oxygen while fixing atmospheric carbon. For the most part, carbon and hydrocarbons, which are converted by photosynthesis, are oxidized in the years after the plant or animal dies. However, a small fraction can be subjected to anoxic conditions in which this can’t occur. This sediment becomes buried deeper and deeper as time passes. Coal is the result of millions of years of pressure and heat on ancient phytomass. Oil is mostly dead sea organisms (called diatoms, pictured above) which settled on ancient seabeds, were buried, and then subjected to heat and compression over long spans of time.
As it was compressed and heated at its increasing depth, lighter and more volatile compounds, like oil and natural gas, tended to flow upwards to the surface and oxidize. Only when they were prevented from migrating all the way to the surface by “structural
caps” of impermeable strata, did oil and gas accumulate in porous rock which could one day be tapped by conventional oil and gas wells. Nature did most of the work for us – all we had to do was find, extract and refine this biotic resource from the past. We started commercially mining coal in 18 th century England, oil in Pennsylvania in 1859 and natural gas in the mid-20 th century. In under 200 years, we are accessing and breaking these carbon bonds 10 million times faster than they were originally sequestered. Why? Because it’s powerful stuff. And because we can. TaaL: My species was fortunate. Our wor ld’s geology did not create a “carbon trap” to be sprung by a clever species like Earth did. Long before my people evolved, bacteria and insects which digested cellulose prevented coal beds from forming on my world. Otherwise, my species would likely have wrecked the planet in pursuit of short-term goals before maturing into a sapient species. Chance accidents of bacteria gave us the time to develop sapience long before we developed a thirst for exosomatic energy. The reasons we refer to worlds such as your s as having a “carbon trap” is that geological processes and random chance create a nearly irresistible prize for any species which learns to want exosomatic energy, a prize whose use
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