Lance Lau Hin-yi is 10 years old, 1.48 metres (4ft 10in) tall, and gazes at the world through owlish glasses.

When you look at him, the term “climate activist” does not immediately spring to mind. Yet since September, Lance has been conducting a solo protest at school in Hong Kong every Friday to draw attention to issues harmful to the environment.

Sidestepping two pet cats in the living room of his family’s home in Tung Chung, on Lantau Island near Hong Kong’s international airport, Lance picks up the protest placard he drew and, with a broad grin, brandishes it high above his head., His voice rising an octave, he says: “People need to get to the recycling bins now or die.”

“Too much greenhouse gas is being released into the atmosphere, from factories, aeroplanes, cars, motorcycles, basically anything that is related to burning fossil fuels. We have to call a halt [to it],” he says.

Lance’s campaign, inspired by the Swedish teen activist Greta Thunberg – who launched the #FridaysForFuture movement in 2018 by staging a school strike every Friday to protest outside the Swedish parliament – was initially met with ridicule by some of his fellow students at Ying Wa Primary School in Sham Shui Po, Kowloon, who labelled him “stupid” and “crazy”.

“Part of the problem was that while the English on my protest placard is quite clear – ‘School Strike for Climate Action’ – the Chinese reads ‘If We Don’t Have a Future, Why Should We Go To School’,” Lance explains. “But my drawing’s message is pretty clear: part of it is [a] city, part of it is burning forests … the tide is coming in and there’s the deforestation.”

Fluent in English, Cantonese and Mandarin Chinese, Lance says he has been trying to engage anyone who will listen to his message as he stands by the school gates.

“Some people were neutral, some people were quite friendly. I had to keep telling everyone not to be scared. I’m not that sort of aggressive protester. I’m just protesting about the climate, not the kind of person who goes around burning things.”

When Lance began his strike, there were concerns within the school that his activity would be disruptive. So he agreed to limit it to lunchtimes and breaks between class, and has since scaled his protest back further, to an hour before morning lessons begin on Fridays.

The reaction of Ying Wa’s teachers has ranged from cautious neutrality to outright encouragement, the latter led by the school’s principal, Sylvia Chan Mei-kuen.

“Amazingly, Mrs Chan was very supportive,” says Lance. “She’s very environmentally aware. One of the first things she did after she took up the post was to introduce online lunch order forms, so nobody had to use paper any more.”

Ying Wa’s vice-principal, Eve Lee Yee-mei, says Lance is conveying a positive message. “He’s a good student, and has always acted in a peaceful and harmonious way with respect to others, and the school supports him,” she says.

Even students who had greeted his efforts with derision changed their minds when they saw how serious Lance was about his crusade.

“As a family, we’ve been leading a green life for quite some time,” Lance says, “and then Greta came along. She really impressed on me that the environmental situation is very important. You have to do something about it. You can’t just carry on as if it is business as usual.”

This summer the family visited Europe, travelling by rail between Amsterdam, Berlin and Prague. “Trains are much better than cars or planes, or almost any other form of transport. Far easier, less carbon emission, and the stations are right in the centre of town,” Lance says. “I’ve also been to Brazil because I wanted to see the Amazon, its natural landscape and amazing wildlife.”

Lance looks across his dining room table with an expression that brooks no argument.

“Hong Kong imports a huge amount of Brazilian meat – almost 400,000 tonnes a year; but they are burning down the rainforest in the Amazon to farm cows for meat for Hong Kong and mainland China. In fact, it’s my understanding that Hong Kong eats more meat from Brazil than the whole of the rest of China,” he says.

“Whether it comes here by sea or by air, either way it causes carbon emissions, so I want to tell people to stop buying Brazilian meat and eat less beef.”

Lance’s school protest is not his only activity against climate change.

He was an enthusiastic participant in last month’s worldwide climate protests. With family and friends, he runs beach clean-ups, combing the mangroves near Tung Chung for debris while admiring the mudskippers, horseshoe crabs and other wildlife. He also takes part in meditation sessions that aim to bring a semblance of calm amid Hong Kong’s current troubles.

“We are trying to create a grid of love and peace to get away from the disruption caused by the protests, as the future looks grim now,” he says.

At home, he runs a mini production line, crowding the family flat with recycled plastic bottles containing citrus peel, water and sugar to create a natural cleaning fluid. “You just need to stir it a couple of times while the ingredients blend together, test it with PH paper after three months, and – ta-dah! – you’re done.”

The kitchen has also been pressed into service to make cupcakes, which Lance passes out to people working in the community. “If you’re a climate ambassador, you are also a love ambassador, because we are doing this out of love for the planet. So we hand out cupcakes to everyone who serves us in the community,” he says.

The reactions of street cleaners, security guards and MTR staff in Tung Chung have varied from amazement to delight.

“We were really surprised that the staff at Maxim’s cake shop lapped them up, maybe because they were home-made. The staff have been under a lot of pressure recently because of their boss’ comments on China,” he says, referring to remarks made by the daughter of Maxim’s founder opposing the anti-government protests in Hong Kong. Lance pauses before adding: “I’m not taking sides here.”

Lance’s mother, Martina, says the family has encouraged his interest in the environment, “but he comes up with a lot of his own ideas, and his incredible enthusiasm is very much his own”.

“His Chinese name means ‘all change’ and I think, given his commitment and determination, that he will make a lot of changes so that he and his generation grow up in a better world.”

Lance’s crusade has been applauded by fellow Hong Kong environmental campaigner Gavin Coates, whose bestselling children’s books, such as Pinky the Dolphin and the Power That May Be, and The Search for Earthy’s Best Friend trumpet green issues.

“He is not waiting around to see what’s going to happen. He is taking action now, teaching our older, but none-the-wiser, generation how we should be taking responsibility. When I think of how gormless I was at his age, my admiration ratchets up even further,” Coates says.

Lance, who hopes to become an architect, has no intention of ending his strike, and is planning to meet recently elected Islands district councillor Randy Yu Hon-kwan for talks.

Ticking off the points on his fingers with the fervour of someone twice his age, his voice rises an octave again.

“I want to tell Mr Yu we need more recycling stations, even for food, so it can be used as fertiliser, and we need to plant more trees and reduce carbon. And there should be more solar panels and wind farms,” he says.

“In the meantime, I intend to carry on my strikes and campaigning for the environment until the world is no longer on the brink of extinction.”