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Population – the good news or the bad news?

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

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 much more inclined to get the medicine out of the way and look forward to the good news. 

Angela Legg, a PhD student 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 with and use the good news to end on a high note. 

Around 65% of givers of news chose to give the good news first, then the bad news. Apparently, 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 useful 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 not much of a cheerleader and tend to take any good news with a degree of scepticism. My own fault of course.

The problem with this strategy is if the bad news is really bad, no amount of good news can give me solace. 

A better strategy for most people is to avoid bad news altogether. 

Cocooned within the safety of our worldview, anything outside our limited bubble is ignored as being either irrelevant or simply untrue. And nothing can disturb our good news for we would be crazy to bring bad shit into the bubble. 

In a world where some of the news is so bad that it’s overwhelming with no obvious solutions or ways to cope, denial feels like a great tactic. 

Giver or receiver, as individuals we fear bad news. If the truth is bad for us, we are programmed to fight or flee or freeze when it hits. Dissonance accommodates all three very nicely.

Some good news first

The population spike that humanity is in right now is unprecedented in evolutionary history. There’s never been an organism that has been able to appropriate resources to itself at such a rate and extent. 

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: adaptability, mobility, technological advancement. 

What an alarming trajectory all of those skills and motivations have put us on. We are literally climbing at an unprecedented rate of numbers.

Many people have warned of resource use consequences all the way back to Thomas Malthus (1766–1834). The English cleric, scholar and influential economist wrote a book in 1798 ‘An Essay on the Principle of Population’ where he 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 had a propensity to utilize abundance for population growth rather than for maintaining a high standard of living, a view that has become known as the “Malthusian trap” or the “Malthusian spectre”.  

In other words, humans were like every other organism on the planet — we make more… 

…and recently we have become exceptionally good at it.

The power of population

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

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

Just before Malthus was born in the mid-1700s the estimated global population size was between 750 and 800 million people. 

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 but could never have imagined what the global population would become.

200,000 years to get to 1 billion

200 years to add another 7 billion 

Many others have echoed the views of Malthus over the years and the data backs him up. As humanity acquired more resources we made more people. The Malthusian prediction of catastrophe might be a bit off given we have managed to stave off ‘vice and misery’ for the most part, but there is no doubting the power of population size to impact upon resource use. 

Escaping the Malthusian trap

The good news is of course that we have escaped the Malthusian trap and continued to convert natural resources into more people. 

Indeed, we have invented an economic model that requires such an outcome for it to persist. More people means more customers and more spending for more profit. 

Good news all around.

Beating density dependence

Modern population ecologists have developed and tested theories of competition for resources among organisms that Thomas Malthus would have recognised.

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 then competition increases and the consequence is less reproduction and more deaths (mortality). This slows population growth or even reduces population size easing the pressures of competition.

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 and call it density dependence.  

Evolution has given organisms any number of subtle mechanisms to reduce the impact of competition through density-dependent effects thereby 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). 

The large ape species Homo sapiens has subverted early density-dependent mechanisms. 

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 we beat density dependence?

In the simplest terms, 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 fertilizers 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 that Homo sapiens assumes that they 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 real. They are with us and no amount of cognitive dissonance is going to 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 a large proportion of the population. 

When this happens in nature there is a population crash. Not to zero necessarily but large numbers of individuals die as a result of resource depletion. 

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. If we fix inequity, food distribution problems, and some curious dietary choices those people could all be fed well.

However, this avoidance of density dependence 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 possible.

The only 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.

sustainablty FED

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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