WATCH: Thousands take to streets across Northern Ireland for Climate Change

By Gráinne Connolly and PA reporter

Thousands have gathered in Derry/Londonderry and Belfast today to protest against Climate Change. 

The campaign was part of the wider international day of action which saw hundreds of pupils walk out of school to demand action on tackling the climate emergency. 

In Belfast, thousands marched through the city centre ahead of a rally on the grounds of City Hall.

🎥 Belfast is buzzing as young people lead the city’s #ClimateStrikes as it makes it’s way to City Hall. pic.twitter.com/uR1biKHsmB

— Q Radio News (@qnewsdesk) September 20, 2019

Organisers put the turn-out at between 3,000 and 4,000 - far in excess of the 300 they had been anticipating.

Students were given rousing cheers as they made impassioned speeches from a temporary stage outside City Hall.

🎥 Chants from students @ys4cbelfast at City Hall in Belfast calling for action to be taken on climate change. #ClimateAction #ClimateStrike pic.twitter.com/xYoH4AHgfs

— Q Radio News (@qnewsdesk) September 20, 2019

There were boos, too, when striker Ellie Crawford told the crowds that the DUP and Ulster Unionists had not replied to invites to address the gathering.

She referenced a media statement from former DUP education minister Peter Weir, who had said it was "irresponsible" to call on children to be taken out of school for the event.

The activist was met with loud cheers when she responded: "It's a bit strange when our attendance is being questioned, when Stormont hasn't been running in two years."

🎥 Climate change protestors booed the DUP and UUP for being the only NI political parties not to reply to invites to address Belfast’s #ClimateStrike. They also slated MLA Peter Weir for saying it was “irresponsible” to call on children to be taken out of school for the event. pic.twitter.com/qGOMdUJmxK

— Q Radio News (@qnewsdesk) September 20, 2019

Meanwhile, the Lord Mayor of Belfast addressed the rally and pledged to support the young campaigners.

🎥 Lord Mayor of Belfast @johnfinucane says climate change is a human rights issue not an environmental one. He also praised the students who organised the city’s #ClimateStrike and vows to stand with them. pic.twitter.com/W0bZ42rLYz

— Q Radio News (@qnewsdesk) September 20, 2019

In Derry/Londonderry, large crowds gathered outside the Guildhall for the climate strike including students who left school and their families. 

SDLP leader Colum Eastwood, Sinn Féin's Elisha McCallion and Alliance leader Naomi Long. 

People and a lot of school children arriving today to take part in the #ClimateStrike protest at the Guildhall. They join in unison with millions of others across the globe today. pic.twitter.com/VOmAdDXWtb

— Q Radio News (@qnewsdesk) September 20, 2019

These students were speaking to Q Radio from both the Guildhall in Derry/Londonderry and Belfast's City Hall. 

Each of them were proud of the turn out in two cities and are now demanding change from people across Northern Ireland including political parties. 

Rallies have also taken place in UK cities including London, Manchester and Glasgow and in other parts around the world.