As a result of this abundant and relatively low cost source of energy the worlds food yields increase and greater populations can be sustained. Conversely as populations increase, food demand increases, more land use moves to agriculture, more fossil fuels are used to provide fertilizer, pesticides and transport, more mobile phones and games consoles are manufactured and used by the increased population.
In 1980 there were 4.44 billion people and in 2015 there were 7.35 billion people; in 1980 we used approximately 67000 TWh of energy, in 2015 we used approximately 160000 TWh. More people equals more energy. What is a TWh? N.B. The 160,000 TWh number includes biofuels (mostly wood) the graphic above does not, hence the slight difference.
What does 160000 TWh look like? It is very difficult to visualize this amount of energy, so here is a fairly mad example to try to show how much energy this is.
It requires about 0.65kWh to drive a car 1km it is 40,000 km around the earth, so given that some one builds a bridge across the Pacific and the Atlantic and the Americans let you in, you would use 26,000 kWh. Divert via Mexico perhaps if you cannot get into the USA.
So with the full world energy consumption for one year you could wiz round the world 6.2 billion times in your family hatch back, and would probably require 10 billion tyre changes in the process! [160,000,000,000,000 kWh / 26,000 kWh, where 160,000 TWh = 160,000,000,000,000 kWh]
Energy Use per person
In 2015 we used 21700 kWh per person on average in the world, this includes heating, cooling, transport, agriculture, electricity, everything, including burning wood.
160,000,000,000,000 kWh / 7,350,000,000 people = 21700 kWh / person
With the USA using 88000 kWh per person and and average of all the Africa nations 7000 kWh per person. I make no comment here judge for yourself.
So what does the future hold? It is virtually certain barring catastrophe (Hummm Trump is President…) that the world population will hit nearly 10 billion by 2050, given that a 2.9 billion increase in population from 1980 to 2015, created a demand for an extra 93,000 TWh per year is seems reasonable that the demand will grow by a further 90,000 TWh, so we will require 250,000 TWh by 2050. Even if we generate a very optimistic 20% of this with renewable energy or nuclear we will still be burning more fossil fuels than we do today and accelerating climate change. And I would argue that by supplying the demand we will be increasing the population. Conversely if energy supply is limited people will die.
Some Useful Linkshttps://en.wikipedia.org/wiki/World_population