Local high school students managed to catch up with Tony Abbott in a cafe today to confront him on his stance on climate change.

Mr Abbott is believed to have left his Manly office through a back door to avoid a school climate strike attended by about 500 people, mostly primary and secondary students and their supporters.

But Elsie Loadman and Yasmin Lin, both aged 15, caught up with Mr Abbott in a cafe and told him they thought climate change was a critical issue that required action.

"The problem is, everything you do has a cost," Mr Abbott said.

He also noted the climate was always changing and "the ice age was climate change", although he acknowledged that mankind does make a difference.

"The Earth has survived many things … I don't believe that modest increases in atmospheric carbon dioxide concentrations over the new few decades are bound to bring about the kind of environmental catastrophe that you seem to fear," he said.

Both the girls said it made the angry to hear Mr Abbott's response.

"I was so mad I couldn't speak for a period of time because I couldn't register what he was saying," Yasmin said.

Elsie said Mr Abbott wasn't listening to the science.

"He isn’t listening to our community, and he isn’t serious about climate change," she said.

“I’m really scared my generation, and the generations after me, will pay a high price for a lack of action on climate change now. It's only going to get worse if we don't take action today."

The protest in Warringah, which drew about 500 students, was part of a number of strikes held across Australia today to demand action on climate change.

Thousands of students held strikes in 75 locations, many outside Federal MP offices.

More than 1000 students also sat down in front of Liberal Party HQ in Melbourne and there was also expected to be a rally outside Treasurer Josh Frydenberg's office.

In Sydney, more than 100 chanted outside PM Scott Morrison's office and 500 made a racket with kazoos outside Labor MP Anthony Albanese's office in Sydney's inner west.

There were also rallies in Brisbane, Perth, Adelaide, Canberra and Newcastle.