125. THE FIVE PHASES OF THE FOSSIL FUEL ERA

The cross-over points where production of one fossil fuel exceeds another are an interesting structural feature of energy production. There are 5 of these points, and they delimit the five phases of the fossil fuel era.

1) The Age of Coal: First there is only coal, and its production rises alone. This phase begins in the early 1800s, and continues until around 1965, as can be seen in the following chart (click to enlarge):Source(pdf)
2) The Age of Oil: Oil rises and exceeds coal. This is the point in the above chart where the green line (oil) crosses over the black line (coal). The cross-over happened in the mid 1960s and marked the beginning of the Age of Oil.

3) Natural gas rises and exceeds coal. This is happening right now. According to the DOE's Annual Energy Review 2004 (p. 299), world coal production in 2002 was 99.69 quads, while world natural gas production was 98.7 quads. In the following graph, this second cross-over point is the point where the green line (gas) crosses over the yellow line (coal):World Energy Consumption by Fuel Type, 1970-2020Source
4) The Age of Natural Gas: Oil peaks and falls, and some time later, natural gas exceeds oil. This will mark the beginning of the Age of Natural Gas.
5) Oil keeps falling, and coal exceeds oil.
6) The Second Age of Coal: Natural gas peaks and falls, and some time later, coal exceeds natural gas, marking the beginning of the Second Age of Coal.
7) Decline: Coal peaks, and the fossil fuel era enters its final phase.