Amanda Gillies, Duncan Garner clash over 'mocking' Greta Thunberg

The AM Show newsreader Amanda Gillies has clashed with Duncan Garner on-air over teen climate activist Greta Thunberg.

Thunberg, 16, gave an emotional speech to the United Nations Climate Action Summit this week, blasting world leaders for their inaction on climate change.

Garner questioned Thunberg's tone at the event, which he said was too dramatic and distracted from her message.

Sportsreader Mark Richardson agreed and joked she needed a backing track when a clip of it was played on The AM Show on Thursday.

"Honestly the only thing lacking from that theatrical performance was the whole place spontaneously busting out a rendition of 'The Children Are Our Future'," Richardson said.

Garner, knowing Gillies wouldn't be pleased, told her she could challenge Richardson if she wanted and she wasted no time telling him off.

"You know how I feel about this and I don't think we're winning at all by mocking her, especially in mental health week, I mean come on guys... You can't pick on a 16-year-old girl. 

"We should be embracing this. If she's going to stand up, a 16-year-old woman on the world stage and hold leaders to account, good on her."

But Garner became embroiled in the debate when he stuck up for his opinion, saying Thunberg was fair game. Gilles still wasn't convinced.

"She's putting something which is a huge issue in our world, which will affect your children your grandchildren and so on, why mock her?

"Just say 'good on her', listen to her."

Finally Garner tried to clarify nobody is mocking Thunberg, instead, they're questioning her delivery. But Gillies remained unconvinced it was the right course of action.

"That's just the way she talks... she may have just gotten a little bit excited she had the audience there, and I say embrace it, encourage her, she's impressive."

Garner said after that it was time to "draw the line" on the conversation and the group moved on to discussing The AM Show's daily poll results.

Newshub.