Children learn about the Earth at Changxing Jindingzi Geological Museum in Huzhou, East China's Zhejiang province, on April 21, 2021. [Photo by Wu Zheng/Asianewsphoto]

Every year on April 22, Earth Day marks the anniversary of the birth of the modern environmental movement in 1970. It highlights environmental issues, including the loss of biodiversity and increasing pollution. The theme for this year's observance is "Restore Our Earth".

Students paint a "green Earth" on a soccer ball at an event for protecting the environment and the Earth at Heping Primary School in Yaohai district of Hefei, East China's Anhui province, on April 19, 2021. [Photo by Xie Chen/Asianewsphoto]

Children paint on a cloth of their imaginary home at an event for protecting the environment and the Earth at a community in Luyang district of Hefei, East China's Anhui province, on April 19, 2021. [Photo by Zhao Ming/Asianewsphoto]

A teachers teaches students knowledge of the Earth at Fuhe Primary School in Hanshan district of Handan, North China's Hebei province, on April 21, 2021. [Photo by Hao Qunying/Asianewsphoto]

Children sign their names on a banner at an event for protecting the Earth in the Luyang district of Hefei, East China's Anhui province, on April 21, 2021. [Photo by Ge Chuanhong/Asianewsphoto]

Children in clothing made of plastic bags and other materials walk at a show for protecting the environment in Changxing county, Huzhou, East China's Zhejiang province, on April 21, 2021. [Photo by Wu Zheng/Asianewsphoto]

Workers clean waste in a river in Taizhou, East China's Zhejiang province, on April 19, 2021. [Photo by Jiang Youqing/Asianewsphoto]