Millions of people all over the world are taking to the streets in what could be the largest climate protest in history.
In Northern Ireland, crowds have gathered at Belfast City Hall to make their voices heard amid the growing movement calling for action to address environmental concerns.
Children and young people are proving to be the driving force, walking out of schools and lectures as part of a snowballing movement.
It was sparked by teenage activist Greta Thunberg’s school strikes outside the Swedish parliament.
Friday’s protests come ahead of a climate action summit in New York convened by UN secretary general Antonio Guterres to urge countries to up their efforts.
In London, Mayor Sadiq Khan said: “It is unbelievable that we should need global strike action for the future of our planet to be taken seriously.
“The stark reality is that our climate is changing rapidly and we are running out of time to address it.
“I hope governments around the world who are failing to take action hear the voices of millions of people, young and old, unified in their call for action to save our planet. Our future depends on it.”
Worldwide, there are more than 4,600 events in 139 countries taking place as part of the Fridays for Future movement, and campaign group 350.org says more than 70 unions, 500 organisations and 1,000 companies have come out in support of the strikes.