and then flown to the UK, while whole mangoes can be shipped.

The Rosendale children very quickly had hands raised to ask questions. How is climate change bad? Can using carbon fibre to make planes help? Will we evolve to cope with climate change? Even, why is beef called beef? Every question received a serious reply, even the more off the wall ones.

Every thing we do contributes to climate change, what we eat, when we travel, the stuff we buy. The amount of CO2. a household produces is about forty times the amount of rubbish (recycling and other waste). The message to the kids was to think about how you can make a difference. “We are all in this together” said Hugh. That’s not in a George Osborne, austerity Britain way. “The talk was brilliant” said Jasper, aged 10. Will it change your family’s behaviour? An emphatic “Yes!”

hugh hunt rosendale school