That decline in whaling EROI and the gross amount of exploitable whale oil set the stage for exploiting a new energy source, and the then happened. Oil’s EROI and total exploitable energy made whales insignificant by comparison. In the 1930s, the EROI for East Texas oil wells was . Those days of easy oil are long gone. The global EROI of oil and gas production has fallen from about 30 in 1990 to less than 20 in 2014 and may decline to 10 by 2020. That means increasing amounts of energy are expended to extract the energy. Reports of increasing gross global energy extraction are misleading, as the more important measure is net energy acquired. At an EROI of two, half the energy acquired is used for extracting it. At a gross 100 barrels of oil extracted at an EROI of 100, 99 barrels are available for societal use. At a gross 100 barrels of oil and an EROI of two, only 50 barrels are available. Only about a third of an oilfield’s deposit is recoverable. Once a third of the oil is extracted, the energy surplus quickly falls to zero and it takes as much energy to extract the oil as is acquired, or stated another way, the EROI falls to one.
For the first concept presented above, for conventional renewable energy sources, they are replenished by sunlight or radiation from Earth’s interior; one is fusion, and the other is fission. For so-called non-renewable energy sources, such as hydrocarbons and fissile materials, they are either renewed on timescales so vast that they are effectively non-renewable for humans (such as ), or are “renewed” by the (fissile materials), so could only be renewed with new planetary formation. In mainstream thought, the currently non-renewable energy resources are primarily hydrocarbons (petroleum, coal, and natural gas) and uranium. Much of the debate centers around the definition of oil. What has been called oil for the past 150 years is today called . It is the oil formed by the , and can be mined by drilling wells and extracting it with the conventional methods that have been used since the beginning, and new techniques are periodically invented to increase the rate and total extraction. For conventional oil, humanity has unearthed about 1.1 trillion barrels since 1859, and about as of 2014. Production of conventional oil peaked in 2006 at 25 billion barrels per year and has declined since then. At current production rates, conventional oil will be completely depleted in less than 50 years. About another five billion barrels per year are called unconventional oil, which is called heavy oil, extra heavy oil, and oil sands. Those unconventional oils comprise trillions more barrels, and total and arguably more. For fissile materials, primarily uranium, the peak may have already been reached by 2014, or it . For , in that the peak may have already been reached, or it is only a few decades into the future at most. For coal, may also be only a few decades into the future. Peak extraction usually occurs when about half of the recoverable energy resource has been mined. In summary, the energy resources that have powered the Industrial Revolution are all on their way to largely vanishing in this century. The only resources with seeming viability past this century are coal and unconventional oil, which brings us to the second concept: .
Since the most dramatic instances of speciation seem to have happened in the aftermath of mass extinctions, this essay will survey extinction first. A corollary to is that if any critical nutrient falls low enough, the nutrient deficiency will not only limit growth, but the organism will be stressed. If the nutrient level falls far enough, the organism will die. A human can generally survive between one and two months without food, ten days without water, and about three minutes without oxygen. For nearly all animals, all the food and water in the world are meaningless without oxygen. Some microbes can switch between aerobic respiration and fermentation, depending on the environment (which might be a very old talent), but complex life generally does not have that ability; nearly all aerobic complex life is oxygen dependent. The only exceptions are marine life which has adapted to . Birds can go where mammals cannot, , for instance, or being , due to their . If oxygen levels rise or fall very fast, many organisms will not be able to adapt, and will die.
Charles Morgan, a shipper in New Orleans in the eighteen-fifties and sixties, was so irritated by New Orleans’ taxes, New Orleans’ dockage fees, and New Orleans’ waterfront clutter that he moved his operation to the Atchafalaya and developed a competing city. It seems unlikely that he was aware that the Mississippi River meant to follow him. Morgan City thrived on shipping, on oysters. When the big cypresses were felled in the Atchafalaya swamp, Morgan City became the center of the cypress industry in the United States: numerous sawmills, hundreds of schooners in the port. Brownell’s great-grandfather owned a sawmill. In the nineteen-thirties, Captain Ted Anderson, a Florida-based fisherman, was blown off course by a storm, and put in at Morgan City. In the hold of his boat were shrimp of a size unfamiliar in Morgan City—big ones, like croissants, from far offshore. They were considered repulsive, and at first no one wanted them, but these jumbos of the deep Gulf soon gave Morgan City the foremost shrimp fleet in the world. As the Atchafalaya River pushed back the salt water, it pushed out of the marshes the nurseries of shrimp. Caught in the westbound littoral drift, the shrimp went to Texas, where much of the business is now. The growth of cypresses was too slow to keep up with the lumber industry, so the lumber industry collapsed. The next boom was in oil. The big offshore towers come out of the marshlands surrounding Morgan City. They are built on their sides and dominate the horizon like skeletons of trapezoidal blimps. Of the twelve hundred and sixty-three permanent platforms now standing in the Gulf on the continental shelf, eighty-eight per cent are off Louisiana.
Before the rise of humanity and industrial agriculture, the interplay of life, climate, and land masses created the that fed oceanic ecosystems. However, during the Cambrian Explosion the land was largely barren, as life had yet to significantly invade land. Also, have always been key hosts for oceanic ecosystems, as sunlight could reach the seafloor and nutrients were closer to the surface. When supercontinents broke apart or formed as the tectonic plates danced across Earth’s crust, shallow seas were often created, which were usually quite life-friendly. Those ancient shallow seas and swampy continental margins have great importance to today’s humanity, as our fossil fuels were usually created there. Earth’s were created in swampy floodplain conditions, usually near coasts, and the oil deposits were created by and that . The and its predecessors (, ) had a half-billion-year history that began in the Ediacaran, and the Tethys finally disappeared less than 20 mya. The shallow margins of those tropical oceans, and the anoxic events that dotted the eon of complex life, formed most of today’s oil deposits, and . Numerous shallow tropical seas .
In Paleocene oceans, sharks filled the empty niches left by aquatic reptiles, but it took coral reefs ten million years to begin to recover, . As Africa and India moved northward, the shrank, and in the late Paleocene and early Eocene, one of the last Tethyan anoxic events laid down Middle East oil, and the last Paleocene climate event is called the (“PETM”). The PETM has been the focus of a great deal of recent research because of its parallels to today’s industrial era, when carbon dioxide and other greenhouse gases are massively vented to the atmosphere, causing a warming atmosphere and acidifying oceans. The seafloor communities suffered a mass extinction and the PETM’s causes are uncertain, but the when the global ocean warmed sufficiently is a prominent hypothesis. Scientists also look to the usual suspects of volcanism, changes in oceanic circulation, and a bolide impact.
So far in this essay, mammals have received scant attention, but the mammals’ development before the Cenozoic is important for understanding their rise to dominance. The , called , first , about 260 mya, and they had key mammalian characteristics. Their jaws and teeth were markedly different from those of other reptiles; their teeth were specialized for more thorough chewing, which extracts more energy from food, and that was likely a key aspect of success more than 100 million years later. Cynodonts also developed a secondary palate so that they could chew and breathe at the same time, which was more energy efficient. Cynodonts eventually ceased the reptilian practice of continually growing and shedding teeth, and their specialized and precisely fitted teeth rarely changed. Mammals replace their teeth a . Along with tooth changes, jawbones changed roles. Fewer and stronger bones anchored the jaw, which allowed for stronger jaw musculature and led to the mammalian (clench your teeth and you can feel your masseter muscle). Bones previously anchoring the jaw were no longer needed and . The jaw’s rearrangement led to the most auspicious proto-mammalian development: . Mammals had relatively large brains from the very beginning and it was probably initially . Mammals are the only animals with a , which eventually led to human intelligence. As dinosaurian dominance drove mammals to the margins, where they lived underground and emerged to feed at night, mammals needed improved senses to survive, and auditory and olfactory senses heightened, as did the mammalian sense of touch. Increased processing of stimuli required a larger brain, and . In humans, only livers use more energy than brains. Cynodonts also had , which suggest that they were warm-blooded. Soon after the Permian extinction, a cynodont appeared that may have ; it was another respiratory innovation that served it well in those low-oxygen times, functioning like pump gills in aquatic environments.
The grew , and there were no more island barriers on the Tethys’s east end. The was finally squeezed out of existence by islands that became part of Eurasia. The shallow margins of the Tethys became the greatest oil source in Earth’s history. The and Paleo-Tethys oceans also formed oil deposits, but about initially formed during the Mesozoic’s anoxic events, primarily along the Tethys’s margins. In the Middle East, Caspian Sea, Western Russia, North Africa, Gulf of Mexico, and Venezuela virtually all of the oil deposits were laid down by dying and preserved organisms along Tethyan shores. In the early Triassic, along the west end of what became North America, oceanic plate subduction under continental plates that continue to this day. The foundations of the Sierra Nevada mountain range were formed then. I have spent .
The ecosystems may not have recovered from Olson’s Extinction of 270 mya, and at 260 mya came another mass extinction that is called the mid-Permian or extinction, or the , although a recent study found only one extinction event, in the mid-Capitanian. In the 1990s, the extinction was thought to result from falling sea levels. But the first of the two huge volcanic events coincided with the event, in . There can be several deadly outcomes of major volcanic events. As with an , massive volcanic events can block sunlight with the ash and create wintry conditions in the middle of summer. That alone can cause catastrophic conditions for life, but that is only one potential outcome of volcanism. What probably had far greater impact were the gases belched into the air. As oxygen levels crashed in the late Permian, there was also a huge carbon dioxide spike, as shown by , and the late-Permian volcanism is the near-unanimous choice as the primary reason. That would have helped create super-greenhouse conditions that perhaps came right on the heels of the volcanic winter. Not only would carbon dioxide vent from the mantle, as with all volcanism, but the late-Permian volcanism occurred beneath Ediacaran and Cambrian hydrocarbon deposits, which burned them and spewed even more carbon dioxide into the atmosphere. Not only that, great salt deposits from the Cambrian Period were also burned via the volcanism, which created hydrochloric acid clouds. Volcanoes also spew sulfur, which reacts with oxygen and water to form . The oceans around the volcanoes would have become acidic, and that fire-and-brimstone brew would have also showered the land. Not only that, but the warming initiated by the initial carbon dioxide spike could have then warmed up the oceans enough so that methane hydrates were liberated and create even more global warming. Such global warming apparently warmed the poles, which not only melted away the last ice caps and ended an ice age that had , but deciduous forests are in evidence at high latitudes. A 100-million-year Icehouse Earth period ended and a 200-million-year Greenhouse Earth period began, but the transition appears to have been chaotic, with wild swings in greenhouse gas levels and global temperatures. Warming the poles would have lessened the heat differential between the equator and poles and further diminished the lazy Panthalassic currents. The landlocked Paleo-Tethys and Tethys oceans, and perhaps even the Panthalassic Ocean, may have all become superheated and anoxic as the currents died. Huge also happened, which may have and led to ultraviolet light damage to land plants and animals. That was all on top of the oxygen crash. With the current state of research, all of the above events may have happened, in the greatest confluence of life-hostile conditions during the eon of complex life. A recent study suggests that the extinction event that ended the Permian may have lasted only 60,000 years or so. In 2001, a bolide event was proposed for the Permian extinction with great fanfare, but it does not appear to be related to the Permian extinction; the other dynamics would have been quite sufficient. The Permian extinction was the greatest catastrophe that Earth’s life experienced since the previous supercontinent existed in the .