Population growth

The latest population estimates produced by the United Nations Population Division (pdf) suggest that the current world population of close to 7 billion is projected to reach 9.6 billion by the middle of this century.

World population is estimated at 7.2 billion as of 2013, with an annual growth rate of about 1.2%, which adds about 86 million people per year. It is projected that the world’s population could ultimately stabilize at about 10-11 billion people, sometime later this century, but of course this projection is highly uncertain. Almost all the projected growth will take place in developing countries. How are we going to meet the human needs of 3 billion more people? At the same time, if global fertility continues to decline, this will lead to an increasingly aged population. How will they be cared for?

While many commentators emphasize the problems caused by human population growth, others suggest that it is not so much population size that is important, but patterns of consumption. This is an area of very contentious debate.

Which is the most important driver of environmental change – human population growth, or patterns of consumption? You might consider it self-evident that a rapidly increasing human population is a major determinant of human impacts on the global environment. However, some people – notably those in richer countries – consume a lot more than others. This question is therefore not just of academic interest, but is one of great political importance. It is also very politically sensitive. If there is general agreement that population growth is a major problem that needs to be solved, what can actually be done about it? As you reflect on this point, you might begin to understand why many environmental organisations, and even the United Nations, tend to avoid raising this issue.

Further reading:

Population Reference Bureau http://www.prb.org/Educators/TeachersGuides/HumanPopulation/PopulationG rowth.aspx

UN Population Division http://esa.un.org/unpd/wpp/index.htm. There are some great interactive tools on this site, where you can see current population estimates for different countries.

U.N. Economic and Social Council, Commission on Population and Development. 2009. World Demographic Trends: Report of the SecretaryGeneral. 1-22. New York: United Nations E/CN.9/2009/6.

From the blog:

Earth Overshoot Day  (1/3)[Dave Sanderson, 8 August 2016]

Andrew Hunter-Rossall I’m a huge fan of Hans Roesling, the Swedish statistician who has done a lot of work on data visualisation and does a lot to shatter myths about the “developing world”, population, etc. It’s very interesting that many of our preconceptions about the world are based on how the world was in the 1950s and 1960s, and we don’t seem to have collectively updated our ideas since then.

This video is from a series Hans Roesling did for the BBC about population. The series was called “Don’t Panic”.
The section relevant to this debate is the section between 19:12 and 26:15 or so, but please do watch the whole thing.

In summary (though Hans Roesling’s explanations are far clearer than mine, so please do watch!), most population growth is happening because larger cohorts are growing older. Eg if there are signicantly more 30-45 year olds now than 45-60 year olds, then in 15 years time the number of 45-60 year olds will have increased. There is also a small amount of population growth due to longer life expectancies. Very little of the global population growth is related to the number of children people are having – indeed we’ve already reached “peak child” – there are 2 billion children in the world and this number has levelled off.

With this in mind, how do we reduce population sizes?! I’m not making a value judgement about whether focussing on population is a noble goal, but I simply think that the majority of the work on this aspect of global development has been done, or is well on the way to happening. Most countries are well on their way to stable populations in terms of the number of children (ie about 2 per family).

The other aspect of consumption is “consumption per capita” (ie consumption per capita x population = total consumption). Given that population growth is very likely to put us at between 10 and 12 billion people by mid century, and given that most of this growth will be in countries with lower per capita consumption, and given that any efforts to reduce population are likely to have only marginal impacts on this total population, and are likely to do so only in the lowest consumption countries, is there not far, far more scope for reducing total consumption by focussing on the over-consumption of rich nations and emerging economies rather than population?

I certainly think there is. I think reducing consumption of petrol, gas, and electricity through energy efficiency and localisation, and replacing energy sources with cleaner alternatives, along with reducing consumption of meat and dairy, are by far the biggest opportunities for reducing human impact on the environment.

Population stability or contraction is an inevitable consequence of development. As we improve global education, healthcare, access to contraception, and women’s rights, we inevitably see populations move towards long-term stability. These things are all goals that the UN and many NGOs are working towards, and the consequences can be seen.

But reducing consumption per capita is in no way inevitable. In fact historically, development has always been strongly linked with increasing consumption per capita. In this area we need a radical, new global paradigm, and there is a lot of work to be done. That is why I think the focus needs to be on reducing consumption per capita, not on population.


David Sanderson It is very nice to be able to believe what Rosling says but sadly he is wrong. This video was produced in 2014; the latest UN Stats released since then show we do NOT have ‘peak child’ and unless certain things happen, birth rates will NOT level off! Beware his circular argument; things will be alright so we don’t need to do anything. UN projections are just that; projections. If we do NOT act to encourage smaller families, then the higher projections are likely to occur, not the lower ones.

Should we be worrying about the global population? (2/3) [Dave Sanderson, 9 August 2016]

Does the economy need a growing population? (3/3) [Dave Sanderson, 10 August 2016]

Andrew Hunter-Rossall “Population may increase, GDP may increase, but if GDP increases by the same or a smaller percentage, GDP per head decreases so on average people become poorer. GDP / head is thus a much better measure than simple GDP.”

This paragraph made me smile. I remember having this conversation with some council officers in Sefton years ago. Discussing there long term planning documents, where they were arguing that increasing housing stock was important for economic growth in the area. Now aside from all other considerations about whether increasing housing stock was necessary to meet demand, or to “do our bit” for national housing shortages, etc, I questioned them on this argument about growth. Is the expected percentage growth in the income of the area greater than the expected growth in population? They didn’t seem to be able to understand the concept at all. They were completely stuck on the fixation that economic growth was a Good Thing, regardless of how it was achieved, whom (if anyone) it benefitted, etc.

Second comment for now, more to come later, I’m sure! You mention the Ponzi scheme again in this article. Couldn’t agree more with that concept! But what is the alternative? Three possible solutions that I can think of:
* People work longer/ retire later and support themselves. This would be understandably unpopular!
* We aim for a standard of living for the retired which can be supported by a steady population younger than them. In the short term this would lead to a reduction in living standards for the elderly, some of whom are already very poor. In a long term future of greater equality, this might be possible.
* Each generation supports itself, investing and saving for it’s retirement years. This seems the most sensible as it controls for fluctuations in population. The downside would be getting there! We’ve set up the Ponzi Scheme (eg in our state pension system), and getting it on to sustainable footing will be difficult.

Also from the blog:

New research suggests that family planning plays a significant role in achieving sustainability gains [Anders Lorenzen, 25 July 2016]

Research papers:

News articles: