Former climate activist Michael Shellenberger has condemned alarmists for “terrorising school children” with false claims that the world is about to end.

The life-long environmentalist has given Sky News host Chris Kenny a lengthy interview about his decision to speak out against the alarmist rhetoric which he says is creating anxiety in young people.

“I have a 14-year-old daughter and she is fine because I’ve explained the science to her (but) her friends are very alarmed,” he said.

“Adolescents these days have a lot to worry about, anxiety and depression are rising among everyone really, certainly adolescents, and I thought it was not right to be terrorising school children and giving them false information.”

Shellenberger - who has been invited to be an expert reviewer to the UN’s Intergovernmental Panel on Climate Change - maintains that climate change is occurring but says it is not a “catastrophic threat”.

He says the science has been hijacked by a “handful” of activist scientists who are spreading “science fiction”.

“The majority of scientists are not activists, there are actually only a handful of scientists who feel the need to terrify people,” he said.

“I don’t think this is really that complicated, we need to lift everybody out of poverty, and we need to do our best to preserve natural places and things have just spiralled out of control.

“This climate change thing has just got too crazy.”

Shellenberger said he had noticed a “dark tradition” of anti-human rhetoric spilling from climate change activists, including views that humans were a “cancer” or a virus.

In the second half of the interview – which will air on Sky News Australia on the Kenny Report at 5pm on Thursday night – Shellenberger also weighs into whether climate change was a significant cause of the Australian bushfires.

“Yes there is evidence of that,” he said.

“However, It is massively outweighed by two factors; the accumulation of wood fuel in the forests and the development of new houses near forests.

“Is there some contributing role of climate change? Yes. Is it very significant? No”.

Alex Epstein interviews Michael Shellenberger, author of Apocalypse Never, which hit #5 on Amazon. His recent article, "On Behalf Of Environmentalists, I Apologize For The Climate Scare," has been widely shared.

Some highlights:
* How Shellenberger went from being a renewables activists to championing nuclear.
* Why Shellenberger decided to stand up against climate catastrophism after years of silence.
* How modern environmentalism is a religion.
* The real motives of most of modern environmentalism.
* How environmental journalists misrepresent environmental science.