More than one million students around the globe skipped school last Friday and took to the streets, dramatically ramping up their protest against inaction on climate change by governments and big corporates.
In more than 2,000 cities and towns across dozens of countries, the message was clear: climate change is a crisis and needs to be treated as such.
That sort of tough talking has made some adults uncomfortable. But youth activists say the strikes will continue if their demands for much tougher climate action are not heeded.
Seventeen-year-old Kate Anchondo said at a strike in San Diego: "We will never run out of ways to demand the right to a healthy environment. We will continue to disrupt the social order if we have to."
Young people, she said, are sometimes considered by the adults to be small and insignificant.
"But together, as students striking all over the world, we are the biggest and most powerful voice," added the high school student, who had organised the strike in line with the first global youth climate movement.
WHOLE NEW WAY OF THINKING NEEDED
The bigger your platform, the bigger your responsibility. The bigger your carbon footprint, the bigger your moral duty... But you must also realise that the changes required are beyond today's economic system. We need a whole new way of thinking.
SWEDISH TEENAGER GRETA THUNBERG, 16, who inspired the event.
The event was inspired by Swedish teenager Greta Thunberg, 16, who went on the first solo climate strike last August. She had refused to go to school in a bid to pressure her government into taking more drastic climate action. Since then, many other young people have been inspired to do the same.
Last Friday's event, however, was the first global one. Estimates by international climate organisation 350.org said more than one million young people took part.
'DON'T BURN MY FUTURE'
Students marched through cities and neighbourhoods broadcasting their message. In San Diego, they held up hand-drawn placards with messages such as "respect existence, or expect resistance" and "don't burn my future".
"If we let climate change go on, we won't have a future. And so I'm asking, please fix this, before my future is destroyed," said Luna Uribe, 10, who was at the San Diego strike.
In Hong Kong, chants of "we want change" and "seas are rising, so are we" drifted through the air, drawing the attention of curious onlookers as 800 to 1,000 people marched from Chater Garden in Central to the government's headquarters in Admiralty.
The march was led by classmates Zara Campion, Elisa Hirn and Emily Tarr, who wanted to raise environmental awareness among Hong Kong's youth.
Swedish-born Elisa, 17, said the group has written a statement to the government. "One of our biggest requests is to have a youth delegate in the government so that the younger people can work more closely with the government, and hopefully through that we can push for other bigger ideas that we have in mind."
The trio also called on the government to at least double its renewable energy target. The government's climate action plan is to raise it to 3-4 per cent by 2030, from the existing 1 per cent.
But Adele Lo, 16, said more could be done. "Guangzhou (on the mainland) uses more than 30 per cent renewable energy while we only use 1 per cent and that's a huge gap because it's so close to us and yet we're so different and we're lagging so much behind."
BIG, BOLD POLICIES
In Sydney, about 20,000 students marched through the city centre, demanding politicians "listen to the science". The protests came ahead of state and federal elections.
Thea Archibald, 16, who was protesting with a group of school friends, said she wanted "a better future for my children". "I would just like the government to be more aware and stop denying problems that have been proved by science," she told The Sunday Times.
The students directed much of their anger at Australia's Prime Minister Scott Morrison, who has resisted action to curb carbon emissions and has voiced support for the coal industry.
His calls for students to stay in school had little effect. About 150,000 students protested around the country. A student leader who addressed the Sydney protest, Ms Crystal Russell, said Australia risked dire consequences if politicians did not immediately act to address climate change.
"They are not listening to the symptoms - the droughts, the bush fires, the storms, the rising oceans," she said.
Many pointed to the importance of individual choices, such as walking more and taking public transport. These actions can reduce pressure on the environment.
But the urgency of the problem required implementation of bold policies and actions. "For that to happen, it takes all of us to come out and push our elected officials to do so," said Kate during the climate strike in San Diego.
Scientists say burning fossil fuels such as coal is a major source of greenhouse gases that trap heat and raise global temperatures, bringing more floods, droughts, heatwaves and rising sea levels.
NEW WAY OF THINKING
Chula Vista mayor Mary Salas, who attended the strike in San Diego, told The Sunday Times she was encouraged by Kate's initiative to address "the biggest problem facing their future".
"I thought that as mayor of the city of Chula Vista, I should do all I could to make them feel welcome. So I invited them to this space here at City Hall," she added.
In an e-mail interview with The Sunday Times, Swedish teen Greta said that everyone has a role to play in making the "enormous changes" required to limit global warming.
Going vegan, buying only what is needed and avoiding taking airplanes, is a good start on a personal level. But larger-scale changes are required.
Greta, who has been nominated for the Nobel Peace Prize, added: "The bigger your platform, the bigger your responsibility. The bigger your carbon footprint, the bigger your moral duty.
"But you must also realise that the changes required are beyond today's economic system. We need a whole new way of thinking."