Our planet Earth was born 4.6 billion years ago . But then , he had the look of today : rocks , water and air were formed slowly and then appeared life.
After 4.6 billion a huge cloud of gas and dust material that revolves condensed space and gave birth to a star , the sun . Near the Sun, rock powders were crowded and they moulder 9 planets of the solar system , including Earth .
Since its formation , the Earth has evolved a lot . Its history has been marked by important events that form the oceans, the emergence of life , the appearance or disappearance of animals and plants. Scientists have called the first time in the history of the Precambrian Earth ( now - 4600 to 540 million years).
Then follows four periods called geological eras : Era Primary ( 540-245 million years ago ) , was secondary ( 245-64 million years ago) , the tertiary ( 65-2 million years ago ) , and, finally , was the Quaternary ( 2 million years ago - until today ) .
From that time until today , the Earth experienced a series of major changes in terms of appearance environment.
The environment or environment means all elements and natural and artificial phenomena from outside the Earth , which makes the life in general and that of man in particular. The meaning of this notion within the European Union is one of a number of factors which , in the complexity of their relations , the framework , middle and human living conditions , which are often the ones that are not felt . Another definition is found in the Environmental Protection Law , the environment is the set of conditions and natural elements of Earth: air , water, soil and subsoil , all layers of the atmosphere, all organic and inorganic matter and living beings , natural systems interaction , copper
