It may be muddy on College Green ... But six-year-old Jasmine from North Somerset says she has saved the world.
We're told that Greta has now left Bristol by train.
That's in from our live page for today. You can find a full summary of what happened on our main story here.
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Bethan Evans
News editor, BBC West
Image source, PA MediaBYS4C insists adequate safety measures are in place for the strike
Crowds have gathered on College Green in Bristol
Campaigners want to show their support in the city
'Life in plastic isn't fantastic' says protesters
Image source, PA MediaGreta Thunberg will be joining these protesters at the Bristol Youth Strike 4 Climate (BYS4C) event on College Green
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Sharon Alcock
BBC News
People of all ages have enjoyed the big event today.
Bristol mum Jerry and four-month-old Leon joined the climate strike action in the city.
She said: “What an absolutely wonderful experience everyone really respectful, no pushing, loads of lovely teens all passionate about climate”
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Thousands of people took to the street of Bristol to protest with Greta Thunberg.
Greta told the crowds at College Green, before they took to the march: "We should not be the ones who will have to lead on this and tell the uncomfortable truth.
"Once again they sweep their mess under the rug for us young people, for their children to clean up for them."
Image source, PA Media
Image source, PA MediaThe climate strike march has now finished
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Image source, PA MediaReporter Steve Mellen was among the crowds during Greta's speech
The rain came, but not enough to keep the thousands away.
They began gathering just after first light and by the time Greta took to the stage it was hard to see the floor on College Green. And it wasn't just the green, people were clinging to any vantage point they could find.
The roar when the teenage activist stepped in front of the microphone echoed across the city centre, and her speech was regularly punctuates with roars of approval, especially when she mentioned the decision not to grant Bristol Airport planning permission to expand.
There were plenty of parents there and adults who had come to hear Greta speak but the vast majority of the crowd were young.
That's appropriate when you think this movement began when a young girl took a personal decision to stop attending school in protest at what she saw as inaction on the part of global leaders.
Clutching home-made signs and chanting slogans, they then took over Bristol city centre, creating an incredible sight through the heart of the shopping quarter.
It's a day Bristol will not forget easily, despite the rain.
Bethan Evans
News editor, BBC West
College Green has been left looking a little like a quagmire following the speeches earlier.
As such, Sustrans' head of partnerships Jon Usher is supporting action to get the area looking back to its best again.
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A Bristol City Council spokesperson said: “We will make an assessment over the next few days and decide what plan of action is required to repair and grow new grass.
"We did assess in advance whether we should put down protective matting, however a risk assessment indicated it wouldn’t prevent damage and could also be a trip hazard.”
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Jennifer Meierhans
BBC News Online
The decision of parents and teachers to allow children to skip school to attend the march has attracted some criticism on social media.
William Brown from the National Union of Teachers said many children had their schools' backing to be there.
"This is a chance for them not only to be educated on the issues which are going to shape the world they grow up in, it's also to help them feel empowered," he said.
"The feeling of powerlessness can lead to mental health problems, anxiety, all sorts if issues and we want children to feel like they will be heard, they will be taken seriously and they can make a difference."
Image source, Bristol CathedralBristol Cathedral
Bristol Cathedral says it stands with Greta Thunberg and the young climate activists, as thousands of people have joined the climate strike action.
The cathedral says it will be open as a refuge for anyone who wants a quiet space away from the crowds.
"The Diocese of Bristol has already declared a climate emergency and the Church of England has already committed all its churches to be carbon neutral by 2030.
"We stand with you."
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Avon and Somerset police have estimated around 20,000 people have come to Bristol today.
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Jennifer Meierhans
BBC News Online
Greta said: "We should not be the ones who will have to lead on this and tell the uncomfortable truth. Once again they sweep their mess under the rug for us young people, for their children to clean up for them.
"But we must continue and we have to be patient and remember that the changes required will not happen overnight since the politics and the solutions needed are still far from sight.
"But if enough people are pushing for change then change will come and we are those people and every single person counts."
Image source, Reuters"If you look throughout history, all the great changes have come from the people.
"We are being betrayed by those in power and they are failing us but we will not back down.
"And if you feel threatened by that then I have some very bad news for you. We will not be silenced because we are the change and change is coming whether you like it or not. Thank you and let's march."
Jennifer Meierhans
BBC News Online
Image source, PAGreta told crowds: "Basically, nothing is being done to halt this crisis, despite all the beautiful words and promises from our elected officials.
"So what did we do during this crucial time? What will we do, right now? Well I will not aside and watch I will not be silenced while the world is on fire, will you?"
The Swedish activist has just given a speech at College Green.
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