You can't power a spacefaring civilization with fossil fuels
When humans first set foot on distant worlds outside our solar system, their ships won't run on gas. Spacefaring human civilization, by definition, cannot be powered by fossil fuels.
This cognitive dissonance is difficult to handle for environmentalists and oil executives alike:?Fossil fuels are simultaneously (1) a critical force for human prosperity without which the industrial revolution could never have happened and (2) a dangerous and impractical way to power a civilization beyond a certain point.
The large-scale, efficient burning of fossil fuels for energy is one of the greatest accomplishments of humankind. But we must soon discard this accomplishment in favor of another if we want to leave the cradle of Earth and become an enduring civilization.
Here are a few reasons why:
All energy is solar energy
The ancients were correct to ascribe celestial importance to the constellations they saw above.
The stars are the powerplants of the universe. They emit radiation when they burn, creating little islands of heat in a universe that is 99.99% cold, dark, empty blackness. Just like volcanically active undersea vents are thought to have been the birthplace of the earliest life forms on Earth, we might imagine stars play a similar role at the galactic scale, with life and other energy-dependent processes only able to occur within their little solar fiefdoms.
But stars are much more than that. They are the crucibles of complexity that manufacture the building blocks of planets, life, you, me, and the machine you are reading this on. Hydrogen, helium, lithium, beryllium, and boron are the only elements that occur naturally in the universe without the help of stars. Every other natural substance—iron, carbon, copper, oxygen, and hundreds more—can only be manufactured in the belly of a star where the temperature and pressure are enormous. When stars explode in a supernova, they scatter these materials into space to form new stars, planets, asteroids, and nearly everything else.
This is all to make a simple point: All energy is ultimately solar energy.*
Fossil fuels are no exception. Coal and oil are simply chains of energy-storing hydrocarbons from ancient plant and animal matter, formed through photosynthesis powered by the sun and then compressed over the eons. Even wind energy is solar energy, because winds are created by temperature imbalances on the Earth’s surface that result when certain areas (like the equator) receive more solar radiation.
Photosynthesis gives birth to young hydrocarbons (photo)
At the most basic level, it makes sense that more advanced civilizations would be able to capture star energy directly from its source, rather than through the clumsy intermediaries of compressed hydrocarbons. Based on this principle, many scientists and futurists like to categorize potential civilizations in terms of the scope of energy they can harness. This is known as the Kardashev scale and is possibly one of the coolest ideas cooked up by our fellow humans.
It goes something like this. A Type I civilization has tapped the energy resources of an entire planet, including the fossil, solar, and wind resources generated by its neighboring star. A Type II civilization can capture the total energy of that star directly, perhaps by construction of a Dyson sphere or similar structure. And a Type III civilization has harnessed all the energy in its native galaxy, either by applying the same Type II methods to all stars in the galaxy, or by tapping directly into the energies of the supermassive black holes thought to reside at the core of many galaxies. More imaginative thinkers than Kardashev have expanded the scale even further, including Type IV civilizations that have mastered the energies of an entire universe, and Type V civilizations that can bend the multiverse to their will.
A Type II civilization under construction (photo )
According to some back-of-the-envelope musings by Carl Sagan and others, that would make today’s humanity approximately a Type 0.7 civilization. Let that thought settle in for a moment. Despite all of our self-congratulations at having invented the Internet and landed on the moon, our infant race has not even made it to first base in the great cosmic energy race. But to our credit, we are picking up speed.
Viewed through this lens, the argument that fossil fuels are somehow here to stay feels shortsighted, wrong, and frankly a little boring.
And you thought they smelled bad on the outside
Fossil fuels are, for lack of a better word, a miracle substance. Nowhere else on Earth or beyond have we discovered so much energy, packed into such a concentrated package, that can be accessed so easily.
The technology to turn the chemical energy in fossil fuels into usable energy is simple in principle. All you need to do to create electricity is burn the fuel, use the heat to boil water, push the resulting steam through a turbine, and generate electricity from the motion of the turbine. Burning the fuel directly in lamps to generate light, in stoves to produce heat, or in engines to generate motion is even simpler. But without these innovations brought about by the miracle of fossil fuels, the momentum of the Enlightenment would have plateaued and humanity would have remained a dark, relatively non-productive agrarian society. It seems ridiculously fortunate that we evolved on a planet with such a plentiful supply.**
Unfortunately, the miracle of fossil fuels is revealed to be limited when we expand our viewpoint beyond the terrestrial. Despite the upsides, these fuels also have what might be called a crippling trifecta of downsides:
The combination of these three downsides essentially guarantees that fossil fuels are suited only for Type I civilizations, as shown here:
The trifecta of fossil fuel downsides
Each combination of downsides produces an undesirable limitation.
First, fossil fuels are not practical for propulsion over long cosmic distances. They must be stored on the vehicle that is burning them, and the combination of storage tanks plus the fuels themselves add significant weight. This in turn requires more fuel to push the added weight, creating a vicious cycle. To make matters worse, they burn off quickly and must be replenished. Even the most fuel efficient cars, ships, and planes must refuel frequently to be of any use. In the depths of space, refueling opportunities are rare and weight is at a premium. Fossil fuels may work like a charm for intra-solar system travel, but beyond that, they become a liability.
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Second, even if we manage to find our way to other planets, reliance on fossil fuels doesn’t bode well for the operation of off-world colonies. Weight is again a major issue here—if propelling heavy fuels through space is an issue, then landing them on a planet or asteroid is even harder. This may not be a deal-breaker if we could reliably expect fossil fuels to be present on every planet we hope to colonize, but their rarity is the final nail in the coffin. We have many reasons to believe that most planets we visit will not have any on offer. If we do occasionally stumble on a planet that once held life and has fossil fuels available, we’ll likely regard this as a bonus rather than a prerequisite for colonization.***
Third, once we become a multi-planetary civilization, the rare and finite nature of fossil fuels limits how much total energy they can provide before being exhausted. Imagine a world a couple hundred years into the future where humanity has colonized every feasible body in our solar system. Our population likely numbers in the high billions unless there has been a major reversal of demographics. We are ready to begin sending probes, colony ships, and maybe even von Neumman machines off in every direction to seek new worlds and new resources. It’s like the Age of Sail 2.0, perhaps literally if solar sails turn out to have promise as interstellar propulsion systems. Meanwhile back home, we’re conducting increasingly advanced high-energy physics experiments to see if it’s possible to overcome the physical limitations of the universe and unlock wormholes, warp drives, FTL systems, or whatever the buzzword of the day may be.
Such a civilization would be incredibly energy-hungry. To put things into context, it’s estimated by BP that the total energy content of all proven fossil fuels on Earth in 2015 was 1,385 terawatt-years. Human civilization consumes at least 12.3 terawatts per year of energy.**** Now imagine our future Age of Sail 2.0 civilization. We might conservatively estimate that this society would require at least 100 times as much energy, so call it 1,230 terawatts per year. That means all the proven fossil fuel reserves on Earth in 2015 could only power this civilization for a little over 1 year. Even if we discover fossil fuels on other planets, successfully harvest the methane of Venus and Jupiter at scale, and dramatically improve extraction technologies to access more fossil fuels on Earth, it wouldn’t be nearly enough.
Fossil fuels provide a literal and figurative rocket boost to humankind (photo)
Though the precise numbers are speculative, the implications are not:?fossil fuels are not practical for civilizations beyond Type I. That said, they may well be critical if a civilization wishes to reach the stars in the first place. We might think of fossil fuels as a sort of rocket booster for civilization—they provide a crucial accelerant in the early millenia of an intelligent species, but their heavy, finite, and rare nature means they must ultimately be discarded in favor of something better.
The gassy elephant in the room
It might be surprising that I haven’t mentioned pollution or climate change yet. Those downsides are at the center of most modern debates over fossil fuels, along with the upsides of job creation and energy independence. I’ve so far ignored them to focus on the ultra-long-term prospects for fossil fuel use.?But climate impacts would matter to a spacefaring civilization as well, and there’s value in looking at the issue from their perspective.
Such a civilization might think of pollution—particularly the greenhouse gas emissions that cause climate change—as a fourth downside of fossil fuels that interacts with the other three. This downside doesn’t really kick in until a civilization has burned fossil fuels in sufficient quantities to start affecting the climate system of a planet, but once the effect starts, it can be difficult to stop.
It’s important to remember that the greenhouse effect itself is not automatically a downside. The heat trapped by Earth’s atmosphere is a critical force for keeping conditions here suitable for life. If we wish to terraform other planets, artificially inducing the greenhouse effect may be an excellent way to use natural forces to produce an environment more to our liking. To a spacefaring society, the greenhouse effect would not be thought of as a universal bad or good, nor as a political matter. It would simply be a fact of physics that can be manipulated to human benefit or detriment, like electromagnetism or Bernoulli’s Principle.
A spacefaring civilization might think of planets in terms of carrying capacity: the natural ability of a system to support a certain amount of human or animal activity.?Just like forests have a carrying capacity for deer and oceans have a carrying capacity for fish, geo-atmospheric systems have a carrying capacity for the burning of fossil fuels. A certain amount will be relatively harmless to the atmosphere, and even beneficial if the goal is to terraform a cold planet. But once combustion of fossil fuels on a given planet reaches a certain point, it begins to have detrimental effect on key planetary systems. Temperature begins to increase unpredictably. If present, flora and fauna begin to die off as they struggle to adapt. Dynamic systems like winds, ocean currents, and thermohaline circulation are altered. Ice, whether made of water or something else, begins to melt. Oceans rise and their chemical composition changes. In general, natural equilibria that developed over billions of years are replaced by chaotic fluctuations. On a planet where humans are isolated from these gyrations (say, a research colony supplied by off-world means, or an orbiting space station), the effects on human well being might be minimal. But to the extent that the population relies on planetary systems for food, water, energy, propulsion, and habitation, the effects could be catastrophic.
Critical systems like monsoons are altered by the greenhouse effect (photo)
So how would a multi-planetary society (say, a nascent Type III civilization) think about the state of the greenhouse effect on Earth today??Let’s imagine an operator in some galactic control room, responsible for the maintenance of equilibrium on thousands Dyson spheres in this particular arm of the Milky Way, as well as the monitoring of uncontacted Type 0-1 civilizations in the region. It’s safe to say she would have some serious klaxons going off. Response teams would arrive on Earth to find a planet ripe with potential, having been catapulted into rapid development thanks to the miracle of fossil fuels, but now facing systemic climate crisis due to unintended consequences. Perhaps first contact would come in the form of an interstellar bailout package, or the gift of a prototype fusion reactor with instructions to check back in a century or two.
In the real world, we cannot rely on a cosmic knight in shining armor.?If we hope to leave the cradle of Earth, it must not be at the expense of key planetary systems that we still rely on for food, water, and habitation. Humanity’s ancient legends got it exactly right:?just like Pandora’s box or Prometheus’ gift of fire, fossil fuels come with both enormous benefit and terrifying cost if abused.
Back to 2017
The idea that fossil fuels must give way to other forms of energy will be obvious to some. And others will say that it's the precise timing and execution of the transition that matters to the modern debate, not the general principles that guide it. Both of those points are valid. But I think it's important to remember how the arc of the energy universe bends as we make policy, build businesses, and live our lives. And frankly, I think we could do with a little more imagination.
Despite massive growth in wind, solar, efficiency, and other technologies over the decades, the uncertain policy environment can make it seem like long-term progress remains on a knife’s edge. I beg to differ. While we may see year-to-year and even decade-to-decade variability in clean energy growth, the end result of a nearly 100% clean energy economy is inevitable.
Our task as a society is to speed the transition and minimize the threat posed by fossil fuels in the short term. It is only then that we can take our place among the stars.
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*?I can already hear the rumblings of physics enthusiasts itching to point out that the universe is much messier than I imply here. They might point out dark energy, or radiation given off by black holes, or wacky energy-generating quantum phenomena that fall outside of this rule, and they would be right to do so. But my main point here is that stars are by far the dominant source of measurable, predictable, usable energy in the known universe at this time.
** There’s a strong argument to be made that the Anthropic Principle applies here:?specifically, that we didn’t happen to evolve on a planet with fossil fuels, but that the ancient processes that created fossil fuels (i.e. the proliferation and death of a large number of animal and plant species on a geologically active planet) also helped give rise to intelligent life. In other words, planets with more fossil fuels are more likely to harbor intelligent life, so the odds were biased in our favor.
*** It’s worth noting that fuel sources that occur as fossil fuels on earth may occur on other planets even if they never harbored life. For example, many planets in our solar system have methane (i.e. natural gas) in their atmospheres, and some of them (like Venus) have it in concentrated amounts. It’s possible that human colonies could harvest these fuels for local use. So the argument here isn’t that all chemicals found in fossil fuels are universally useless for a spacefaring civilization, but that terrestrial fossil fuels as we use and transport them today would be impractical for colonization.
**** These are very rough numbers from British Petroleum and the International Energy Agency, and they come laden with caveats. But they are close enough to prove the point of this thought exercise.
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Joe Indvik is a clean energy entrepreneur, and Richard Feynman is his spirit animal. He is Founder & Principal of Rock Creek Consulting, a consultancy specializing in clean energy finance, sustainability, and business operations. Prior to that, he co-founded SparkFund, a start-up that is transforming how energy efficiency is financed.