Sustainability is the buzzword of the day. Everyone wants sustainability. But somehow, everyone seems to miss the point of sustainability. Have you heard a policy maker talk about “sustainable growth”? That’s utter nonsense. Anyone putting a bit of thought into the matter will realize that growth cannot be sustainable indefinitely. After all, there is only a finite set of resources available to fuel it. Leaving aside systemic biases toward perpetual growth, however, let’s muse about what a sustainable settlement on any planet would need to look like.
First, let me set the stage by describing the preconditions for survival. First, sufficient food and clean water must be available to the settlers. Second, sufficient shelter must be provided to protect the settlers from the harshness of the environment. That’s it. That is all that is required for survival. Let us call that a “subsistence level” settlement.
Presumably, the settlers will desire some level of entertainment. and they will have wants beyond bare subsistence. They may be driven by curiosity to research science or by creativity to tell stories. They will also desire comfort beyond the bare necessities. Such things as health care when disease strikes would fall into that category. Any activity beyond bare subsistence will require diverting resources to it and, thus, reduces the total resources available for subsistence. Let’s call a settlement that has excellent health care, comfort, culture, and general happiness an “advanced level” settlement.
Let’s also take a leaf from biology and throw in the concept of “carrying capacity”. That is the total population or a species that can be sustained by an environment. As long as prevailing conditions remain unchanged, the carrying capacity will remain unchanged. Various factors affect carrying capacity. For instance, the ability of the environment to produce sufficient food for the population has a direct and limiting impact. Additionally, the rate at which the environment can absorb the population’s waste has a direct limiting impact. Waste produced in excess of the absorption rate causes net damage to the environment and reduces the carrying capacity. Extraction of food beyond the environment’s ability to produce it also causes damage and reduces the carrying capacity. Replace “food” with any resource in the preceding text and it remains valid for that resource.
Clearly, to maintain a population at or near the carrying capacity of an environment requires carefully regulating both resource draw and waste deposition. It also requires limiting population growth once the carrying capacity is reached, though resource draw limits should ensure that indirectly. In a human society, more direct population control methods can be achieved.
The barest level of subsistence is simply living off the land. This is a minimal energy approach to survival and is sustainable assuming the land can support a sufficient breeding population. This is, however, important, because it is also the ultimate fallback in the event that more advanced settlements prove unsustainable. It can be argued that minimal energy subsistence is the only long term sustainable practice as long as the population remains stable at or below the ultimate carrying capacity.
Let’s now consider a society like the “western” societies of Earth. These are energy hungry settlements that consume massive quantities of resources. It is clear to anyone who cares to look that the current practices of western societies on Earth are unsustainable. Can they be made sustainable while maintaining something approaching the current standard of living (or even exceeding it)? Is it possible to have an advanced level settlement that is also sustainable?
First, let us consider population. In the current Earth situation, the population is growing. With seven billion people on the planet, it is clear that the population is higher than necessary to provide a sufficient breeding population. The first thing that must happen to make an advanced settlement sustainable is for the population to stop growing. Sustainability becomes easier as the population decreases toward the minimum breeding population.
Assuming the population problem can be solved, there is still the problem of resource consumption. Energy consumption is well beyond the reasonable ability of the Earth and Sun to provide sustainably. We are burning through fossil fuels at a rate so far beyond their potential replacement rate that they might as well be viewed as non-renewable. (Clearly they were created in the first place so they can, theoretically, be created again, but it’s unlikely to be feasible.) It is clear that energy consumption per capita must be reduced.
One of the major components of energy use is in transportation. Where a subsistence level settlement will tend to use low energy transport mechanisms such as walking or, perhaps beasts of burden, the advanced settlement tends to rely on vehicles that produce hard to sink wastes and require large quantities of difficult to produce fuel. The need for transportation continues to increase as population increases and settlements sprawl over many miles. Resources must be diverted into maintaining roads, vehicles, and fuel production. All of this can be eliminated or greatly reduced by a single simple expedient: increased density. Rather than having sprawling suburban areas, move the people into much closer proximity and limit the distance they must travel from their homes to their work or supermarket.
Of course, limiting sprawl only affects the transportation cost for people. As long as people continue to consume random stuff at an alarming rate, there is another massive energy and resource sink: luxury goods. Luxury goods are those things that are not required for survival. That includes such things as the device you are reading this on, fiction, sculptures, toys, televisions, and so on. Many of these items use a crazy amount of energy and require a crazy amount of energy and other resource input to produce. Additionally, they are difficult to dispose of when no longer wanted, needed, or when they are no longer functional. These goods also need to be produced somewhere, transported to the people who want them, and then transported away again when they are disposed of. Production and consumption of unnecessary stuff is a massive contributor to resource consumption and waste generation. This can, obviously, be limited by limiting the consumption of such goods. How to do this has been culturally problematic. This can also be mitigated by processing the waste to recover resources that would otherwise need to be obtained from the environment. However, recycling also consumes energy and is not always easier on the environment than further exploitation. It may be necessary as resources dwindle, however.
Even if energy consumption can be dramatically reduced, there still needs to be a means of generating it in useful quantities which does not rely on non-renewable resources. As demand drops, clearly this problem becomes easier to solve. Solar thermal energy, tidal generation, hydroelectric generation, windmills, and so on, are all viable. For some applications, burning portable fuels in internal or external combustion engines will remain the most viable. As long as the waste heat and other emissions from such sources can be absorbed by the environment without damage, such technology is sustainable. However, demand on such generation must be kept as low as possible through means such as population control and limiting consumption.
Let us now assume that humanity manages to transition to a sustainable model before the Earth’s human carrying capacity falls to dangerously low levels. What will that human civilization look like?
First, I expect a number of very dense cities situated in strategic locations. These cities will have access to sustainable energy generation and will also be constructed in such a way that they minimize the need for energy to moderate climate within. Surrounding these dense population centres will be vast open spaces mostly allowed to go wild. Long distance travel will either be expensive, thus limiting demand, or will take a long time as people employ their own legs to make the trips, at an immense opportunity cost. Within cities, public transportation and walking will be the dominant mode of transport with only those who actually require vehicles for their work actually using them on a regular basis.
The most significant change from current societies will be cultural. The need to have one’s own of everything will be greatly diminished. The need for instant communication will have passed, thus removing the need for every person to carry one or five personal communication and/or computing devices. Shared terminals will be used for the vast majority of computer work for most people will not require full time access to such resources. Data storage will be in massive purpose built facilities designed into cities in such a way that their waste heat can be used for productive purposes and storage will use energy efficient technologies, even at the expense of the absolute fastest performance. The vast library of information will be stored in offline modes which can be accessed on demand, thus significantly reducing the energy footprint of data storage.
The intense competitive drive of western culture will be replaced with a more laid back attitude. The need to “keep up with the Joneses” or to “get ahead at any cost” will be greatly reduced. Food production will be shared utility just like water is in most cities. Every citizen will be guaranteed basic subsistence with food being provided based on regular medical assessments. Random luxury goods will generally be shared and production rationed based on resource and disposal capabilities.
While traditional agriculture will likely continue with improving technology and methods, by far the largest part of the subsistence food production will come from hydroponic and similar methods in the cities. To the extent possible, organic wastes will be recycled in food production and other wastes will be minimized and recycled to the extent possible. Any substance that cannot be recycled easily will require careful regulation. The vast majority of products in use will be trivially biodegradable and many products that use plastic and metal today will be constructed using plant fibres and other more recyclable materials.
I could go on at length and in great depth about what such a world might look like. However, your own imagination is likely also up to the task.
I do not claim that such a future world would be an egalitarian utopia or anything of the sort. There will be warts. Population controls tend to suggest eugenics, for instance, a subject that tends to polarize people. The point of it is that it be sustainable, warts and all, for no matter how enlightened a society is, if it is not sustainable, it is hardly worth considering as a future goal.