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Population spike—the good news or the bad news?

A population spike is good news, right? More customers, taxes, opportunities and overall development of humanity. Well, there is bad news too.

The population spike that humanity is in right now is unprecedented in evolutionary history. There’s never been a single species able to appropriate resources and energy to itself at such a rate and extent as Homo sapiens have since we figured out how to use exogenous energy. 

In short, we eat and drink fossil fuels and turn them into more people.

The neoliberal politician, his corporate buddies, and the talking head economists see population growth and rejoice—more votes and taxes, more sales, and theories proven.

Other people, blessed with an ounce or two of common sense, know that whilst more people might be good for business, sooner or later, the resources and energy that power the commerce people undertake will become scarce. They know this because the planet is finite. 

They also know there is only so much waste that a finite planet can absorb.

A population spike is both good and bad news.

Good news or bad news?

Whenever somebody comes up to you and says, “do you want the good news or the bad news?” Which do you go for? 

I’m guessing most people will go for the ‘good news’—feel good first, cop the bad news later. Maybe others are inclined to get the medicine out of the way and look forward to the good news. 

Angela Legg, a researcher in psychology at the University of California, Riverside, found that the answer depends on whether you are the giver or receiver of the bad news. 

Experiments showed that an overwhelming majority of receivers—more than 75%—wanted the bad news first. Get it over and use the good news to end on a high note. Around 65% of news givers chose to give the good news first, then the bad news. No one enjoys giving bad news because delays make the recipient anxious. 

But the research also suggested that ‘good news first, then bad’ could be a sound strategy if the goal is to get someone to change a behaviour—when, for example, Legg says, “you are giving feedback to a patient needing to lose weight, who has to take action. The recipient doesn’t feel good about the news but may do something about it.

I’m a ‘bad news first’ type of person perhaps because I am a pragmatologist and tend to take any good news with scepticism. My fault, of course. Only there is a problem with this strategy. If the bad news is terrible, no amount of good news can give me solace. 

A better approach would be to avoid bad news altogether. 

I am cocooned within the safety of a narrow worldview. Anything outside my little bubble can be ignored as irrelevant or untrue. And nothing can disturb any good news, for I would be crazy to bring bad shit into my bubble. 

Givers or receivers fear bad news. If the truth is sinister, we are programmed to fight, flee, or freeze when it hits. In a world where some news is so bad that it’s overwhelming with no apparent solutions or ways to cope, denial is a great tactic. My dissonance accommodates all three very nicely.

Now, back to the population spike. 

Is it good news or bad?

Humans use resources to make more

If you have six minutes free today, watch this video from the American Museum of Natural History. It is scary but hugely informative. It points to many facets of human existence and what has made humans successful in numbers and reach—adaptability, mobility, and technological advancement.

Skill, tenacity and access to a fossil army of workers in the form of coal, oil and gas have allowed humans to hunt and fish everywhere and to convert over half the habitable land on Earth into a food factory.  The consequence has been more humans, a population spike.

Here is what that population growth looks like on a linear time axis.

graph of human population size since 10,000 BC sowing the population spike since 1800

It is worth pausing on this graph. 

For 290,000 years, Homo sapiens, modern humans, were just large mammals, milling about the landscape in small groups. Then we invented agriculture roughly 12,000 years ago (10,000 BCE on the graph), and only a little happened population-wise. There was no immediate population spike, but the early stages of an exponential growth pattern typical of any organism that finds access to new resources.

We may have continued on this trajectory, colonised the globe, and increased to 1 billion people today. Instead, we see the graph near vertical because we changed everything.

The Industrial Revolution kicked off in the late 1800s (above the 2 in 2019 on the chart), and the population spike started. Almost overnight, there is ever more energy and technology to access resources that we use to make things… and more people

In the last 100 years, we have added 6.2 billion people.

Astonishingly 7% of all humans that have ever lived are alive today.

Thomas Malthus was right.

In 1798, when the global population was around 1 billion, Thomas Malthus (1766–1834), an English cleric, scholar and influential economist, published an essay entitled ‘An Essay on the Principle of Population’… anonymously. 

In the article, Malthus observed that an increase in a nation’s food production improved the well-being of the populace, but the improvement was temporary because it led to population growth, which in turn restored the original per capita production level. 

In other words, humans tended to utilise abundant food and resources for population growth rather than maintaining a high standard of living, a view known as the “Malthusian trap” or the “Malthusian spectre”.  

In other words, humans were like every other organism on the planet; we make more.

Why anonymously?  

In the newly minted Industrial Revolution about to make industrial nations wealthy, powerful and global colonists, it was heretical to suggest that wealth would be thrown away to more people. Wealth would beget wealth.

I am sure you are familiar with this tension between the masses and the elites as the core of modern history and of politics to this day.

But more making is a powerful force.

Frontpiece of the essay by Thomas Malthus published in 1798

By The original uploader was Lupo at English Wikipedia. – Transferred from en.wikipedia to Commons., Public Domain, 

The power of population

Malthus saw population growth as inevitable whenever conditions improved, thereby precluding real progress towards a utopian society 

The power of population is indefinitely greater than the power in the earth to produce subsistence for man“.

Malthus also concluded that populations tended to grow until the lower class suffered hardship, want and greater susceptibility to famine and disease. This view is sometimes referred to as a Malthusian catastrophe. All this opposed the popular belief in 18th-century Europe that society was improving and, in principle, perfectible. As an Anglican cleric, his solution was typically damning…

 “the superior power of population is repressed by moral restraint, vice and misery

By hinting at what the modern science of population ecology understands as population growth when resources are plentiful and collapse through competition when resources inevitably become constrained, Malthus was attacking two sacred cows—dominion and primacy.

He was smart enough to understand both population ecology and self-preservation.

Malthus could never have imagined the population spike of the 20th century.

The population spike begins.  

When Thomas Malthus was born in the mid-1700s, the estimated global population size was between 750 and 800 million. Around this time, James Watt was about to figure out how to use coal in a piston steam engine. 

When Malthus died, there were 1.2 billion people, a 50% increase in numbers, although he would not have known these figures. However, he would have read in the paper the opening of the Liverpool to Manchester Railway in 1830, the first commercial use of steam locomotives for people and freight.

He saw the change in his life but could never have imagined what the global population would become.

300,000 years to get to 1 billion
200 years to add another 7 billion 

Escaping the Malthusian trap

Imagine the ghost of Malthus. It waves its finger at us with a smug look on its eerie face. 

Many others have echoed the views of Malthus over the years because the data backs him up, and evidence from population ecology has demonstrated the mechanisms. As humanity acquired more resources to grow food, we made more people. 

Only the Malthusian prediction of catastrophe has not happened. 

Humanity has managed to stave off ‘vice and misery’ for some, but not everyone. There are close to 1 billion people food insecure and another 3 billion malnourished. Still, for the other 4 billion, there is food and for some of those it is a time of unimaginable plenty. At the moment, the majority of people in mature economies eat and live better than the kings of old, quite literally.

The good news is that we have escaped the Malthusian trap and continued converting natural resources into more people.

Indeed, we have invented an economic model requiring such an outcome to persist. 

More people means more customers and more spending for more profit. 

Good news all around.

Beating density dependence.

Thomas Malthus would have recognised the theories of density-dependence that modern population ecologists have developed and tested.

The basic form of density-dependence goes something like this.

When resources become limited, organisms respond through competition. The stronger or more competitive individuals continue to do well, the less competitive do not have enough energy, and one or more things happen. Fertility decreases, growth slows and mortality increases, typically affecting the young first but eventually the adult population. 

If resources decline or numbers increase or both happen, competition increases, resulting in less reproduction and more deaths (mortality). This slows population growth or even reduces population size, easing competition pressures.

If resources increase, the opposite happens: more reproduction and improved survival allowing numbers to increase.

Ecologists have observed these outcomes in nature time and again. I even found density-dependence working in populations of a woodlouse, the common pillbug Armadillidium vulgare, that occupied my PhD research back in the day.  

Evolution has given organisms any number of subtle mechanisms to reduce competition’s impact through density-dependent effects, stabilizing populations early before they expire. This is remarkable because the instinct in all individuals to increase the proportion of their genes in their population is strong (reproduce now) but so is the benefit of persistence (survive to reproduce later). 

One species is especially good at subverting the cruder density-dependent mechanisms of high juvenile mortality and lower fertility that result in population regulation, the large ape species Homo sapiens

Juvenile mortality has declined around the world as a result of improved primary health care and nutrition. 

And at the same time, fertility rates have stayed high, again thanks to nutrition and health care, until economic maturity kicks in and births per woman decline. 

Better-fed adults with access to primary health care have slowed adult mortality, increasing life expectancy almost everywhere, although that curve is starting to reverse with the rise of lifestyle-related diseases in mature economies. 

How did humans beat density dependence?

Simply put, we subverted competition by channelling nature into food production through energy subsidies. 

Using technology, we went beyond people power to horsepower to the near-unlimited power of fossil fuels. This extra energy allowed us to change vegetation into farms and move fertilisers and pesticides to the fields and the foodstuffs around to where the people live.

So far we have avoided the Malthusian trap.

The eighteenth-century Malthusian prediction of population growth out-stripping food production has not yet come to bear. Unprecedented agricultural land expansions since 1700, and technological innovations that began in the 1930s, have enabled more calorie production per capita than was ever available before in history. This remarkable success, however, has come at a great cost. Agriculture is a major cause of global environmental degradation. Malnutrition persists among large sections of the population, and a new epidemic of obesity is on the rise. We review both the successes and failures of the global food system, addressing ongoing debates on pathways to environmental health and food security. To deal with these challenges, a new coordinated research program blending modern breeding with agro-ecological methods is needed. We call on plant biologists to lead this effort and help steer humanity toward a safe operating space for agriculture.

Ramankutty, N., Mehrabi, Z., Waha, K., Jarvis, L., Kremen, C., Herrero, M., & Rieseberg, L. H. (2018). Trends in global agricultural land use: implications for environmental health and food security. Annual review of plant biology, 69, 789-815.

Some bad news.

The bad news is we believe we are immune to the consequences of density dependence—we think we have beaten nature.

We have not.

Density-dependence theory is laboured here because the mechanisms are fundamental. They are with us, and no cognitive dissonance will change that fact. Humanity is careering towards a cliff of resource scarcity where density-dependent mechanisms kick in hard to make life very uncomfortable for many of the global population. 

Harbingers are already with us. Just ask the Lebanese.  

When resources become scarce, competition kicks in, and a population crashes. Not to zero necessarily, but large numbers of individuals die due to resource depletion. 

It is why the population graph will be a population spike and not a step.

What sustainably FED suggests.

Homo sapiens have avoided the Malthusian trap, fair enough. 

We grow enough food to feed the current and potential future human populations. We could feed everyone well if we fix inequity, food distribution problems, and some curious dietary choices.

However, this temporary avoidance of density dependence on the back of fossils is precarious. It does not mean that the Malthusian trap can’t catch us in an instant. At any moment, the food supply could fall below demand and competition for food kicks in. Should this reach extremes, a very ugly population crash is likely.

Alright, that’s the bad news. 

The way to avoid such a doomsday scenario is to put humanity’s considerable intellectual energy and practical skill into working on the things that matter—soil, food production, diet and understanding the ecology that links these together. 

The excellent news from having a population spike is the intellectual power represented by 8 billion people. It is possible, even probable that we will figure out a way to ostracise the ghost of Malthus and his pointy finger.

Hero image modified from photo by daria lisovtsova on Unsplash


Mark is an ecology nerd who was cursed with an entrepreneurial gene and a big picture view making him a rare beast, uncomfortable in the ivory towers and the disconnected silos of the public service. Despite this he has made it through a 40+ year career as a scientist and for some unknown reason still likes to read scientific papers.

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