In 1800 the world’s population was around 1 billion people. Since then it has increased more than sevenfold to reach over 7.5 billion in 2017 and is forecasted to top 10 billion by 2050.
Will population growth inevitably continue or will it level off over the long term? Should we try to reduce or stop this growth? I’ll try to map out the statistics here so we can get a view of how the earth looks now.
Simply put, the world’s population is increasing because the number of births outnumbers deaths by three to one.
A surplus of births first occurred two centuries ago in Europe and North America, when mortality started to decline. This marked the beginning of what scientists now call the demographic transition. This transition subsequently spread to the rest of the planet as social and economic progress, combined with advances in hygiene and medicine, began to reduce mortality rates. With people having longer lives than before due to the technical and medical advances, the ratio to the number of people dying per annum differs largely. The resources instead of being shared by a consistent ratio of people are now at stake because every year there are more and more people who need to utilize the sources present such as water, land, plants, animals etc.
Most contemporary estimates for the carrying capacity of the Earth under existing conditions are between 4 billion and 16 billion. Depending on which estimate is used, human overpopulation may or may not have already occurred.
The annual population growth rate actually peaked half a century ago at more than 2% and has fallen by half since then, to 1.1% in 2017. This trend should continue in coming decades because fertility is decreasing at a global level, from 5 children per woman in 1950 to 2.5 today. In 2017, the regions where fertility remains high (above 3 children per woman) include most countries of intertropical Africa and an area stretching from Afghanistan to northern India and Pakistan. These are the regions that will drive future world population growth.
These figures are projections, and no one can exactly predict what the future will bring. That said, demographic projections are quite reliable for forecasting population size over the next 10, 20 or 30 years. Most of the people who will be alive in 2050 have already been born, their number is known and we can estimate quite accurately the proportion among those currently alive who will die. Likewise, the women who will bear children over the next 20 years are already alive today and can be counted. By estimating their potential fertility, we can determine the number of future births with relative accuracy.
It would be unrealistic to imagine that population trends can be modified over the short term. Depopulation is not an option. Indeed, how could it possibly be achieved? Through increased mortality? No one hopes for that. Through mass emigration to Mars? Unrealistic. Through a drastic and durable decrease in fertility to below replacement level (2.1 children)? This is already taking place in many parts of the world, as couples decide to have fewer children so as to give them the best chances for a long and fulfilling life – an example of this is China who has been taking up on this initiative for years now as they were successfully able to recognize the rate of overpopulation in their country.
But for reasons of demographic inertia, this does not result in an immediate population decline. Even if world fertility were just 1.6 children per women, as is the case in Europe and China, the population would continue to increase for several more decades; there are still large numbers of adults of childbearing age who were born when fertility was still high, so the number of births also remains high. The proportion of old and very old people is very small, on the other hand, so deaths are far less numerous. The difference between ratios has increased so drastically that it’s predicted overpopulation will be inevitable.
Of course, humans must start thinking about the need for long-term equilibrium today – it is the next few decades that are of most urgent concern.
The world population will inevitably increase by 2 to 3 billion between now and 2050 because of demographic inertia that no one can prevent. Nonetheless, we have the power to change yet now our way of living – and there is an urgent need to do so – by ensuring greater respect for the environment and more efficient use of natural resources. Avoiding the use of water for car washes, turning off water taps to avoid leakage, eradicating the use of plastic bottles to prevent mass plastic production and also putting up well filtrated water coolers around towns and cities is a very essential alternative so people don’t buy four water-bottles a day, instead they just refill their flasks/thermoses.
Reducing the use of plastic straws, bags, bottles are also very essential as plastic does not decompose – instead makes the land useless for any or all agrarian activities. There’s a need to cut down on synthetic fiber-based products and adopt the usage of paper bags or any bio-degradable products.
All in all, the long-term survival of humankind depends more on its choice of a lifestyle than on its population size.