Africa was te small
The first modern humans emerged in Africa about 200,000 years ago, and their descendants left the continent 60,000 to 90,000 years ago.
Population experts estimate that there were about 100,000 people at the time.
Population trends have four phases. In stage 1, the birth rate is high, but so is the death rate, so the population grows slowly. When we migrated out of Africa, we were in this phase. At the beginning of the era we were still in phase 1. There were 200 to 300 million people worldwide, and it would take another 1800 years before we reached one billion.
But after that it went fast.
We entered phase 2, with a high birth rate, but a low death rate, partly thanks to new technologies.
In just 100 years, the world’s population doubled, and in 2000 there were 6 billion people. We are now 8 billion and in 14 years even 9 billion.
About four years ago, various regions in the world sounded the alarm about the lack of clean drinking water. Further goes spacious 1 billion people go to bed hungry every night and the same number suffer the consequences of the lack of shelter.
Fortunately, great solutions are on the way: nanofilters for water, vertical farming and 3D printers provide basic needs, while new vaccines arm us for possible pandemics.
Salt water to quench our thirst
The first basic need of every human being is water. We live on a ‘blue planet’, but that is not much use to us, because a liter of seawater contains about 35 grams of salt. Only about 3 percent of the 1.4 billion cubic kilometers of water on earth is fresh water.
Seawater can be desalinated in any of the 20,000 desalination plants in the world, where it is filtered and chemically purified. Half a billion people benefit from approximately 100 million cubic meters of seawater every day.
However, desalination requires a lot of energy and chemicals. Scientists therefore have one new method developed, which can desalinate water using tubes of 1 to 2 nanometers, which consist of the element fluorine.
The researchers have shown that water in these fluorine tubes can be filtered a thousand times faster than in a conventional installation.
However, desalination is only part of the solution to population growth. We also need to change the way we farm.
Agriculture in height
If we want to feed 9 billion mouths, according to estimates double current food production.
However, agriculture takes up a lot of space and is harmful to the environment. Yield is unpredictable due to external influences.
Too much rain leads to flooding, too little to dried out plants. Too much sun will result in blackened crops, but too little sun will prevent them from ripening.
If we opt for so-called vertical farming, in which light and water are controlled electronically,
our food production becomes more predictable and stable.
According to figures from Columbia University vertical farming requires up to 95 percent less water than conventional farming and delivers every square meter 80 percent more food.
Vertical farming can take place near the consumers, so that the harvest does not have to be transported as far. In addition, the food is cleaner and therefore has a longer shelf life, and less food is wasted.
One of the largest vertical farming systems is located in Denmark near Copenhagen. This is where the company grows Nordic Harvest lettuce and herbs on 14 floors. They harvest 15 times a year, which yields a total of about 1000 tons of food.
Houses printed within 24 hours
The world’s population needs houses. About a billion people will face the shortage of shelter in the next two years.
This calls for technology that allows houses to be built quickly – and in a more climate-friendly way than now, because construction is responsible for more than 1,000,000 40 percent of total global CO2emissions.
For this we mainly look at 3D printers.
Many buildings consist of concrete elements that are cast in a factory and transported to a construction site.
However, we can now also 3D print houses on location. For example, a single-family home can be printed within 24 hours.
This leads to less waste of building materials, less transport and less harmful materials.
These can be mixtures of recycled concrete or discarded wood, from which a kind of chipboard is made.
Wood production requires little energy, is good for the indoor climate and wood binds CO2 while it grows.
Scientists disagree about the boundary
The population is not growing at the same rate anywhere. In the western world, we entered phase 3 after World War II. The birth rate fell thanks to contraception, higher wages and migration to the cities.
Developing countries will eventually also reach phase 3 and then phase 4, in which birth and death rates are practically in balance and population growth stagnates.
Before we get there, the increasing number of people living in densely populated places will be threatened by one phenomenon in particular: pandemics.
In an analysis that will be published in 2021 in the scientific journal PNAS was published, the probability of a new pandemic is estimated to be about 1.9 percent per year.
If a virus more contagious and deadly than corona spreads worldwide, it could kill hundreds of millions of people.
Because of corona, we are now developing all kinds of new vaccines, but it takes time to adapt them to new diseases. That is why the pharmaceutical company Moderna is now developing vaccines against diseases that do not yet exist.
The idea is to build a library of different ‘extracts’, which can be quickly developed into vaccines against specific diseases.
If we prepare properly with vaccines, the world population can grow steadily in the coming years.
Scientists’ estimates of how many mouths our planet can feed vary widely. The UN studied estimates of as many as 65 different studies.
33 of these set the limit at 8 billion people. We have already exceeded that. However, some scientists believe that the Earth can feed as many as 1 trillion people.
Anyway, the UN predicts that by 2100 there will be about 12 billion people on earth. Since you started reading this article about 15 minutes ago, 2500 have already been born.
