Crowds of children skipped school Friday to join a global strike against climate change, heeding the rallying cry of teen activist Greta Thunberg and demanding adults act to stop environmental disaster.
It was expected to be the biggest protest ever against the threat posed to the planet by climate change.
Yelling slogans and waving placards, children and adults across Asia and the Pacific kicked off the protest, which spread later to Africa and Europe with crowds filling the streets in Paris, London and Berlin.
"We are the future," said Vihaan Agarwal, 15, protesting in Delhi.
"We believe there is no point in going to school if we are not going to have a future to live in."
Organisers forecast one million participants overall. In Australia alone, they said more than 300,000 children, parents and supporters rallied.
"I'd like to ask you not to cut down forests, and reduce garbage production, and not to use so many petrol-fuelled cars," five-year-old Teo, told a crowd of 500 in Slovakia.
"Stop climate change now" and "There is no planet B" read some of the signs brandished by demonstrators in a trendy central shopping district of Tokyo.
"We adults caused this planet emergency," said one of them, Chika Maruta, 32, marching with her colleagues from a cosmetics company.
"We should take our responsibilities for the next generation."
'We deserve better'
Swedish schoolgirl Thunberg, 16, has accused leaders of not doing enough to prevent harmful climate change by curbing gas emissions.
On the eve of the strikes, she insisted solutions were being "ignored".
"Everything counts, what you do counts," she said in a video message to supporters.
Demonstrators young and old echoed her cry.
About 200 marched in Ghana's capital Accra, where some 44 percent of the country's population has not heard of climate change, according to a study by Afrobarometer.
"Developing countries like Ghana are the most affected. We don't have the resources to adapt to climate change," said 26-year-old protest organiser Ellen Lindsey Awuku.
Hundreds of others also took to the streets in Kenya and Uganda.
The demonstrations were due to culminate in New York, where 1.1 million students in around 1,800 public schools have been permitted to skip school.
Events began in the deluge-threatened Pacific Islands of Vanuatu, the Solomons and Kiribati, where children chanted: "We are not sinking, we are fighting."
The defiance message was heard across Asia.
"We are the future and we deserve better," 12-year-old Lilly Satidtanasarn -- known as "Thailand's Greta" for her campaigning against plastic bags in malls -- told AFP in Bangkok.
"This (problem) was created by the generation before us... so much is at risk because of one generation and it is up to the next generation to change all of that," said 16-year-old Reezan Ahmed at a protest in Pakistan's capital Islamabad, where some 1,000 people demonstrated.
'You're being lied to'
In Australia, some local authorities, schools and business encouraged people to take part in the strikes.
Australia has been struck in recent years by droughts, more intense bushfires, devastating floods and the blanching of the Great Barrier Reef -- phenomena blamed on a changing climate.
Numerous peer-reviewed scientific studies have shown a link between human-made gas emissions and climate change.
But the protests also laid bare resistance from those who question the threat.
Australian ruling coalition parliamentarian Craig Kelly on Thursday told children that "everything you're told is a lie".
"The facts are, there is no link between climate change and drought, polar bears are increasing in number."
Businesses taking action
An increasing number of businesses backed the protests.
Amazon chief Jeff Bezos on Thursday pledged to make the US technology and retail giant carbon neutral by 2040 and encourage other firms to do likewise.
Friday's mass action set the scene for a range of high-profile climate events in New York.
A Youth Climate Summit will take place at the United Nations on Saturday.
UN Secretary-General Antonio Guterres will then host an emergency summit on Monday in which he will urge world leaders to raise their commitments made in the 2015 Paris climate accord.
The agreement saw countries pledge to limit the long-term rise in the average temperature of the Earth to two degrees Celsius (3.6 degrees Fahrenheit) over pre-industrial levels, and if possible, to 1.5 degrees Celsius.
A landmark UN report to be unveiled next week will warn that global warming and pollution are ravaging Earth's oceans and icy regions in ways that could unleash misery on a global scale.
The scientific report from the Intergovernmental Panel on Climate Change (IPCC) will be put to a gathering of experts from 195 countries meeting in Morocco from Friday.