Currently, towards the end of 2014, the net increase of the global population is estimated to be 225,000 persons per day.
In one month the increase is 6,750,000 people, in a quarter it is 20,250,000 which is nearly the same as the population of Sao Paulo or Mexico City (including their metropolitan area), and over 80 million in one year which is very similar to the total population of Germany at the end of 2013.
One way to think about the pressure on the global environment by this increase in headcount is to imagine the space required to support their lives. Cities are not suitable places to produce food for their inhabitants. According to data from the World Bank the arable land per person in 2012 was 0.20 ha. 50 years earlier, in 1961 it was almost twice as much, 0.37 ha, but due to the revolution in agricultural technologies and fertilizers and antibiotics now much less space is required to support food supplies for more people.
The size of arable land required to provide food for 20 million people is about 40,500 km2 ? increase per quarter, 162,000 km2 increase per annum.
The size of a town itself, accommodating 20 million people, can be estimated to be 8,000 ? 10,000 km2. For the sake of simplicity, the required land for the people and for food production can be as much as 50,000 km2 quarterly.
It can be an interesting exercise to look at the map, Google Earth or Google Map for example, to find an unoccupied area of 50,000 km2 for the quarterly increase of the population to settle and produce food, bearing in mind that at the current technological level: surface of oceans, deserts, mountain areas and the poles are not suitable for this purpose ? yet.
This exercise must be repeated for each and every quarter. It might seem to be difficult task, but it happens ? gradually and continuously. Settlements keep growing, taking space from their surrounding natural areas, destroying pristine habitats and their inhabitants, and chasing out creatures capable of escape.
Considering this yearly increase the land requirement is as large as Nebraska State (USA) or twice that of Cuba.
It is worth noting that the following factors ? even if incomplete ? have been ignored:
Land requirements for
– dumping waste,
– generating energy,
– taking water supplies for irrigation, drinking and for household purposes.