Greta Thunberg during her Friday, 30 November 2018 climate change protest. Greta, 15, began a solo climate protest by striking from school in Sweden in August 2018. But more than 20,000 students around the world have now joined her. The school strikes have spread to at least 270 towns and cities in countries across the world, including Australia, the United Kingdom, Belgium, the US, and Japan. Photo: Hanna Franzen / EPA