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What is Sustainability?

Defining a critical concept and its implications.

It's unfortunate that the term "sustainability" connotes liberal environmentalists driving hybrids, drinking soy milk, growing wheatgrass, and living in hippie communes with composting toilets. There are other terms for that, but sustainability is something different. We're going to define it and explore its implications without the baggage and ideological squabbling.

Sustainability is about long-term viability.

It's not necessarily some green organic eco-utopian zero-waste regenerative ideal. It's about being everlasting, enduring, future-proof, continuous, and indefinitely viable.

Two dictionary definitions are as follows:

sustainable [ suh-stey-nuh-buhl ]

  • pertaining to a system that maintains its own viability by using techniques that allow for continual reuse

  • capable of being maintained at a steady level without exhausting natural resources or causing severe ecological damage

Everything we need for our survival and flourishing depends, either directly or indirectly, on our natural environment. Pursuing sustainability means creating and maintaining the conditions under which humans and nature can exist in productive harmony to support present and future generations.

Sustainability describes a condition in which human civilization can continue to exist indefinitely, in harmony with the natural world, without depleting resources or causing environmental degradation. It is the long-term outcome that sustainable development seeks to achieve.

It is, or it isn't

Sustainability is binary. It either is, or it isn't, although rates of unsustainability can vary. To determine if our civilization, industry, process, practice, company, or habit is sustainable, we must ask: " If nothing changes, can this continue indefinitely?"

If a person consumes 500 kcal more (or less) than they burn each day, that's not sustainable.

If a company's expenses exceed their revenues, it's not sustainable.

If a farm removes more nutrients from the soil than it returns each year, it's not sustainable.

A process can change its sustainability status over time. Businesses often survive by living off seed capital or outside investments for a period of years after founding. They use these initial cash infusions to pay expenses while they work through product design and honing their business models before they have a product ready to sell to generate revenue. At this stage, they are unsustainable. Once these businesses start selling products to customers, their revenue can exceed their expenses. If they regularly generate a profit in this way, the business can shift to being financially sustainable.

The Economy and the Environment

If we ignore the environment and ecosystems and just focus on economic activity, for argument's sake, the economy still must be sustainable in order to maintain living standards and growth. The net amount and quality of resources flowing into an economy must not decline if it's to endure and grow. There are material inputs like food, water, copper, phosphorus, nitrogen, oxygen, crude oil, wood, steel, etc, and there are outputs such as waste plastic, waste food, wastewater, waste materials, waste heat, and waste gasses like carbon dioxide and nitrogen oxides.

Those material inputs come from the environment, though, just as the material outputs go into the environment. So we can't separate the economy from the environment since the economy is underpinned by materials and energy sourced from the environment.

If economic activity hinders the environment's ability to supply material and energy resources, either through over-extraction or disturbance from waste streams, the economy will suffer. All else equal, costs will rise, or living standards will fall.

We all know that the prices of goods fluctuate with supply and demand. If demand for a natural resource remains constant as its supply declines, its price will rise. Now technically, we don't pay for the natural resource itself, we pay for its cost of extraction. Innovations in extraction technologies can hide the fact that a resource is depleting becuase the price of the resource doesn't go up. Horizontal drilling and fracking is an obvious example of this.

We don't pay nature for her resources – at least not upfront. We pay the human labor cost, operational expenses, and amortized capital expenses associated with extracting those resources.

The Big Picture

If we don't collectively transition to sustainable uses of energy and resources, civilization will cease to exist. Expenses can only exceed revenue for so long.

Just as a business can change from being unsustainable to sustainable, so too can our civilization, although the process is much more complex. Our current civilization, while providing us with the best living standards and the coolest technology in history, is not sustainable. Since the Industrial Revolution, our economy has been underpinned by cheap, abundant energy in the form of fossil hydrocarbons. It's also supported by natural resources such as metals, fresh water, and arable land. There isn't room to go into detail on all of humanity's unsustainable practices here, but suffice it to say that if we don't collectively transition to sustainable uses of energy and resources, civilization will cease to exist. Expenses can only exceed revenue for so long.

The stakes are pretty darn high, no?

Finite vs Renewable Resources

Finite resources are limited and deplete with use, such as fossil fuels, freshwater aquifers, and minerals, while renewable resources, like solar energy, naturally replenish and can sustainably support long-term use. The main distinction is their long-term availability and environmental impact.

It is important to consider usage rates compared to renewal rates. While coal can technically be renewed, it takes tens of millions of years. The massive discrepancy between the renewal and extraction rates is what makes coal a finite resource. Even with resources that are considered renewable, such as wood, the rate of wood consumption must not exceed its rate of growth if wood use is to be sustainable.

The Central Challenge

We don't know how long civilization's current practices will last, but we know we're spending our seed capital. Rates of finite resource use are high, and usage rates of some renewable resources are higher than nature's ability to renew them. We either continue to run an extractive economy based on non-renewable resources until we face resource depletion, rising costs of goods, lower standards of living, environmental degradation, and the civil unrest that comes with it, or we transition to a sustainable civilization.


In order for civilization to be sustainable, resource renewal rates must exceed the rates at which we extract resources from the environment.

Our rate of resource extraction is proportional to [resource use per person] and [number of people]. We can break it down further and say resource use per person is proportional to [living standard per person] and [resource intensity per living standard].

To put it all together:

[resource extraction rate] is proportional to [living standard per person] and [resource intensity per living standard] and [number of people]

As living standards increase across the world, resource extraction rates do too. And as the population of the world increases, so do resource extraction rates.

Steps for Progress

There are steps we can take to move towards sustainability. One thing we can do is simply want less. If we reduce our individual rates of consumption, overall resource extraction rates will decline. Admittedly, this goes against human nature and the hedonic ratchet – where we are inclined to pursue more.

The other big opportunity for moving towards sustainability lies in decreasing resource intensity per living standard. If we can reuse or recyle the materials we use in our lives such that they don't require more materials to be extracted from the environment, overall extraction rates can decline. This is the idea behind "circularity." Complete circularity is not possible due to exergy destruction and the Second Law of Thermodynamics, but it can significantly offset the requirement for new material extraction by reusing what has already been extracted.

To fulfill our massive energy needs, renewable sources such as solar combined with storage methods can be utilized for many applications. Similar opportunities for moving towards sustainability exist in food production, forestry, industry, water management, and the countless ways we use energy and materials.


Sustainability is about maintaining the long-term viability of our civilization, not just for the sake of the human species but also for the health and vitality of all of Earth’s ecosystems, ensuring that our planet remains livable and productive for current and future generations. It encompasses a wide range of practices and principles that guide how individuals, communities, and economies operate in relation to the environment and each other so that we can keep this great thing we've got going and going.

Questions for you:

  • Can you think of any arguments against sustainability? What are they? (Party like it's 1999, I'll be dead, I don't care, not my problem, etc)

  • Are you optimistic about achieving a sustainable civilization? Why or why not?

  • Are you one of the few innovators working towards sustainability? If so, comment and drop me a message. I'd love to hear from you.

Book Resources for Understanding Sustainability:


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