Changing world

The world is changing. In fact, everything is changing, the universe, our galaxy, the solar system, earth and earths climate. Earth is 4.56 billion years old and in that time the short-waved ultra violet radiation created by the our central fusion rector intensified. Earths atmosphere was probably made of helium and hydrogen in the beginning, before it was lost into the universe. Then the atmosphere was made mainly of carbon dioxide and nitrogen without oxygen. Only 2.7 billion years before today oxygen was enriched in the atmosphere, allowing the synthesis of ozone and the creation of the protecting layer that is one of the keys to the emergence of life. Nevertheless, the great oxidation led to a major glaciation of the whole planet – the huron ice age or snowball earth. Continental drift and huge volcanic eruptions probably caused the end of the frost. Several asteroid impacts, at least two super continents and another snowball earth later and life began to flourish. Oxygen became a major constituent of the atmosphere and the levels of carbon dioxide dropped. The values still fluctuated, leading frequently to climate change and big challenges to all organisms. The dependencies and connections between all key elements of system earth lead to a more or less rapid change of its climate. The physical and chemical basics are described in this chapter.