Until about 2 billion years ago the Earth’s atmosphere was rich in carbon dioxide (CO2). Then, as the Earth cooled, the CO2 began to combine with nutrients in the oceans to produce organic material. Oxygen was released. Dead material sank to the ocean floor and, over the passage of millions of years, was trapped, heated, pressed and converted to the oil and gas we use today. Land based vegetation later was converted to coal. When we burn these ’fossil’ fuels we are reversing millions of years of geological process.
Authors: David Nowell, Richard Balmer