Population blind spot

The kind folks at New Scientist magazine published another of my letters this week. This one's all about global population and is a response to an article in the magazine discussing whether we, as a species, could have avoided wrecking our environment by advancing technologically without fossil fuels:

Examining the possibility of a world without fossil fuels, Michael Le Page comes to the conclusion that global warming may be an inevitable result of any industrialised civilisation, as fossil fuels are an unavoidable phase of that development (18th October pg34). He also reports that this might explain the apparent absence of extraterrestrial civilisations despite the high probability that they exist, as each planet offers once chance at transitioning from reliance on finite fossil fuels to renewable energy sources.Perhaps it would be useful to consider a sentient race that could control its population? If our global population had stabilised at a healthy 7 million, rather than 7 billion or more, it's perfectly feasible that we could have passed right through our fossil fuel phase without wrecking our planet's environment.


The editor writes: We will never know for sure. But it is likely that a critical mass of people as well as energy is needed to reach something we would recognise as an industrialised civilisation.


It's an interesting response from the New Scientist editor. How many people
would be needed on this planet for us to continue to develop successfully as a technological species? From a genetic perspective, a species' minimum viable population (or MVP) is in the thousands, so a human population of a million or more is definitely genetically healthy. Genetics aside, what population is needed for technological development? What global population would be required to keep us advancing technologically to the point where we did developed a purely renewable technology society?

Well,
how about the entire Roman Empire?

Roman_Empire_Trajan_117AD

The map above (courtesy of the Wikipedia page) shows the extent of the Roman Empire in around 100 AD. It was big. Surely if our global population was the same as the population of the entire Roman Empire, we'd be able to keep going technologically? Around the time of Christ, daily life in Roman Empire wasn't significantly different from today. They had water supplies, sewage systems, household heating, international trade, docks, cranes, pottery and metalwork and a quality road network. They had developed mathematics, researched complex astronomy and created steam-power prototypes. If the Roman Empire was the only civilisation in the world and its population had stabilised at that point and it had been given enough time, surely it would have been capable of advancing past us? It is true that a lot of technological development in Europe was thanks to developments outside Europe, particularly from the Arab world but the Arab world gained many of their technological developments from Egypt and Greece, which were both part the Roman Empire. For a scientist trying to decide on a critical mass of people required to develop into a modern industrial civilisation, the population of the Roman Empire would seem an adequate amount.

Here's the rub. The population of the Roman Empire, east and west together, in 400 AD, was
70 million people. The entire population of the world at the time of Christ was about 170 million people. Our current global population is a hundred times larger than the population of the entire Roman Empire.

It's very strange that the subject of population is very rarely mentioned when people talk about climate change. It's almost a blind spot and yet population is the elephant in the room. For example, for every extra person in Britain, we need to spend £140,000
more on infrastructure; roads, houses, hospitals etc. Extra people are a big burden. For anyone interested in learning more about the effects of population increase, I recommend visiting the population matters website. Population Matters is a charity that works to educate and inform people about the effect of population on our planet and ourselves. The '£140,000' fact comes from a recent study they conducted into the effects of population growth.

There's a dark final point to the matter of a sustainable global population. It would seem that 70 million people (or 1% of our current population) is a believable global population for survival and development. We've grown fifty times larger in the last two-thousand years and we're still growing, but all the evidence points to climate change putting us back
down to that figure in the next five hundred years if we don't do it ourselves. That reduction will be brutal and ugly if we don't find a way to do it ourselves humanely. The choice is ours.