They ranged from witty to poignant to heartbreaking.
The signs — many made by children — spelled out the fears and frustrations held by many young Australians about perceived inaction on climate change.
Organisers estimated 300,000 Australians took part in climate change rallies across the nation on Friday.
While the demonstrators' demands and concerns were serious, many used the day to make funny, 'punny' and satirical signs and placards, while others weren't afraid to reveal their fear about what they see as an existential threat facing the planet.
Here is a collection highlighting some of the sentiments expressed by children and young adults at marches around the nation.
