We would be more than 7.77 billion human beings on Earth and two billion more in 2050. What is the impact of overcrowding on the environment and global resources?
Today, we are more than 7.77 billion human beings on Earth (last revision of the United Nations, in its report of March 2020). According to the latest projections, we will be 9.5 billion by 2050. We can explain these forecasts by the demographic explosion in emerging countries and the lengthening of life in developed countries.
Global overpopulation and water supplies
Water is the most precious resource on Earth: global overpopulation could lead to generalized conflicts linked to the blue gold. Clashes already exist, since water is one of the main causes of tensions in the Middle East. A global water conflict would therefore have dire consequences. Currently, 80 countries lack water and one in five people does not have access to clean water. There are solutions to overcome this shortage, such as the desalination of seawater, which is still costly.
How much fresh water is there in the world?
Covering about three-quarters of the Earth’s surface, water a priori is not lacking on our planet. Unfortunately most of this water is salty and is not directly usable by humans. What about fresh water?
Recall that we call fresh water – as opposed to sea water – water with low salinity and which is therefore likely to be fit for consumption by humans and animals. Fresh water is the water of rivers, lakes, rains, etc.
The total volume of water on Earth is estimated at around 1.4 trillion billion cubic meters. A relatively stable volume over time.
What is the percentage of fresh water?
On Earth, 97.5% of the water is salty and contained in the oceans. Only 2.5% is fresh water, or approximately 35.2 million billion cubic meters. On this amount of water:
- 68.7% are found in glaciers
- 30.1% in the groundwater
- 0.8% in permafrost
- 0.4% at the surface and in the atmosphere
In the end, less than 1% of the water on Earth is fresh, liquid water.
Lake Baikal, with its 23,000 billion cubic meters of water, constitutes the largest reservoir of liquid fresh water on the surface of the planet. It is classified as World Heritage of Humanity for the richness of the fauna it shelters.
A large sphere of 1,400 km in diameter would concentrate all of the earth’s water (salt and fresh). A smaller sphere of 272.8 km in diameter would represents the total volume of fresh water. And finally an even smaller sphere of 56.2 km in diameter would concentrates all of the earth’s fresh water available for consumption (lake, river, part of the groundwater).
The uneven distribution of freshwater on Earth
On the surface of the globe, water is distributed very unevenly. The United Nations calls nine countries “power of water”, namely: Brazil, Colombia, Russia, India, Canada, the United States, Indonesia, Congo and China – which account for 60% of the world’s annual water flow. And inequalities can even appear within a country. India for example has desert regions and others that are regularly flooded by the monsoon.
The water war
Climate risks and natural disasters can cause scarcity and or pollution of freshwater. Human activities, domestic, agricultural or industrial discharges, diversion of rivers, etc, can also impact water resources. However, a man cannot survive more than three days without water. And that resource is essential to hygiene.
When the water resource is insufficient to meet human activities and the needs of the environment, that is to say, below 1,700 cubic meters per person per year, we speak of water stress. And a UN report published in 2019 pointed to the close link between water scarcity and mismanagement, and the emergence of tensions and conflicts around the world.
Global overpopulation and food
Currently, the most developed countries have enough resources to feed the entire population of the planet. However not all people on the planet eat their fill, as food is unevenly distributed. One of the consequences of global overpopulation would be to aggravate these inequalities, causing famines.
Global overpopulation and pollution
The pollution of the planet is not directly linked to global overpopulation. The most developed countries are the most polluting, but also those with the lowest birth rates. Hiring dumpster rentals to remove junk is not going to be enough to control pollution in the Western World hooked in overconsumption. Healthier greener habits must be developped.
An American pollutes 91 times more than a Bangladeshi resident. However if the growth of emerging countries continues to rise and if developed countries do not restrict the pollution they generate, then global overpopulation will have a disastrous consequence on the environment of our planet.