This essay attempts to summarize every important topic discussed on this site, and is a work in progress that I frequently correct and expand as my understanding of the world improves. You might want to check back from time to time to read the latest version. I would appreciate readers pointing out any errors or omissions.

This is the story of the two most important things that enabled the success and possible demise of humans: energy and denial.

Simple single cell (prokaryotic) life emerges as a gradual and predictable transition from geochemistry to biochemistry, in the presence of rock, water, CO2, and energy, all of which are found within alkaline hydrothermal vents on geologically active planets, of which there are 40 billion in our galaxy alone, and probably a similar number in each of the other 100 billion galaxies.

Simple life like bacteria and archaea is therefore probably common throughout the universe. Strong evidence for this is that prokaryotes appeared 4 billion years ago, as soon as the earth cooled down enough to support life, and never once winked out despite many calamities throughout geologic history.

LUCA (the Last Universal Common Ancestor), and all life that followed, is chemiosmotic meaning that it powers itself with an unintuitive mechanism that pumps protons across a membrane. This strange proton pump makes sense in the light of its hydrothermal vent origins. For a sense of the scale of life’s energy, consider that the human body pumps a staggering 10**21 protons per second of life.

The transition to, and existence of, complex multicellular life, like plants and animals, is much less predictable and certain. All of the complex life on earth has a common eukaryote ancestor, and it appears this ancestor emerged only once on Earth about 2 billion years ago. This is a vital but rarely acknowledged singularity in biology.

The eukaryote cell was created by a rare endosymbiosis (merging) of prokaryotes (simple cells) somewhat analogous to a freak accident. The resulting LECA (Last Eukaryotic Common Ancestor), having 2 genomes that needed to cooperate and evolve in harmony, was probably fragile, sickly, and vulnerable to extinction which forced it to evolve many unusual characteristics common to complex life such as the nucleus, sex, two sexes, programmed cell death, germline-soma distinction, and trade-offs between fitness and fertility, adaptability and disease, and ageing and death.

As the endosymbiont (cell within the cell) evolved into mitochondria (energy powerhouses), eukaryotes were able to break through the energy per gene barrier that constrained the morphological complexity of bacteria and archaea for 2 billion years. Suddenly there was enough energy to power the evolution of complex structure, multi-cellular life, a symphony of fungi, plants and animals, and one single hominid with an extended theory of mind that took over the planet.

The magnificent and varied life we enjoy on Earth may not be unique in the universe, but is probably very rare, and our existence and ability to understand and discuss the origin of this life, is extraordinarily rare and precious.

Life at its core is chemical reactions that consume energy to replicate themselves. There is a minimum quantity of energy required to sustain life. This subsistence energy supports growth to sexual maturity, finding and winning a mate, reproducing, and feeding the offspring. It also includes the energy for shelter and clothing to create a hospitable environment for the chemical reactions to operate, energy to power the muscles used to evade or fight threats, and energy for the cells to repair damage from sickness or injury.

All of this subsistence energy must come from the surplus left after using energy to gather, hunt, grow, steal, or purchase energy. In other words, life must obtain more food than the food it takes to obtain food. Otherwise it dies. For example, if a coyote burns 2 rabbits worth of energy to capture 1 rabbit then it will die. If on the other hand, a coyote burns 1 rabbit of energy to capture 2 rabbits then it might be able to produce offspring that survive to repeat the achievement. Similarly, an ape that sells life insurance and uses its wages to buy food must be employed by a life insurance company that makes a profit. Without a profit the ape will lose its job and ability to buy food. Profit is an energy surplus.

Energy is required to produce anything and everything. For example, your coffee mug required diesel-powered machines to dig up and transport clay to a factory that used natural gas-fired furnaces to fuse the clay into a durable ceramic container that was then transported by a diesel-powered ship and diesel-powered trucks to a store that you drove to in a gasoline-powered car and purchased with wages your earned from a company that generated a profit by using energy to create something worth more energy. Money is a token we can exchange for real things. Therefore money is a claim on energy.

If a species finds a way to capture more energy than is required to subsist, then its probability of survival and population increases. Additional surplus energy is first used by life to increase fertility and decrease mortality. This makes intuitive sense because the chemical reactions at the core of life are replicators that replicate until some resource shortage constrains them. The most important resource, by far, is energy because with sufficient energy many other resource shortages can be overcome. For example, a well fed coyote can range farther to find water, and an ape can use natural gas generated steam to extract oil from sand.

Until recently all species obtained their energy from the current flow of sunlight (e.g. grass) or the recent flow of sunlight (e.g. wood). As an aside, a few species use instead chemical energy from geothermal processes but I will not discuss this since the ideas are analogous. An ape that eats a cow uses current solar energy via the photosynthetic grass eaten by the cow to produce flesh, and recent solar energy via the wood used to predigest (cook) the meat.

The sun shines at a relatively constant intensity and the earth is a fixed size at a relatively constant distance from the sun. Therefore the available sunlight on earth is finite and fairly constant. If one species captures more energy it must come at the expense of a different species. This tension is the driving force behind evolution.

The competition for finite resources as governed by the laws of evolution has created many amazing variations of life. For example, trees that grow tall to capture more sunlight than its neighbors, cheetahs that run faster than their prey, giraffes that eat high leaves, and birds that migrate with the seasons. One species emerged with a unique capability to out-compete all other species for available sunlight, and then used this same capability to break through the sunlight barrier.

About 100,000 years ago there were several intelligent social species of hominids spread around the world, all with about the same brain size and power. For some period of time, perhaps several million years, these species bumped up against evolving an extended theory of mind, which would have been advantageous for these social species because it enhances cooperation by enabling an individual to understand the minds of other individuals. Each time an individual was born with a mutation for an extended theory of mind they would have observed, through the normal course of daily activities like hunting and childbirth, other individuals being killed or injured, and therefore would have come to understand their own mortality. All animals have a very useful inherited behavior that causes them to fear and avoid injury, and therefore mortality awareness caused fear, depression, and risk avoidance, which reduced their reproductive fitness, and so the mutation for an extended theory of mind did not fix in the gene pool.

Then one day, through random chance, a member of one tribe in east Africa was born with a mutation for an extended theory of mind plus denial of reality. The two independently maladaptive behaviors, when improbably combined, became highly adaptive. The genes from that individual became fixed in her tribe and the resulting improvement to the tribe’s ability to communicate and cooperate increased the success of the tribe.

Having broken through the mortality barrier, it now became advantageous and probable for natural selection to evolve a larger and more powerful brain with complex symbolic language, planning and analytic skills, and increased memory capacity. An additional fortuitous side effect of denial of reality was the optimism bias it created which the intelligent species used to advance technology, hunt dangerous animals, wage war, and explore new continents.

This new species that emerged from a small tribe of hominids, that we now call human, and that is sometimes referred to as the chosen people, used its new abilities to out compete all other hominid species.

The mutation for denial of reality, which was essential for dampening the inherited fear of injury and death, caused each new human tribe to create life after death stories which served to define, unite, govern, and entertain the tribe. Thousands of different stories, which we now call religions, were created by thousands of tribes, with their one and only common feature being, due to its genetic foundation, a life after death subplot.

Over this same period of time, and probably even longer, there were other intelligent social species like chimpanzees, dolphins, elephants, and crows that were bumping up against the mortality barrier to evolving an extended theory of mind. Some of these species achieved partial theory of mind as demonstrated, for example, by behavior consistent with mourning their dead and revenge, however because of the improbability of mutating an extended theory of mind simultaneous with denial of reality, these species never evolved brains similar to humans.

The enlarging human brain soon became constrained by the size of the birth canal and associated pregnancy health risks. Because of the strong fitness advantage a larger brain provided, evolution found a clever way to work around the birth canal constraint by delivering babies with undeveloped brains. Therefore, as humans became smarter, parents were required to care for their offspring for a longer period before they became independent and able to breed. This led to other behavioral and cultural changes, such as pair bonding, and religions with stories that discouraged adultery.

The humans used their intelligence and social skills to develop technologies to capture a larger share of solar energy. Examples of these technologies include mastery of fire for cooking, heating, and land clearing; domestication of animals initially for protection and hunting assistance and later for transportation, agricultural labor, and sources of food; metal for weapons and tools; projectile weapons for extending its lethal range; replacement of indigenous plants with cultivated food plants; redirection and storage of water; methods and vehicles for migrating to all available continents and islands; shelter and clothing to survive in all climates; architectural structures for defense; and written language to store and transmit the technologies.

The human population increased rapidly and spread to all continents. Large prey went extinct everywhere shortly after the arrival of humans, except in Africa, where the large animals co-evolved with early humans. All of the humans’ close relatives were out-competed and went extinct. Human civilizations like the Egyptians, Romans, Mound Builders, and Mayans, experienced cycles of growth, overshoot, and collapse as they bumped up against the barrier imposed by finite solar energy.

Then, 200 years ago, humans used their intelligence to discover a new technology that fundamentally changed the rules. Humans learned how to exploit a new source of energy to augment finite sunlight. This energy is ancient buried biomass commonly called fossil energy. Unlike sunlight that is constrained to the real-time flow from the sun, fossil energy accumulated over millions of years and therefore acts as a giant solar energy battery. Now humans could not only exploit current solar energy (e.g. grass) and recent solar energy (e.g. wood) but also ancient solar energy (e.g. coal, oil, natural gas).

Because energy is the master resource that can be used to extract other resources, including more energy, fossil energy created a positive feedback driven 200 year period of explosive population, wealth, and technology growth. With surplus energy available to replace human labor with machines such as tractors and combines, fewer humans were required to work on subsistence activities and more humans could specialize in a wide variety of scientific, engineering, and cultural domains.

Food production was increased through the use of natural gas derived nitrogen fertilizer, oil based pesticides, diesel-powered tractors, combines, and irrigation, and diesel-powered trucks, trains, and ships to deliver it. More food enabled the population to increase from 1 billion to 7 billion. New technologies that used the surplus fossil energy improved the quality of human life such as housing, drinking water, sanitation, medical and dental care, communications, transportation, labor-saving machines, and entertainment. Humans used the surplus fossil energy to make amazing advances in science and technology including traveling to the moon and understanding the origin of life and its respiration, replication, and photosynthesizing chemical reactions, and invented light speed digital networked communications technology to share and discuss this understanding with other members of the species anywhere on the planet.

Some side effects of the new technologies also reduced the quality of life for some humans. These included health problems caused by pollution and the new abundance of delicious but unhealthy foods such as sugar that were evolutionarily scarce.

Almost all other species, except those cultivated or domesticated by humans, and those that piggyback on the success of humans, like rats, suffered from the success of humans. The rate of species extinction increased to unprecedented levels. Rather than using fossil energy to replace sunlight energy, thereby freeing some energy for other species, humans used fossil energy to add to the solar energy they already commanded, and most wild species declined. Fast and powerful fishing boats capable of scooping and scraping all life from the ocean anywhere on the planet are one of many examples.

The purpose of the universe, if it can be said to have a purpose, is to increase entropy. The universe abhors an energy gradient and life is its best invention for degrading energy gradients. Humans are the champions of life at degrading energy, and from this perspective, may be the universe’s pinnacle of invention.

Conflict between tribes is a persistent feature of human history with periods of calm and periods of extreme violence. The inherited denial of reality enables a high level of violence without the temper of empathy because tribes with different gods are viewed as lesser humans. For example, one large civilized tribe exterminated millions of “inferior” humans using gas chambers. Another large civilized tribe routinely kills innocents labeled as terrorists with automated drones to protect sources of fossil energy while telling itself it is spreading democracy.

There are three dark clouds looming over human success.

First, climate change and pollution.

The use of fossil energy releases CO2 into the atmosphere which acts as a blanket to trap solar energy which increases the temperature of the planet. Human released CO2 has already increased the earth’s temperature by about 1 degree resulting in many problems including droughts, storms, ice loss, and sea level rise. The CO2 already released by humans guarantees another 1 degree of rise, even if all fossil energy emissions were stopped today. It is now clear that the 2 degree limit agreed by many countries is not a safe target and is in fact very dangerous for civilization. Worse still, probable future human emissions will cause a 4-6 degree rise which raises the possibility of human extinction.

Sea level rise predictions from melting ice on Greenland and the Antarctic increase with each new study. At least a meter of sea level rise by the end of the century is now probable and subsequent predictions are expected to worsen. This is a significant problem because much important land for agriculture and cities is near sea level. There will be heartbreaking refugee migrations, starvation from decreased food production, and loss of capital property this century.

CO2 also acidifies the ocean which harms many species such as shellfish and corals, both of which are in sharp decline. Another large and widely unrecognized problem is that byproducts of fossil energy combustion create ozone which harms plants and trees. There is evidence that trees are in global decline. This should concern humans for many obvious reasons. One not so obvious reason is that planting trees is one of the few things humans can do that might succeed in removing CO2 from the atmosphere. If trees are being killed by the same activity that puts CO2 in the air then this strategy will not work.

Climate change is a wicked problem. A rising temperature creates other self-reinforcing feedback loops such as ice loss and methane release which act to further increase the temperature. At some point these feedback loops may dominate over human influences thus eliminating any ability for humans to affect the outcome. No one knows for sure, but we may be near or passed this tipping point.

Choosing to act on climate change in a meaningful way will also create new problems. Wealth is proportional to energy consumption. More specifically, $1 US adjusted for inflation to 1990 equals about 10 mW of energy. Over 90% of our energy comes from fossil energy. Therefore any meaningful reduction in CO2 emissions must shrink the economy, and because we have a debt backed fractional reserve monetary system with a large and rising quantity of outstanding debt, a meaningful reduction in CO2 emissions will probably cause an economic depression, at best. Thus a political platform promising to actually do something about climate change is unlikely to be elected, or re-elected.

Furthermore, a decline in economic activity will result in a rapid reduction of aerosols that currently mask some UV radiation resulting in a warming impulse of about 0.5 degrees thus making climate change worse in the short-term.

Second, finite and non-substitutable fossil energy.

The fossil energy that supports 7 billion humans is finite and rapidly depleting. The easy low cost oil is gone. The oil that remains, while substantial, is expensive, and becoming more expensive to find and extract. Each year it takes more energy to produce the same quantity of energy.

The fossil energy that remains is also dirtier and creates more pollution and CO2.

As the cost of energy goes up, the amount of energy society can afford to leverage productivity goes down. Thus productivity and incomes are falling at the same time that the cost of producing energy is increasing. This is the root cause of the worldwide economic problems that began in 2008 and persist today.

The price of energy required for energy companies to produce the quantity of energy necessary to maintain our current standard of living is now higher than society can afford. We have masked this problem with near zero interest rates and a huge increase in debt. These are temporary solutions that will soon be overridden by the laws of thermodynamics and mathematics, and will most likely end with an economic depression more painful than that had we chosen to take our medicine in 2008.

Think of a coyote forced, because rabbits are becoming faster, to burn 2 rabbits worth of energy to catch 1 rabbit. Even though there are plenty of rabbits, the coyote is in serious trouble. The coyote could switch his diet to mice (solar & wind energy) but then he’d have to burn 3 mice of energy to catch 1 mouse. The coyote is able to lead a fairly normal life for a while because he burns fat (debt) that he built up in previous good years. The coyote knows it could make do with less food if it quit fighting, played slower games, and had fewer pups, but prefers not to change its lifestyle. Over time, the coyote becomes weak and sick, and then decides to change, but no longer has the strength to catch even mice.

Any system in nature, including human civilization, is sustainable only if it survives on the interest generated by the capital of the system. For example, bison on prairie is a sustainable system surviving on the interest generated by sunlight, soil, and rainfall. Replacing the bison and grass with wheat fertilized with natural gas generated nitrogen and irrigated with diesel pumped non-renewable aquifers converts the capital (soil, aquifer, and fossil energy) into income (calories).

Debt at near zero interest rate is a means of converting capital into income. Our recent increase in debt can therefore be viewed as energy that would otherwise have been available to future generations. We are aggressively impoverishing our grandchildren (and other species) in an attempt to maintain our current privileged lifestyles.

Depleting fossil energy is a wicked problem. A law of thermodynamics states that energy cannot be created. The battery we have been relying on is running low and will take millions of years to recharge, and may never recharge unless the planet’s biological and geological processes realign in the necessary and fortuitous configuration that created fossil energy the first time.

Renewable energies such as wind and solar do not have the density, scalability, or storability necessary to replace the fossil energy humans currently depend on. Most importantly, we do not have a viable alternative to the diesel that powers our critical life support network of trucks, trains, ships, tractors, combines, and mining machines. If trucks stop running, for any reason, all of civilization will be in immediate and extreme danger.

Renewable energies cannot stand on their own without fossil energy to create, install, and maintain their materials and infrastructure. For example, wind turbines use large quantities of concrete, steel, and copper that cannot be made without fossil energy. Renewables are at best fossil energy extenders. At worst they accelerate economic growth and burn up the remaining fossil energy faster to capture some wind or solar energy with equipment that will wear out in less than 50 years when there will be little or no fossil energy needed to replace the equipment.

Nuclear energy has the required density and scalability but lacks the storability necessary to replace vital diesel discussed above. In addition, current nuclear technologies rely on non-renewable and possibly peaked uranium fuel, plus non-renewable fossil energy for infrastructure, materials, transportation, construction, and maintenance. Future nuclear technologies might address these shortcomings but are many years and trillions of dollars away from deployment. Finally, and perhaps most importantly, the combined threats of climate change, fossil energy depletion, and limits to growth caused economic instability, make it a very dangerous bet that we will be able to properly govern and maintain nuclear facilities in the future.

Third, denial of reality.

Humans succeeded as a species due in large part to their evolved denial of reality. This behavior is now a disadvantage because it prevents the majority of humans from recognizing and acting on climate change and fossil energy depletion. It is noteworthy that there is not one senior leader in any country on any continent that has publicly communicated an understanding of what is going on and what we should be doing at this time, even after leaving office. Likewise, all groups including climate scientists, climate deniers, fossil energy experts, renewable energy experts, environmentalists, capitalists, socialists, communists, conservatives, liberals, Christians, Muslims, Scientologists, you name it, everyone is in denial about human overshoot. This is of course what we should expect given the genetic basis for denial. But it is nevertheless a concern.

The human brain, the God it believes in, and the overshoot it enabled and denies, all resulted from the same improbable genetic adaptation that occurred about 100,000 years ago.

What should we do?

There are no painless solutions to our predicament. The problems are wicked and politically intractable:

problems are complex and difficult to understand;

there are no easy or short-term solutions;

solutions that improve the long-term are likely to worsen the short-term;

solutions usually conflict with evolved human behavior;

some problems are out of our control.

We are in a severe state of overshoot which guarantees some form of bottleneck and collapse. Our aim should be to slow the descent and prepare a softer landing zone.

Despite the depletion of fossil energy we still have a lot more surplus energy than is required for subsistence. Remaining surplus energy should be redirected from activities that have no future such as air travel, automobiles, military, and advanced technology; and towards infrastructure and skills that will be required in a simpler low energy world such as local food production, resilient water supplies, and energy conservation.

Policies should be implemented to reduce the population as quickly and humanely as possible. Paraphrasing Albert Bartlett, there is no problem on the planet that does not improve with fewer people.

After the inevitable economic reset, a new monetary system will be required, preferably an energy-backed full-reserve system, as we move into a long-term energy constrained contracting economy. Wealth redistribution and rationing policies should be developed in anticipation of their need.

Citizens should be proactively educated on the root causes of our problems to avoid inappropriate blame and wars which will only worsen the situation by accelerating the depletion of non-renewable resources.

What will we do?

Evolved denial of reality will probably continue to block any constructive discussion or proactive action. When a crisis forces action we will probably blame the wrong actors. Our responses are not likely to be rational or optimal. Expect chaos.

A few people have broken through inherited denial. So it is possible. But scaling this to the majority will be a challenge.

The singular emergence of human intelligence, and its ability to write and read this paragraph, evolved in a gene controlled machine with an unusually powerful computer, that was created by an improbable simultaneous adaptation for an extended theory of mind with denial of reality, and whose complexity was enabled by the increased energy per gene provided by mitochondria, that resulted from an accidental endosymbiosis of two prokaryotes, powered by an unintuitive chemiosmotic proton pump, that originated in an alkaline hydrothermal vent, on 1 of 40 billion planets, in 1 of 100 billion galaxies, and that planet had an improbable store of photosynthetic and geothermal generated fossil energy, that the species leveraged to understand and appreciate, the peak of what may be possible in the universe, before it vanished, because it denied the consequences of its success.

A good place to go next is Why My Interest in Denial?