As the only known planet that is habitable for human beings, the Earth’s importance is self-evident. Every living organism known to science obtains all of its resources from Earth, and has very few other options available. Without the Earth, humans would be doomed to extinction, unless they were able to adapt to another planet's conditions before the Earth disappeared.
All living organisms require a proper habitat, or a surrounding region that supplies all of its resources, such as food, water and oxygen. The Earth has many different habitats, including deserts, forests, grasslands, lakes, rivers and swamps. Additionally, the oceans of the world form a single large habitat, called the marine biome.
Some creatures alter or create their own habitats to suit their needs. Ants, termites, woodpeckers and other animals modify trees and other items in their habitat to meet their needs. Beavers take trees and build large and elaborate dams to live in the water. Humans go even further, and have created several unique habitats, such as urban, residential and agricultural areas.
Humans have created small areas of habitat that can leave the planet Earth, which go by the names of space shuttles, rockets and space stations. However, these habitats require resources from the Earth to function. Additionally, these habitats can only support a few individuals or animals for a relatively short period of time.