Our Environment: Part 7 – Managing the Human Population

There are numerous websites that show the human population numbers changing “real time” – the last single digit constantly changing – possibly as fast as 4 new humans every second.  How do we slow this down?

As we mentioned in the last article, other creature populations respond by either slowing/stopping reproduction or having members of the population disperse to new territories to reduce the pressure on the resources.  Sometimes conflict is the response.  There was one study where researchers had a space with a fixed area.  Within this they place a small population of rats.  They provided the rats with “X” amount of food and “X” amount of water each day.  At first, the amount of food and water was more than enough to support them.  As the population increased (and rats have a high growth rate) the researchers did not increase the amount of food and water – there began to be conflicts within the population – they began to fight – sometimes killing each other.

Homo sapiens have already dispersed to every corner of the planet.  There are a few islands, and the continent of Antarctica, we have not colonized – but there is little space for us to disperse more.  During my life I have heard discussions about colonizing the ocean floor and the moon.  People have talked about sending humans to Mars to deal with the overflow.  There have been experiments and trials to determine whether we could do this.  I know one marine scientist who lived on the bottom of the Caribbean for several months with others to “test” whether this would work.  He mentioned the crowded space did begin to wear on them.  He said at one point they were using masking tape to mark off individual’s space – even for their toothbrush.  I read about someone who lived in a cave for one year to see if they could live on the bottom of the ocean with only artificial light for the same amount of time.  There is the famous Biosphere 2 Project where they placed humans within a closed system to determine where we could inhabit Mars.  Humans have already spent much time in space orbiting Earth.  In each case there were physical and psychological problems.  It is still to be determined whether these dispersal ideas will work.

If dispersal is not the answer, then slowing population growth would be the next thing to address.  Many developed countries have slowed their growth.  Much of this has to do with more people going into professions that require college degrees – others are getting married later in life and having fewer children.  Much of it has to do with the role change for women.  More women are going to college and becoming professionals themselves – delaying marriage and the number of children even further.  The growth rate in Europe has slowed dramatically.  It has not surpassed 1% since 1961 and has slowed each year since.  The reasons can be attributed to those just mentioned – but Europe also has limited space.  Asia’s population growth rate has also declined, reaching less than 1% in 2016 – though it varies from one country to another.  South America also began a decline in the 1960s and is currently below 1%.  But the story in Africa is a little different.  Though there has been a decline in the growth rate, it did not start until around 2015 and is still above 2%.

The idea of “just stop having kids” is not as simple as you might think.  I was asked when I was teaching this course “Why are the birth rates are so high in developing countries where resources are already stretched?”  It is a fair question, but you must also understand how life works in some of these countries.  Many have large families to help run the farm or business, they cannot afford to hire labor.  I had a student from such a country in a class for one semester and he agreed.  He said his father ran a garage and his mother ran the restaurant attached to it.  His brothers and sisters were the employees.  In some cultures, particularly in the developing world, women are not going to school.  The children take care of the elderly and so families need to have employed sons to take care of them.  Knowing that health programs are not what they are in the developed world, parents will have several sons to make sure at least one survives long enough to land a good career and be able to support them.  Daughters do not help – so, they will continue to have children until this need is met.  In many of these cultures the daughters are expected to marry into money to help take care of them in their old age – and in some cases the daughters are expected to have sons as well – as early, and as many, as possible to prepare.

China had their famous “one-child only” policy, which began in 1979.  The purpose was to slow their growth rate and stabilize their enormous population.  Under this plan Chinese families were to have only one child, with fines assessed for any additional children.  Similar to other cultures, a couple would be expected to take care of both parents, and both sets of grandparents.  Under the one-child policy, this became a huge burden for a single couple.  In 2009 China changed the policy to where couples who had no siblings could have two children at no penalty.  There was the added problem of your only child being a female.  Females would be married off to another family leaving no one to support her parents.  China did relax the laws in such cases to allow extra children in hopes of having a son.  Under this new policy in 2016 there were 17.9 million babies born in China – a record for the 21^st century.  The growth rate has declined some since.  Some of this has to do with the cost of raising a child in China.

I used to show a film to my students addressing this issue.  In one part it showed an elementary school in Japan from the outside.  The camera slowly circled the school until you see the front door – the camera goes in.  As you go down the hallways, the classrooms are empty – until you reach this one classroom.  Within in sits a single 5^th grade boy – he is the only student in the entire school.  This showed how dramatic the population decline in Japan had become.  The problem here was similar to China’s – who would take care of the elderly.  This system is different though that in Japan the elderly are often taken care by a “social security” type system.  Young employed people pay a tax that supports the care of the elderly.  With no young workers, there are no taxes, and elderly care became a problem.  This system had to be changed.

One response to this problem has been paying families to have more children.  In some countries this has been in direct payments to the parents, in others it has been in the form of free childcare, paid time off for family needs, etc.  According to one report – this has not helped – birth rates continue to decline.  Part of this is a social issue, today’s young generation is not as interested in having large families, or families at all.  In the United States there has been a drop in birth rates, but this has not impacted us as much due to immigrants moving in and filling that niche.  This may be changing now.

The human population story is a very complicated and interesting one.  From a “natural history” side we understand the need to slow the growth rate.  From a cultural/economic one, we understand why/how this can be problematic.  Either way the large number of humans on the planet are stressing our resources.  The next few articles in this series will look at what resources we need to survive and how we are managing them.

References

Worldometer.  https://www.worldometers.info/world-population/.

Annual Population Growth Rate of Europe; 1950-2023.  Statista. https://www.statista.com/statistics/1251591/population-growth-rate-in-europe/#:~:text=The%20population%20of%20Europe%20decreased,and%20between%202020%20and%202023..

Population Growth in Latin America and the Caribbean Falls Below Expectations and Region’s Total Population Reaches 663 Million in 2024.  The United Nations. https://www.cepal.org/en/pressreleases/population-growth-latin-america-and-caribbean-falls-below-expectations-and-regions.

Population Growth Rate in Africa From 2000 to 2023.  Statista. https://www.statista.com/statistics/1224179/population-growth-in-africa/.

Two Child Policy. Wikipedia. https://en.wikipedia.org/wiki/Two-child_policy#:~:text=From%202016%20to%202021%2C%20it,for%20exceeding%20them%20were%20removed..

North, A. 2024. You Can’t Even Pay People to Have Kids. Population Connection. https://populationconnection.org/article/you-cant-even-pay-people-to-have-more-kids/#:~:text=Other%20countries%20have%20tried%20direct,of%20around%20%2430%2C000%20to%20newlyweds.