People take part in a Global Climate Strike rally in Seoul, South Korea, September 21, 2019. Thousands of South Koreans, led by activists, laid on the ground signifying their deaths in a demonstration on Saturday (September 21) to demand action on climate change ahead of next week's climate summit at the United Nations. REUTERS/Heo Ran

People stage die-in during a Global Climate Strike rally in Seoul, South Korea, September 21, 2019. Activists from environmental organizations, schools and religious groups took part and urged a government and people to take action for climate change and reducing carbon dioxide emissions. REUTERS/Heo Ran

People take part in a Global Climate Strike rally in Seoul, South Korea, September 21, 2019. Police estimated that about 3,000 people gathered in central Seoul while holding banners carrying messages such as 'save earth save us' and 'It's time to act'. REUTERS/Heo Ran

People take part in a Global Climate Strike rally in Seoul, South Korea, September 21, 2019. REUTERS/Heo Ran

People stage die-in during a Global Climate Strike rally in Seoul, South Korea, September 21, 2019. Yonhap via REUTERS

People march carrying a globe-shaped balloon as they take part in a Global Climate Strike rally in Seoul, South Korea, September 21, 2019. REUTERS/Heo Ran