Tens of thousands of protesters, many of them school students, gathered in towns and cities across the Asia-Pacific on Friday, at the start of a worldwide day of protest ahead of a United Nations climate summit next week.From the Pacific Islands, many of which risk being inundated by rising seas, to New Zealand, Australia and Thailand, people took to the streets to call on governments to take urgent steps to tackle the climate crisis and prevent an environmental catastrophe.Greta Thunberg, the 16-year-old Swede who inspired the climate strike, tweeted her support."Incredible pictures," she wrote from New York where she will lead the protest. "This is the huge crowd building up in Sydney. Australia is setting the standard!"Protests were expected to take place in 110 towns and cities across Australia, the world’s largest exporter of coal and liquid natural gas, with crowds calling on the government to commit to a target of net zero carbon emissions by 2030. At least 2 000 companies gave people time off in order to attend the rally, the Sydney Morning Herald reported."We are not sinking, we are fighting," read one of the placards carried by protesters in Kiribati, a chain of atolls in the the Pacific ocean that some fear could be under water within 25 years. In Bangkok, which at just 1.5m above sea level also risks being inundated, protesters marched to the Ministry of Environment to deliver a letter calling on the government to declare a climate emergency."There is no Planet B," said one of the signs, beneath a sketch of a human being holding up the earth.Day of protestProtests are planned in some 150 countries on Friday, and will culminate in New York when Thunberg, who has been nominated for a Nobel prize for her activism on climate, leads the march in the city where the UN has its headquarters.The UN summit brings together world leaders to discuss climate change mitigation strategies, including the move from fossil fuels to renewable energy sources.In some countries, including Australia and the United States, climate change policy has become a political football.US President Donald Trump said in 2017 that he would pull the US out of the Paris Agreement under which countries have committed to cutting greenhouse gas emissions to tackle rising global temperatures.Australian Finance Minister Mathias Cormann told parliament on Thursday that students should not take part in the protest movement. "When school is sitting, students should go to school," he said.Alison, a 12-year-old primary school student, told an estimated that 10 000 people who had gathered in the Australian capital of Canberra, said she and her classmates had decided that saving the planet was more important."Politicians worry about us not going to school," she said. "But we're learning about the world, the danger we're in and what we can do about it. We know it's important to go to school and learn, but we know it is more important to save the planet for future generations to learn on." Danielle Porepilliasana, a high school student in Sydney's inner west, said politicians needed to wake up."World leaders from everywhere are telling us that students need to be at school doing work," Porepilliasana told Reuters."I'd like to see them at their parliaments doing their jobs for once."