Is Overpopulation Really Worth Focusing On?


For quite some time now I’ve wanted to write a post about population and the many concerns that people have about how a rising one will impact the environment but I’m also conscious of the fact that it is quite a contentious issue that draws religion and human rights into an argument that I feel I may not be best placed to contribute to.

On the other hand, the issue is one where I think a lot of confusion endures and I’d like to shed a little light on some of the most important aspects for those of you who don’t want to spend hours researching like I have done the last couple of days.

One thing I will say before I get into the nitty gritty is that I respect everyone’s right to have as many children as they wish. I am not, and would never, suggest population control.

How Big Are We Talking?

There are at least 3 main world population projections that I have come across; the UN World Population Prospects, the US Census Bureau projections and the Population Reference Bureau World Population Data Sheet (not free but you can access it here via Google Docs).

All 3 make predictions up to 2050 with the UN going all the way to the end of the century. Their respective figures look like this:

2050 Population
UN (medium-fertility variant) 9.306 billion
US Census Bureau 9.383 billion
Population Reference Bureau 9.624 billion

The UN also has 3 other variants based on low, high and constant fertility rates (constant being in line with current rates). They give the following population estimates:

2050 Population 2100 Population
Low fertility 8.112 billion 6.177 billion
Medium fertility 9.306 billion 10.125 billion
High fertility 10.614 billion 15.805 billion
Constant fertility 10.943 billion 26.844 billion

While the low fertility figure is wildly optimistic and the constant figure is highly unlikely, the true figure could realistically sit anywhere between the medium and high figures.

There are some startling statistics deeper down in the UN data tables but luckily some smart people have already done the analysis and a fact that I found interesting came from Hans Rosling of Gapminder who comments that:

The high-fertility countries (> 3 kids per women) are mainly in Africa and only have 18% of the world population = 1.2 billion people. They are expected to triple their population to 3.6 billion this century! The Low fertility countries are 40% of world population and will decrease their population and the intermediate are 40% will level off at 2050.

Essentially, the population conundrum looks like it will be played out in Africa primarily. If you are asking about China and India, it turns out that their future populations are less of an issue – although you cannot dismiss their past growth as not contributing to the problem (but then doesn’t that apply to all regions and countries?).

Another smart person who knows a thing or two about global population is former director of the United Nations Population Division, now research director at the Center for Migration Studies, Joseph Chamie. In an article on Yale University’s globalisation blog, he concludes that:

The demographic patterns observed throughout Europe, East Asia and numerous other places during the past half century as well as the continuing decline in birth rates in other nations strongly points to one conclusion: The downward global trend in fertility may likely converge to below-replacement levels during this century […] the world population could peak sooner and begin declining well below the 10 billion currently projected for the close of the 21st century.

Effectively then, we don’t know for sure what will happen to populations over the coming century. Due to the complexity of the situation and the length of time into the future that we are trying to predict, it was inevitable that variations would be considerable.

Does Population Growth = Disaster?

The short answer to this question is: it depends which disaster you are referring to.

Not enough? Ok, let me elaborate further in what I consider to be the 4 main areas.

Greenhouse Gas Emissions & Climate Change

There are two main points to make when it comes to emission increases due to a rising population:

  1. The areas of the world which are likely to see the largest growth in population are also some of the poorest areas where average carbon footprints are a tiny fraction of a typical westerner.

    Figures from this report by David Satterthwaite of the International Institute for Environment and Development (IIED) show that in the period 1980 – 2005 sub-Saharan Africa accounted for 18.5% of world population growth but just 2.4% of CO2 emissions growth. This is in stark contrast to North America which accounted for 4% of population growth and 14.2% of emissions growth.

  2. Will the world’s poor ever enjoy a lifestyle that is equivalent to more developed nations?

    The issue then becomes less about population and more about lifestyles and wealth and what people choose to do with that wealth.

    If average incomes rise significantly then the average carbon footprints will likely do the same. It is at this point that the population increase begins to matter.

The biggest issue might in fact be the population growth in North America where emissions per capita are some of the highest in the world. The continent is predicted to see a population increase between 2011 and 2100 of 51% and this sort of rise, while small in absolute numbers compared to Africa and Asia, represents a huge problem in terms of total emissions.

Furthermore, the huge populations across India and China may not grow as quickly in the future (and in fact may decline in China’s case) but the average incomes there could rise dramatically which again would be a far bigger problem when it comes to total emissions.

Food Supply

Another of the big issues that comes up whenever population growth is mentioned is the ability to feed everybody. Right now it is estimated that 870 million people worldwide are undernourished and the concern is that this figure will inevitably increase along with population.

That same report states:

The number of hungry declined more sharply between 1990 and 2007 than previously believed. Since 2007-2008, however, global progress in reducing hunger has slowed and levelled off.

Are both the planet and the human race able to sustainably grow enough food and raise enough livestock to feed 10 billion people and can these advances come quickly enough?

There are some interesting schools of thought in this area so I decided to cover them in a separate article about the ‘future of food‘ so I won’t go into depth about it here.

Fresh Water Supply

Possibly more of an issue than feeding the world is bringing enough fresh water to everyone. Already there are droughts and water shortages across the world and it is predicted to get worse. It won’t just happen where you’d imagine it to either (i.e. Africa and Asia), cities around the world may well struggle with supplies in the future with one study saying a billion people in cities could face long term shortages.

Food and water are not isolated entities either. Food requires a huge amount of water to produce and another startling study, this time by the Stockholm International Water Institute, argued that we need to reduce our meat intake hugely if water supplies are not to dry up. It says:

There will, however, be just enough water, if the proportion of animal based foods is limited to 5 per cent of total calories

Many parts of the world will also need to become far less wasteful in their use of water including here in the UK as I demonstrated a little while back.

You often hear it said that future wars will be fought over water and judging by what I’ve been reading, this may not be far from the truth.

There is one solution, although it is not ideal – desalination. This process already supplies many of the large cities in Australia, the Middle East and other parts of the world but it can consume quite a lot of energy. The only sustainable desalination solution is one powered by renewable energy, preferably a dedicated on-site facility where this is viable or at the very least a dedicated facility somewhere else feeding the equivalent electricity into the grid. People may have to pay higher water bills but it’ll still be a small price to pay in my opinion.

Energy Supply

In a way, you can relate the future energy requirements of a growing population to the emissions section above. In other words, yes the world’s energy demands will increase but it is not going to be because of population growth primarily. It will once again come down to rising incomes in parts of the world such as China and India and increased consumerism in other western nations.

Of course a greater amount of energy will be required in the poorer parts of the world but there is a good chance that much of this is going into manufacturing of products for western markets.

In other words, next time you see “made in China” or “made in India” on one of your products, remember that the carbon footprint of that product belongs to you the owner and not the person who made it.

Looking Into My Crystal Ball

While I’ve covered what I consider to be the 4 biggest areas of concern, there are an innumerable number of other issues that will rear their ugly heads in a future where the human population on this planet reaches 9 or 10 billion or more.

As I have shown, not all of the problems are necessarily caused by the absolute size of the population but rather by the comparative carbon footprints of today’s and tomorrow’s average person. If people in developing countries genuinely want to live a life such as we enjoy in the developed world, we have a big problem on our hands. Should this be the case, the one and only solution as far as I can tell is gradually changing this “western” culture to one where we consume less of everything.

My biggest worry is not whether we can advance technology enough to address the problems of a growing population, but rather whether we can advance it quick enough and in all parts of the world. We already live in a world of huge inequality and even if I put my optimist hat on, I can only see this scenario continuing ad infinitum.

What do you think about a growing population? Let me know your thoughts below.

Steve (156 Posts)

I am chief writer and editor on Green Steve. Blogging since 2011, I like to delve into a wide number of topics to help people reduce their carbon footprint. You should follow me on Twitter here. And add me to your Google+ circles here.

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