Crowds of children skipped school on 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.

Ghana’s capital Accra, where some 44 per cent of the country’s population has not heard of climate change, according to a study by Afrobarometer.

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.

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.

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.