What Attenborough got wrong about the population crisis

Recently David Attenborough has been causing a bit of a fuss talking about the increasing human population in apocalyptic terms.

According to him some places, like Ethiopia, are in the grip of the Malthusian nightmare of starvation and disease caused by overpopulation. He has a point, but the example of Ethiopia is not a great one if he wants to say something about the developing world in general. For a start I’m not sure it’s particularly representative.

I can hear you now: “Phil – don’t have a go at lovely David Attenborough. He’s like the granddad I never had.” Or “Who are you criticise this national treasure? He’s achieved more than you ever will!” Or, if you read the Daily Mail, “I agree with Attenborough, we should let those scroungers starve!”

Two out of three of these people have a point (I’ll leave it up to you to guess which one I think doesn’t). It’s true – Attenborough has had a more positive influence on biodiversity conservation than me or any of my colleagues. His programs continue to inspire future conservation biologists all over the world and grip people in a fascination of the natural world. But this doesn’t make him perfect. I’m sure even Jesus had his faults – at the very least he (allegedly) liked a drink and hanging out with prostitutes.

First, Attenborough was right to raise the issue of increasing human population – I share some his concerns. Global human population is currently at an all-time high, having increased massively over the last century, and if estimates are to be believed it will continue to increase for about the next 50-100 years. This, along with changing human behaviour have led to an era of unprecedented human domination of the globe, is becoming known as the anthropocene.

Looks pretty bad – right?

Here’s why Ethiopia is not a great example when we’re talking population growth and the environment.

Here is the global distribution of percentage population growth for 2000-2010 in countries with a population of more than one million.

Global_percentageYou can see that most countries had increasing populations, with most having an increase of around 10%. If we break that up by human development index category (an index based on measures of poverty, education, equlaity etc) we get this:

Ethiopia_percentageCountries with the lowest HDI ranking tend to have higher population increases, and Ethiopia lies at the peak of the histogram.

Ethiopia_percentage_arrowHere, in fact.

So the population growth in Ethiopia is actually very representative of the poorest countries in the world.

However, if you look at how many people live on degraded land in Ethiopia it’s hardly surprising that there are so many hungry people in the country.

Ethiopia_degraded_arrowEthiopia is clearly not ‘normal’ in terms of the percentage of people who live in degraded lands. The mean global percentage is around 22% but in Ethiopia it’s around 72%. This has long been recognised as a problem and has probably resulted from people with relatively large families having only a small amount of farm land, and as a result this land cannot be left fallow and becomes quickly degraded making the situation worse.

So Attenborough is probably right about rising population in Ethiopia causing degradation. However, there is actually relatively little link between population growth and the percentage of people living in degraded land or indeed changes in forest cover on a global scale.

The links between land use change, degradation, population change and poverty are really difficult to generalise about. On the whole it looks like movement of people into natural ecosystems, rather than population increases by themselves, are the cause of much conversion to cropland. This movement can be driven by the perceived need to expand agricultural production, much of which is for foreign markets in the case of developing countries.

This combined with corruption can result in the economic benefits of exporting agricultural products not reaching the pockets of the average person in a developing country. Use of this land also stops production of crops to feed the native population which otherwise may have improved food security. Alternatively natural ecosystems could be saved from conversion.

Given all this, changing consumption habits in China & Brazil will have much greater environmental impacts than population growth in desperately poor countries. These changes in the environment may lead to further degradation of farmland and reduced food security.

So, Attenborough is right to be concerned about population growth – it is important to slow it as much as possible. But next time he speaks about it he would do well not ignore the issue of consumption.