Tag: population

A Home for Everyone

Posted on by Mark

Sweet dreams are made with homes. Imagine your own space where you can live as you want, listen to your own music and make your own meals. All this without having others to provide a running commentary on your choices and actions. Making things our own turns houses into homes.

Understandably, houses come at a cost. Houses also come in a variety of sizes. Using reasonable metrics for these, and aligning them to typically energy rates, we can estimate an equivalent energy cost for building a house. For a smaller house with a less expensive energy cost, a new build is the equivalent of about 8.6×10^12 Joules. If we assume that all 8 billion people live in groups of 4, then we would need 3.9×10^22Joules to build a house for each group’s dreams.

Is this a lot of energy? The energy cost to build a house for each group is over 100 times humanity’s current annual primary energy consumption. If we set the annual house maintenance cost to the typical 1%, then the energy to maintain these homes becomes equivalent to our annual energy consumption. Further, we would need to allocate even more energy for rebuilding houses as they typically last for only 100 years. And, our population continues to grow. How will the Earth satisfy everyone’s dream for a home?
Bird song

Energy to Survive

Posted on by Mark

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?
Lichen

Peak Population

Posted on by Mark

We’ve all seen the curve showing human population growth over time. Some suggest it looks like a hockey stick. Pundits say the population will exceed 8 billion by the end of this year. But they say also that we are approaching peak population. With this, the population will peak near about 10billion people some time later this century and decline. This population decline may be the first in over 10,000 years.

I don’t expect to be around to see this decline, but it is relatively soon. In fewer than 80 years or within the lifetime of a human in developed countries, this decline will occur.

What does this decline say about world economics? Perhaps with the shrinking population, we will have less need to add infrastructure. Though perhaps there will be a greater need to maintain existing infrastructure. And, with less emphasis on production, then there will be a greater emphasis on the service economy. In any case, we can expect and probably demand a change in the world economics of the future.

As 80 years is not that far away, what type of Earth do you plan for your children and grandchildren? Or, what will remain of Earth for them to enjoy?
Ponder

Future Population

Posted on by Mark

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

Density

Posted on by Mark

Will they fit? How many can you put into one space? These are questions of density. Sometimes the answer is easy to measure such as with determining the number of glass marbles that can fit within a box. Or, we can predict population densities over time with the Lotka Volterra predator-prey model. In all density calculations, it is a defined space that is key to the calculation.

Let’s set the space as the land surface of Earth and the question is, “How many people will fit?” For the record, some believe that at one time there were less than a hundred thousand hominin living on the surface. These easily fit and the density barely registers. Yet we predict the population this century to crest at over 10 billion humans. The resulting density is 83 people per square kilometre. It rises to 117 people per square kilometre when we locate people only on viable land cover, i.e. excluding deserts and such. This will be the average global density.

For comparison, at the end of the last glacial period about 12,000 years ago when humans lived as primitive hunter-gatherers, the estimated population was 2 million or about 0.02 people per square kilometre. Contrarily, in the city of Manila today, there’s a local density of 46,178 people per square kilometre. This increased density speaks to our prolificacy.

Density is important as it relates to the amount of resources humans consume. For instance, to maintain current density, we use a third of all Earth’s land surface for agriculture so as to produce food. What do you expect of the future as the human population continues to increase while the land surface remains constant? How can we use local density values to predict sustainability and future survival?