The scientific consensus that humans are contributing to climate change is likely to have passed 99%, according to the most authoritative study on the subject. So naturally, schools are largely now teaching climate change as a scientific fact.
But one father in Australia isn't happy with his son being taught about the topic, accusing staff of brainwashing children.
Matthew Karlos told A Current Affair that he's infuriated that climate change is being taught in schools, claiming "it's ridiculous, absolutely ridiculous."
Karlos says he pulled his son out of school when teachers asked his 10-year-old son Max to "dress up as hippies, and sing this song, big yellow taxi."
Max went on to add: "We shouldn't be worrying about the end of the world."
Karlos agreed with his son, adding: "It's just brainwashing the younger generations."
"They shouldn't be teaching kids that, and yeah we shouldn't toss away our rubbish as I said before, but we shouldn't be worrying about the end of the world," Max said.
When Max learned that the last day of the term would be a 'Greenie day' it was the last straw for the pair.
"All the other kids, 'cause we were all in the one class at the time, they were all going, 'yay we can dress up as hippies', and I just said', what's so good about it? There's nothing good about them,'" Max said.
"They just sit around doing nothing all day."
As well as dressing up, students were asked to sing to the environmental song Big Yellow Taxi, written by Joni Mitchell.
Karlos had already kept Max at home when students were asked to give a speech on the environment weeks prior.
"It was to do with mankind induced climate change and all this business they carry on about now," he said.
Karlos admitted that as a water farmer, he's had issues with climate activists who oppose his water harvesting business.
"They don't like the trucks on the road, they don't like this, they don't like that you know, so here we are," he said.
So, he's decided to pull Max out of school. Karlos said:
"You've gotta (sic) teach kids to be happy and positive and it's all well and good to be concerned about the environment and wanting to teach kids good practices and basically not be grubs and throw litter around and this sort of thing, but you don't have to be a greenie to do that."
A report from the Intergovernmental Panel on Climate Change (IPCC) warned last month that 280 million people could be displaced by rising sea levels if global temperatures rise to 2C above pre-industrial levels. The report also said that millions would be at risk of drought and famine as a result of rising temperatures.
The climate emergency has been highlighted in the last year by 16-year-old Greta Thunberg. The teenager has been skipping school every Friday for the last year to strike outside the Swedish Parliament building and demand that the government does more to combat climate change.
During a global Climate Strike in September, more than 4 million people took to the streets with Thunberg to demand change.
The climate activist also spoke to world leaders during the UN Climate Action Summit in New York, saying:
“With today’s emissions levels, our remaining CO2 budget will be gone in less than 8.5 years."
"We are in the beginning of a mass extinction and all you can talk about is money and fairy tales of eternal economic growth. How dare you?"
"You have stolen my dreams and my childhood with your empty words and yet, I'm one of the lucky ones. People are suffering, people are dying."
“You are failing us. But the young people are starting to understand your betrayal. The eyes of all future generations are upon you. And if you choose to fail us I say we will never forgive you. We will not let you get away with this. Right here, right now is where we draw the line. The world is waking up. And change is coming, whether you like it or not.”
Karlos is one of many adults who has been critical of Thunberg, saying: "The fact that you've got supposed adults ... pushing ideas on a 16-year-old girl and using her as a pawn, is just disgusting; it's child abuse."
"Just stop brainwashing the kids and being negative and teach them how to be positive about making good positive changes for the world, not all doom and gloom."
In a statement, a spokesperson for the New South Wales Department of Education said, "studying controversial issues is acceptable for educational purposes."
Max will start at a new school when the next term begins.