Roads have been brought to a standstill as thousands of schoolchildren protested against climate change.

As protesters in London took part in the UK-wide Youth Strike 4 Climate action, some took to the city’s famous buses to demonstrate.

One group, who looked to be in their late teens, took over an open-top tourist bus, climbing to the top deck and conducting their protest from there.

Others sat on the roads around Parliament and chanted “we’re not moving” as they created a human blockade.

Elsewhere, a duo clutching a bottle of champagne made their way on to the top of a number 11 double decker bus to Fulham Broadway.

The action has been taking place across the country with youngsters – some wearing their school uniform – carrying banners bearing slogans such as: “There is no planet B”.

Climate change protest
Students from the Youth Strike 4 Climate on an open-top tourist bus (Verity Bowman/PA)

Other signs read: “When did the children become the adults?” and “Why should I clean my room when the world is in such a mess”.

In Belfast, a small but passionate crowd of young people gathered outside City Hall.

Maia Willis Reddick, a 17-year-old student at Belfast’s Methodist College, said her school had been supportive of her joining the action.

She said: “Us leaving school means we show we value the climate the same as we value our education,” she said.

“We are still very conscious about school. I have A-levels, I have stuff to do, we just want to make the point that we are willing to take drastic action in order to highlight the problems of climate change.”

Pupils from Methodist College Belfast at a climate change protest outside Belfast City Hall
Pupils from Methodist College Belfast at a climate change protest outside Belfast City Hall (Brian Lawless/PA)

Nico, 13, was protesting at Parliament Square in Westminster.

She said protesting about climate change was not a “chance to bunk off school”, but “a push for a better future”.

Ten-year-old Zachary Hird, a pupil at Cambridge’s Newnham Croft Primary School, was at the protest in Cambridge with his mother Diane Hird.

He said: “We don’t want climate change and people just have to change their ways as we don’t want the world as it is right now.

“We just want to make people aware of it.

“We were talking about it in our class so we just came along.”

Children also gathered in Brighton, with some waving banners refusing to take exams and calling for immediate action on climate change.

They cheered as they were joined by Brighton Pavilion MP Caroline Lucas.

She told them they should only miss school in exceptional circumstances, adding: “The evidence is really shocking, we have less than 12 years to get off the collision course that we’re on, my generation has let you down.

“In the last 12 months there’s only been one debate on climate change in Parliament.

“There is a better way forward.”

A student from the Youth Strike 4 Climate movement climbs on to an Underground sign during a climate change protest at Parliament Square, Westminster
A student from the Youth Strike 4 Climate movement climbs on to an Underground sign during a climate change protest (Verity Bowman/PA)

However, the strikes were not welcomed by school leaders and Education Secretary Damian Hinds, who said missing class was not the answer.

Geoff Barton, general secretary of the Association of School and College Leaders, said: “While we admire the determination of these young people to make their voices heard over climate change, missing school is not the right approach.

“The problem is not only the disruption and loss of learning time but the fact that schools have responsibility for the safety and wellbeing of pupils, and it is a serious concern if pupils are off site and unsupervised.

“We appeal to all involved in the protests not to repeat the exercise, particularly as many students will soon be taking exams which are crucial to their life chances.”

Climate change protest
Three-year-old Violet Wicks, from London, joined the protest in Westminster (Nick Ansell/PA)

Downing Street said that while it was important for young people to engage with issues such as climate change, the disruption to planned lesson time was damaging for pupils.

“Everybody wants young people to be engaged in the issues that affect them most so that we can build a brighter future for all of us,” a No 10 spokeswoman said.

“But it is important to emphasise that disruption increases teachers’ workloads and wastes lesson time that teachers have carefully prepared for.

“That time is crucial for young people, precisely so that they can develop into the top scientists, engineers and advocates we need to help tackle this problem.”

Climate change protest
Students protest in Westminster (Nick Ansell/PA).

But the demonstrators gained the support of Scotland’s First Minister Nicola Sturgeon, who described their actions as a “cause for optimism in an often dark world”.

The movement has already seen school strikes in Australia and European countries including Belgium, and was inspired by teenager Greta Thunberg, who protests every Friday outside Sweden’s parliament to urge leaders to tackle climate change.

It comes in the wake of a UN report which warned that limiting global temperature rises to 1.5C above pre-industrial levels, beyond which climate impacts become increasingly severe, requires unprecedented action.

That includes cutting global carbon dioxide emissions by almost half within 12 years.

Climate change protest
Scenes outside Downing Street (Stefan Rousseau/PA)

Students in the UK are demanding the Government declare a climate emergency and take active steps to tackle the problem, communicate the severity of the ecological crisis to the public and reform the curriculum to make it an educational priority.

Anna Taylor, of UK Student Climate Network, said: “We’re running out of time for meaningful change, and that’s why we’re seeing young people around the world rising up to hold their governments to account on their dismal climate records.

“Unless we take positive action, the future’s looking bleak for those of us that have grown up in an era defined by climate change.”