US President Donald Trump has told the UN General Assembly that climate change was “the greatest con job ever perpetrated on the world”.

Speaking at the global assembly in New York on Tuesday (Wednesday AEST), he dismissed previous predictions about climate change leading to global catastrophe.

The vast majority of climate scientists have concluded climate change is happening, and that it is mainly caused by fossil fuel pollution.

The world is already experiencing the impacts: floods are more severe and lethal, droughts are increasingly widespread and intense, and heatwaves are becoming perilous.

But Trump refused to be swayed and dismissed the scientific evidence.

“All these predictions from the United Nations and others, often driven by dubious motives, were incorrect,” Trump remarked. “They were made by foolish individuals.”

“They claimed global warming would devastate the planet, but then temperatures started to cool. So now they call it climate change, allowing for any scenario to fit. It’s labeled climate change because whether temperatures rise or fall, it’s all encompassed by climate change.”

The US president also claimed green energy policies allow countries without restrictions to make money.

“These harsh green energy policies primarily haven’t benefited the environment but have shifted manufacturing and industrial activity from developed nations adhering to these absurd rules to polluting countries that bypass them and profit,” Trump stated.

He further criticized the concept of a carbon footprint, or the greenhouse gas emissions produced by individuals or entities, as a “deception,” asserting that advocates for reducing it, like former US President Barack Obama, were acting hypocritically.

“The carbon footprint is a hoax made up by people with evil intentions, and they’re heading down a path of total destruction,” Trump said.

“A few years ago, I remember hearing about the carbon footprint, and then President Obama would get into Air Force One, a massive Boeing 747, and not a new one, an old one with old engines that spew everything into the atmosphere.”