Scores of schoolchildren around the world have walked out of their classrooms and trooped on to the streets for a second time to demand that politicians take action on climate change.
British students join striking counterparts in 120 other countries including New Zealand, Australia and Japan with an expected 2,000 rallies worldwide.
Hundreds of these placard-waving youngsters ditched their lessons and flocked to London's Parliament Square this morning to try to grab the attention of MPs.
They chanted 'this is what democracy looks like' while primary school children, who were at the protest with their parents and holding handmade placards, shouted 'climate change, boo!'
But one group of teenagers went further, and shouted: 'One two three four, Theresa May's a f***ing whore, five six seven eight, Corbyn is f***ing great!'
The walkouts are taking place in more than 100 UK towns and cities, including Kent, Edinburgh and Bristol, as part of a global day of action inspired by teenager Greta Thunberg who protests every Friday outside Sweden's parliament.
Hundreds of placard-waving youngsters ditched their lessons and flocked to London's Parliament Square this morning to try to grab the attention of MPs. Placards read 'denial is not a policy' and 'system change not climate change'
The students walked out of their classrooms and took to the streets across the world. Some 2,000 rallies are expected to happen globally including 100 events in UK towns and cities (Parliament Square pictured)
The demonstration outside the Houses of Parliament soon marched the short walk to the Mall where they descended outside the gates of Buckingham Palace. One protester climbed up the Queen Victoria Memorial outside the iconic building
Greta Thunberg is a 16-year-old pig-tailed Swedish schoolgirl who has been obsessively researching climate change for seven years.
Since last summer, she has been skipping school every Friday to sit on the steps of the Swedish parliament, the Riksdag, with a home-made sign that reads 'Skolstrejk för Klimatet' (School strike for the climate).
She grows her own vegetables, refuses air travel and luxury hotels, even if the only option is a 32-hour train journey and a tent.
She accused the attendees at the United Nations Climate Change Conference in Poland in December 2018 of leaving the burden of climate change with future generations.
Many politicians, including environment secretary Michael Gove and Labour leader Jeremy Corbyn have already backed the 'inspirational strikers'.
Greta Breveglieri, 21, a political science student at Univesita Statale Di Milano, travelled from Italy for the London demonstration today.
She said: 'The protest in February was really big, but today is way more important and has been way more publicised. There's been a lot of momentum, so I think it's going to be big.
'To put it bluntly, we're here because our world is going to be destroyed. We have to change the pace of our culture, our society, our politics, our economics.
'We have been silent for too long. There have been singular voices or movements that have always struggled against climate change, and for the environment and against pollution.
'But this kind of global and coordinated and spontaneous, and especially youth movement, I've never seen this movement before.'
Thousands of students defied warnings from teachers and politicians when they bunked off on February 15 and the organisers predict that even more will skip classes to protest today.
While the youngsters may not have the support of Downing Street and education secretary Damian Hinds, who disapproves of the children missing school, an Opinium poll suggested that a majority of the public backs the walkout.
This is the second time students have defied warnings from teachers and politicians to skip class and take to the streets to protest about the climate change cause (Parliament Square pictured)
A large crowd gathered on Bristol's College Green as part of the worldwide walkout. Students in Japan, Australia and New Zealand are also expected to take part
The students' calls come after a UN report last year which warned that limiting global temperature rises to 1.5C above pre-industrial