Energy to Survive

We’ve already noted that we live on a finite world. When people use its resources, regardless of whether renewable, the resources are not available for anything else. Our current use of energy enables both our numbers and our technology to flourish. A growth economy assumes this approach is without end. It assumes we live on an infinite world.

As you can well imagine, eventually the energy supply will not meet the energy demand, as our world is finite. How do we address this? In a market economy, if a product or technology is unsustainable, then it disappears. Will we hold the same principle to life? When the energy supply to support life proves inadequate, then people disappear. Perhaps we let people choose for themselves. They may choose between either technology such as a cellphone or food such as bread. Those who choose badly will disappear and, eventually, energy demand will equal supply.

Should we extend this same logic to all life? Wildlife needs both energy / food and space to flourish. Sometimes numbers explode as for mammals after the Cretaceous-tertiary extinction event. And we see numbers crash as with reindeer on St Matthew Island. Logically, if people consume most of Earth’s energy resources then wildlife numbers will crash. With the continual rise in our energy consumption, are we unknowingly planning a future Earth that will sustain life only for some humans together with their chosen support creatures?


We describe planet Earth as being in the ‘Goldilocks Zone’ for life. What does this mean? It means that Earth’s orbit about the sun is at just the correct distance for life to exist. In particular, Earth’s surface maintains water in a liquid state. If the Earth were colder, the water would be solid, i.e. a snowball Earth. If the Earth were warmer, the water would quickly vaporize, making Earth unsuitable for life. Today, neither of these conditions exists, so life on Earth flourishes.

However, the Earth’s surface is a system that balances heat. Heat comes from the Sun and from the Earth’s core. Heat gets emitted as radiation. If these balance, then the Earth’s temperature remains constant. Obviously, if it doesn’t balance, then the Earth’s surface gets either hotter or cooler. We are now seeing an imbalance as temperatures are increasing.

The Earth’s oceans have heated by 337 zettajoules (3.37×1023 J) since 1955. The Arctic ice and mountain glaciers are melting. Indications are that human actions have caused this change; this imbalance. In corollary, we are changing the temperature of our bowl of porridge. Goldilocks will no longer be content with it. Nor will life flourish with it. Is this our future?
Desert Sky

Future Population

Have you ever wondered how many people could fit on Earth? Likely there’s more now than at any other time in Earth’s history, almost 8 billion. Yet what of the future? The World Bank predicts a peak of about 11 billion sometime this century. Or, there’s talk of a human population crash with the total dropping greatly. Yet, the population might just keep climbing to some, eventual maximum. That is, we don’t yet know how many people could possibly fit.

Let’s say the population remains the same as today. If so, then we certainly know the problems and for the most part the solutions. Such as, we’re on track to addressing climate change. We understand the importance of biodiversity and the value in preserving it. And, we realize that finite fossil fuels need be replaced by renewable energy sources. That is, the Earth might sustain the current population.

However, what of a population that continues to climb? A consequence is increasing pressures on Earth systems as people demand more energy, more food, more resources. That is, instead of solving problems, we’re exacerbating them. Climate change is quicker and greater. People use more land for themselves thus allocating less for biodiversity. And, we need all sources of energy even those not sustainable. This lack of sustainability means that Earth systems fail and eventually fewer people could fit on Earth.

Is there value in setting a maximum to the number of people on Earth? How would you calculate this value? And more important, how would you enforce this value?
Great Bear Lake