As the home of human beings, the earth is constantly changing, in which human activities and natural factors are affecting the shape of the earth. In the past few decades, the "weight" of the earth has also gradually increased.

On the one hand, most of the earth's surface has been transformed by human beings, such as agriculture, mining and urbanization. , make the surface material into the atmosphere, increasing the quality of the earth. On the other hand, the earth also increases its mass by absorbing gases such as carbon dioxide in the atmosphere. According to scientists' estimation, the mass of the earth is increasing by about 3 million tons every year.

The earth is the third planet from the sun and the only celestial body known to human beings that breeds and supports life. About 29.2% of the earth's surface is land composed of continents and islands, and the remaining 70.8% is covered by water, mostly salty water bodies such as oceans and bays, but also fresh water bodies such as lakes, glaciers and rivers, especially glaciers, forming hydrosphere.

The World Earth Day

Earth Day, that is, April 22nd every year, is a festival specially set up for world environmental protection, aiming at raising people's awareness of existing environmental problems, mobilizing people to participate in environmental protection movements, and improving the overall environment of the earth through a green and low-carbon life. Earth Day was initiated by Gaylord Nelson and dennis hayes in 1970.

Today, the celebration of Earth Day has developed to 192 countries around the world, and more than 10 billion people participate in it every year, making it the largest folk environmental protection festival in the world. China Biodiversity Conservation and Green Development Foundation (hereinafter referred to as China Green Development Association) is a cooperative organization of "Earth Day".