Something I keep coming back to when thinking about climate change: Was it inevitable or did we really mess up? If we copy pasted the Earth a hundred times and reset the clock to the year 1000 AD, would the humans on all of those iterations of Earth also find themselves staring down a climate crisis in 2021? Obviously there’s no scientific way to think about this. We know from chaos theory that something as trivial as when a butterfly flaps its wings can be the difference between a catastrophic tornado or a mild breeze. But surely some patterns would emerge if we could do it all over again a hundred times, or a thousand times. From a systems perspective, there’s the initial conditions and then there’s the rules that define how everything works. Sometimes bad initial conditions can snowball into a suboptimal state that’s hard to change but other times the rules of the system will yield the same outcome no matter where we start. Butterflies don’t always cause tornadoes, but warm moist air running into cool dry air is a pretty reliable formula for creating them. It’s fair to ask why does this thought experiment matter if we can’t try again and are stuck with the problems we’ve created? It matters because it can provide grounds for optimism. While we can’t change the past, if we believe human created climate change isn’t completely predetermined then it should give us hope that we can meaningfully shape our future. So here’s an attempt to answer this question of inevitability across a few different sectors.
Humans would invariably end up using fossil fuels in some capacity in every copy paste iteration of the Earth. The rule at play here is that there are very few substances as energy dense, accessible, and transportable as coal and oil. Reinforcing that rule is the biological imperative of humans to expend as little energy as possible in order to survive and reproduce. In our modern world vegging out on the couch causes physical and mental health issues but for most of human history that has been the ideal state: To reduce energy output and increase energy input. Fossil fuels are amazing at helping to do just that. A society with fossil fuels can move away from converting solar energy into muscle power (in the form of food) thereby saving themselves a great deal of energy output. In place of muscle power they can convert stored chemical energy (fossil fuels) into mechanical power. Usage of fossil fuels is definitely something that happens no matter who invents the steam engine or where oil is first put to use. Now assuming that humans are bound to use fossil fuels, would they have any ability to control how much gets burned? In addition to being wired to conserve energy humans are also predisposed to prioritizing the short term over the long term. We’re all just kids from the famous marshmallow study showing that delayed gratification is something that’s hard to practice. This evolutionary benefit of shortsightedness also seems like a rule that would repeatably result in more and more fossil fuel usage as the number of humans increased. Give an organism an easily exploitable energy source and what else should we expect? Where it gets more interesting and seemingly less predetermined is the human ability to go beyond short-term thinking. Once humans on a different iteration of Earth discovered the greenhouse effect and its relation to fossil fuels, what would they do? This seems dependent on those fateful butterfly wings given how varied any other iteration of Earth would be. In our own history we came surprisingly close to taking action on the problem between 1979 - 1989 as this fantastic piece by Nathaniel Reich explains. Unfortunately no substantive change happened and 50% of all emissions have happened since 1990. So at the broad intersection of energy dynamics and evolutionary tendencies there is a level of inevitability to the climate crisis. The wiggle room comes from the extent to which humans could act against their biological imperatives in the face of how easy life with fossil fuels can be.
In the building materials sector (11% of total emissions) the analysis is similar to fossil fuel use because they’re connected by one material: concrete. It is a highly versatile material which is strong, durable, and producible almost anywhere on Earth. What ties it to fossil fuels is the manner in which concrete is made. More specifically the manner in which cement, the binding agent in concrete, is made. We make cement by collecting a bunch of limestone, heating it up to 1450 degrees Celsius, and then grinding it up into a powder. In a world where fossil fuels are plentiful, creating that high heat is easy and affordable. Modern Portland cement was invented in Britain by Joseph Aspdin in 1824. A big reason he was able to do so was the readily available coal found in England that could be used to heat up his kilns. The qualities of concrete make it hard to not use once it is discovered. Even before Portland cement, humans have been using natural cements to make concrete for ages. The Pantheon is over 2,000 years old and is still doing just fine. So here as well there seems to be a rule as opposed to a suboptimal state. If society is reliant on fossil fuels then it’s only a matter of time before it figures out how to make cement. And once it has cement, concrete has too many appealing qualities and will be poured anywhere and everywhere. Today concrete is the most consumed material in the world outside of clean water. The only crack so to speak would be how often on different iterations of Earth humans end up placing the same value on permanence and the associated desire to defy nature. While concrete is now dominant, humans have made structures out of natural materials for hundreds of years. And some of those non-concrete structures continue to remain standing. In a world where the cultures of the Mongols or the indigenous groups of North America remained prominent, the idea of permanent concrete structures may not have ever come into being. Ultimately however fossil fuel use and concrete aren’t easily separable. Therefore it's likely that most iterations of Earth would still end up with a lot of emissions from building materials.
The transportation sector (14% of total emissions) is less about any rules and more about the pathways by which societies develop. The fundamental question is how many iterations of Earth end up with the same culture of individual car ownership as our real world. Internal combustion engines (ICE) would surely develop given the properties of fossil fuels. A 100 kWh Tesla battery weighs 1300 pounds and has the same amount of energy as 3 gallons of gas (18 pounds). However, it’s unlikely that ICEs are are always implemented in the same way when it comes to enabling mobility for people. Individual car ownership traces its roots to the value America placed on individual freedom and the country’s geography which is defined by vast amounts of open space. This culture has been exported abroad and now can be found all over the place. No doubt in all iterations of Earth humans would want to move about in as convenient a way as possible. But the most efficient way of doing so would always be tied to the geography of the land and the living arrangements of the society (dense or spread out) where ICEs first grew prominent. That is to say, what would transportation look like if America wasn't the birthplace of the mass manufactured car? The public transit systems of cities like Shanghai, Tokyo, and Singapore prove that convenient mobility doesn’t require cars. The ways in which we move and live are so flexible and malleable that in each iteration we could expect huge variability in the dominant mode of mobility. There aren’t any properties of individual car ownership that seem durable to repeated trials. To make a claim that the same model of car ownership would always occur in every iteration of Earth is to make a claim that an emphasis on individual freedom is an innate feature to human development. And that doesn’t seem reasonable given the numerous cultures in our past and present that do not have the same emphasis.
The food sector (34% of total emissions) is easily the one that is least governed by any hard and fast rules of the universe. At the intersection of food and climate is the cow. Humans domesticated bovine species two independent times prior to the year 1000 AD. Cows are an integral part of humanity’s path to modern civilization. Despite that, it’s very clear that in our current world we are in an inefficient situation when it comes to our level of meat consumption in relation to its impact on the environment. Unlike other animals cows not only need vast amounts of land and water but also burp methane directly into the air. Humans had to incorporate meat into their diets around 250,000 years ago when a previous climate shift occurred. But even by the year 1000 AD meat consumption wasn’t a necessary condition for the survival of humanity. Our omnivorous abilities are prolific and allow us to live almost anywhere on the planet unlike other animals. There’s no path of least resistance that compels the levels of meat eating seen today. Food is culture and initial conditions matter a great deal in that regard. In America the rise of meat can be tied to the ample land available to raise livestock along with the relative lack of meat available to European immigrants in their original home countries. Irish settlers used to write back to their families exclaiming about their ability to eat meat everyday. Something unheard of in a country that was still recovering from the potato famine. This unique set of circumstances paired with the industrialization of America led to the rise of a meat industry that’s transformed but never slowed down. But for most of our history meat consumption has been just one portion of our diet and roughly 280 million people in India don't eat meat at all. While our culture today might be locked into a heavy meat diet, the case for this to be a repeating feature across iterations of Earth seems weak. Food is also behavior and behavior can be affected by even small perturbations.
Where does all this speculation leave us? So many variables have been left out and even if they weren't we'll never be able to actually create such copy paste simulations. I see this thought experiment as a practice in questioning why things are the way they are. Having a point of view on the enduring rules for how the world works helps with thinking about how the world might change in the future. In this version of Earth we have to contend with the lock-in effects of our bad initial conditions. A world without cars is possible, but how to get there from a world already filled with them? It’s tough, but not as tough as going from a world filled with concrete to one without it. And that’s why knowing where we’re facing a path of least resistance and where we aren't is important. Understanding the difference can help direct focus to areas where progress might be made more quickly. Humans despite our evolutionary shortsightedness are capable of adopting a huge variety of lifestyles. Tackling the problems where we can leverage that capability in order to reset some initial conditions through power of will is a good first step. We don’t get to rewind the clock and there aren’t any other iterations for us to do some trial and error. All we can do is keep asking questions and use the answers we come up with to chart a path away from the precipice of the climate crisis.
The closest thing to this thought experiment I’ve come across are articles suggesting that climate change is the Great Filter event that prevents civilizations from achieving interstellar travel as part of Fermi’s Paradox. The paradox in short form is that if other intelligent life in the universe is likely, then why have we found no evidence of it? The Great Filter is one answer - That there exists some unknown obstacle that prevents intelligent life from spreading across the stars. Climate change understood as a population exceeding the carrying capacity of its planet and then collapsing could be a Great Filter event. Can’t reach for the stars if you’re melting away on Earth.
This experiment is also useful for thinking about future developments. Some would argue we’re also at the precipice of a monumental shift in our monetary system. Moving from fiat currencies to proof-of-work backed cryptocurrencies. Should the future of our monetary system be tied to technologies that incentivize leveraging the cheapest energy available regardless of its source? Will we curse ourselves for choosing yet another suboptimal way of living if the promise of renewable powered cryptocurrencies never takes hold and miners continue to burn coal for power? It would be a travesty to look back in 50 years and see that our monetary system could have had a different solution but we opted for one that somehow managed to directly tie burning more fossil fuels to maintaining functionality. Understanding whether the rise of cryptocurrencies is a path of least resistance or just a result of strange initial conditions is worth some thought. To any crypto-fanatics, yes not all cryptocurrencies are backed by proof-of-work but clearly the biggest ones today are and Bitcoin seemingly will never move away from it.