Organizers say over 300,000 people took part in the protests across Australia. Here, protesters march in Melbourne.
This photograph shows a huge crowd in a Sydney park.
It was tweeted by Kym Chapple, a politician for Australia's Greens Party.
The protests are led by school students, who started the movement this year by skipping school on Fridays to call for government action on climate change.
The students reject the common criticism that they should be in school.
Danielle Porepilliasana, a high school student in Sydney, said: "World leaders from everywhere are telling us that students need to be at school doing work. I'd like to see them at their parliaments doing their jobs for once."
Source: Reuters
Some protesters joked about how they were skipping school for the day.
The top 10 carbon emitters in the country also took questions from schoolchildren on Friday.
People of all ages — including babies, toddlers, teens, and adults — gathered across the country.
"I'm worried about the animals," 9-year-old Maeve, from Melbourne, told Business Insider.
"I'm worried about the ice melting which isn't very good."
In Thailand, people protested in front of the Ministry of Natural Resources and Environment in Bangkok.
They staged a "die-in," an attempt to symbolize the consequences of climate change. They also delivered a letter to the government calling on it to declare a climate emergency and phase out coal.
Students gathered on Marovo Island in the Solomon Islands — an island chain close to Papua New Guinea.
The Solomon Islands, located in the Pacific, are already experiencing the effects of rising sea levels, flooding, and erosion. Communities have had to relocate on these low-lying islands, and several reef islands have been lost to the sea.
Source: The Conversation
The protests are now spreading into Europe as the school and work day begins. Here, demonstrators block traffic in Frankfurt, Germany.
400 protests have been announced across Germany along.