It may form an interesting intellectual exercise to imagine ways in which life might arise, and having arisen might maintain itself, on a dark planet; but I doubt very much that this has ever happened, or that it can happen.

George Wald, “Life and Light,” Scientific American 201, no. 4 (1959): 108.

Editor’s note: We are pleased to present a series adapted from biologist Michael Denton’s book, Fire-Maker: How Humans Were Designed to Harness Fire and Transform Our Planet, from Discovery Institute Press. Find the whole series here. Dr. Denton’s forthcoming book, The Miracle of the Cell, will be published in September.

Because of its atmosphere, its size, and its abundance of metals, the Earth is the right kind of planet to supply a home for a fire-making creature who can create new technologies. But there is another aspect of the Earth’s environment that is absolutely crucial in allowing the utilization of fire for metal-based technologies. 

To make a fire sufficiently hot to smelt metals requires the right fuel. 

Thin twigs and dried grasses will burn, but such materials are unsuitable for making hot, sustainable fires that can reach high enough temperatures (many hundreds of degrees) to smelt metals from their ores. Wood or wood products such as coal, charcoal, or coke are the only fuels that will do. Without large trees, there would be no wood, no charcoal, no coal (essentially fossilized wood), and no sustainable fires for smelting metals. Prometheus would be well and truly bound.

Thanks to Human Inventiveness? Nope

Again, it was not human inventiveness that provided either the wood for the manufacture of the charcoal that fired the primitive kilns in which the first metals were smelted nor provided the vital oxygen to burn the charcoal. The existence of wood (and nearly all the organic material on Earth) and the oxygen in the atmosphere are the gifts of photosynthesis, the process by which green plants utilize the energy of sunlight to synthesize reduced carbon compounds which form the substance of wood and draw the hydrogen from water to release oxygen into the atmosphere. As Stephen Pyne points out: 

Fire on Earth is a pervasive feature of the living world. Life created the oxygen that combustion requires, and provides the hydrocarbon fuels that feed it… Fire takes apart what photosynthesis has put together; its chemistry is a bio-chemistry. Fire is not something extraneous to life to which organisms must adapt, it is something that has emerged out of the nature of life on Earth.¹

The fitness of nature for photosynthesis is a fascinating topic which I cannot do full justice to here, but suffice to say that it depends on the atmosphere letting through the “right” visual light and absorbing the “wrong” dangerous radiation in UV, gamma, and X-rays regions of the electromagnetic spectrum. The visual light energy raises the electrons in chlorophyll to higher energy levels which  escape from the chlorophyll and flow down electron transport chains  providing energy for the synthesis of organic compounds in the chloroplast . At the same time, it creates a charge separation, drawing electrons from water, oxidizing it, and releasing oxygen.² Altogether photosynthesis is a remarkable process which may even necessitate exploiting a process called quantum tunneling.³

Next, “The Role of Lignin for Fire, Explained.”

Notes

1. Stephen Pyne, “The Ecology of Fire,” Nature Education Knowledge 3, no. 10 (2010): 30, http://www.nature.com/scitable/knowledge/library/the-ecology-of-fire-13259892.
2. Tim Lenton, Revolutions That Made the Earth (Oxford: Oxford University Press, 2011), Chapter Eight. 
3. Johnjoe McFadden and Jim Al-Khalili, Life on the Edge: The Coming of Age of Quantum Biology (New York: Crown Publishers, 2014), Chapter Four.