- Once we were few, now we are many….
- In ~8000 BC, about the time sheep and pigs were domesticated, the world’s population was probably around 5 million. That’s similar to the modern population of Norway, or around 1 person per 30km squared of land area.
- At the start of the iron age, at around 1000BC, the global population is estimated to have been
~50 million, approximately the population of South Africa.
- In 0AD the population is estimated at around 200 million, similar to the modern population of Brazil.
- The world’s population grew from this to 1bn in 1800, to 1.65bn in 1900, to ~ 6bn in 2000.
- In just 12 years of the 21st century the world’s population grew by another 1bn, to just over 7bn in 2012.
And Then There was Many
The Population Doubled in the 40 Years from 1950 to 1990
- In 2007, world population growth was calculated as 1.19%, down from 2.2% in 1963. The growth rate for developed regions was 0.4%, whilst for developing regions it was 2.2%.
- In terms of doubling time (the time required to double to current population, given an exponential growth rate), those growth percentage numbers mean that world population will double in 59 years at a growth rate of 1.19%, the developed nations population will double in 175 years at a growth rate of 0.4%, and developing nations population will double in 32 years at a growth rate of 2.2%.
- Of course, growth rates change, in fact they will have to.
- At a population growth rate of 1.3% per year the world population would grow to a density of one person per square meter of land in just 780 years and beyond that the mass of people would equal the mass of the earth in just twenty four hundred years.
- Expontentials are like that, they just keep on growing...
- This clearly isn’t going to happen. However, even if you drop the growth rate of global population to the current developed nation rate of ~0.4% you still end up with 1 human per square meter of land in 2500 years, which is about the same amount of time from now as we are from when Cyrus, King of Persia allowed Jews from Babylon to return to Jerusalem.
- At the moment the figures show that there are about 80 million additional people per year. That’s roughly the population of Germany. It is likely that the world will pass 8bn in just 10 years.
- For us to have more future than we have recorded past, the growth rates will eventually not just slow, but stop… Things will change.
- Today, just over 40% of the world’s population is under 25 years old. The percentage rises to just above 60% for developing countries.
- Half the world now lives in cities. The population centers with the highest density are in South and South East Asia, particularly China and India.
The Asian Century
- For a prosperous way of life, all of these people need energy.
- 10% of the world population (OECD) uses 56% of the world’s fossil fuels (2009)
- 90% of the world’s population has a small but rapidly growing appetite for energy (and prosperity). In 2010 China passed the US as the number 1 energy consumer, yet today the average American uses four times as much energy as the average Chinese person.
China passes US as energy consumer