People participate in a march calling for action against climate change in Brussels, Belgium, Sept. 20, 2019. (Photo by Riccardo Pareggiani/Xinhua)

BRUSSELS, Sept. 21, 2019 (Xinhua) -- People participate in rallies calling for actions against climate change in several European cities.

People participate in a march calling for action against climate change in Brussels, Belgium, Sept. 20, 2019. (Photo by Riccardo Pareggiani/Xinhua)

A girl holds a placard during a march calling for action against climate change in Brussels, Belgium, Sept. 20, 2019. (Photo by Riccardo Pareggiani/Xinhua)

People participate in a march calling for action against climate change in Brussels, Belgium, Sept. 20, 2019. (Photo by Riccardo Pareggiani/Xinhua)

Young people participate in a march calling for action against climate change in Brussels, Belgium, Sept. 20, 2019. (Photo by Riccardo Pareggiani/Xinhua)

A man holds a placard during a march calling for action against climate change in Brussels, Belgium, Sept. 20, 2019. (Xinhua/Zheng Huansong)

A girl holds a placard during a march calling for action against climate change in Brussels, Belgium, Sept. 20, 2019. (Xinhua/Zheng Huansong)

A Greek student holds a banner during a school strike for climate change in Athens, Greece, on Sept. 20, 2019. The School Strike for Climate on Fridays for Future (FFF) is an international movement of students who take time off from class to participate in demonstrations, in order to prevent further global warming and climate change. In Greece, high school students in 14 cities all over the country decided to skip classes, joining the initiative. (Xinhua/Marios Lolos)

Greek students take part in a school strike for climate change in Athens, Greece, on Sept. 20, 2019.(Xinhua/Marios Lolos)

Greek students take part in a school strike for climate change in Athens, Greece, on Sept. 20, 2019.(Xinhua/Marios Lolos)

Greek students take part in a school strike for climate change in Athens, Greece, on Sept. 20, 2019.(Xinhua/Marios Lolos)

Greek students take part in a school strike for climate change in Athens, Greece, on Sept. 20, 2019.(Xinhua/Marios Lolos)

Protesters take part in the Global Climate Strike protest in central London, Britain, on Sept. 20, 2019. (Photo by Ray Tang/Xinhua)

Protesters take part in the Global Climate Strike protest in central London, Britain, on Sept. 20, 2019. (Photo by Ray Tang/Xinhua)

Protesters take part in the Global Climate Strike protest in central London, Britain, on Sept. 20, 2019. (Photo by Ray Tang/Xinhua)

A high school student holds a placard during a rally against global warming in front of the government building in Skopje, North Macedonia, Sept. 20, 2019. (Photo by Darko Duridanski/Xinhua)

High school students hold placards during a rally against global warming in front of the government building in Skopje, North Macedonia, Sept. 20, 2019. (Photo by Darko Duridanski/Xinhua)■