Thousands of people have gathered in Belfast and Londonderry to protest against climate change.
Many schoolchildren were present as a demonstration began in Belfast’s Cornmarket.
Some protesters held a short “die-in” to highlight the threat they say climate change poses to humanity.
A rally was scheduled to be held at the City Hall at which there was expected to be calls for more action to combat global warming.
A protest has also taken place in Derry’s Guildhall Square, where hundreds of school pupils joined families and workers in the call for immediate action on climate change.
Emma Farren, one of the organisers of the Derry protest, said momentum was building locally and globally.
“Our last strike in July got about 15 people – now we are standing here and there are hundreds of people.
“There is nowhere to hide from it now,” she said.
SDLP leader Colum Eastwood, Sinn Féin MP Elisha McCallion and Alliance Party leader Naomi Long were among the politicians taking part in the Derry protest.
The Northern Ireland protests are part of a series taking place across the UK, with pupils leaving schools and workers downing tools as part of a global “climate strike” day.
Rallies are taking place in cities including London, Manchester and Glasgow, urging “climate justice” and an “end to the age of fossil fuels”.
Students and workers have also been encouraged to set off alarm clocks across the UK at 13:00 BST.
Energy Minister Kwasi Kwarteng said their voices were being heard.
However, he said he could not endorse children leaving school to take part.