On how coal was formed
In my previous blog we talked about Global warming, rising CO2 levels and stellar nucleosynthesis. Now, let us see how coal came into existence and the possible repercussions of a less-than efficient usage of this precious and diminishing energy source. During the early history of Earth, it is believed that the atmosphere had a higher concentration of greenhouse gases such as Carbon dioxide and methane. Free oxygen did not yet exist in the atmosphere. Then Cyanobacteria, a phylum of bacteria which began producing oxygen by photosynthesis, appeared. Cyanobacteria converted the early reducing atmosphere into an oxidizing one.
Evidence suggests that a major environmental change occurred around 2.3 billion years ago. This was the Great Oxygenation Event, also called the Oxygen Catastrophe or Oxygen Crisis. The GOE was the point when excess free oxygen started accumulating in the atmosphere. Free oxygen is toxic to anaerobic organisms, and the rising concentrations could have been responsible for wiping out most of the Earth’s anaerobic inhabitants at that time. Eventually however, aerobic organisms began to evolve, consuming oxygen and bringing about equilibrium and creating free oxygen, an important constituent of the atmosphere. Free oxygen helped in oxidizing atmospheric methane to carbon dioxide and water, resulting in the mixture of gases in the atmosphere today.
Complex life started appearing around the start of the Cambrian period, 541 million years ago, when complex multi-cellular organisms became more common, leading to the Cambrian explosion. While diverse life forms prospered in the oceans, the land however remained comparatively barren.
Terrestrial life was believed to have been well established by around 359 million years ago, corresponding with […]