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The big question: too many people on the planet?

By Katherine Aitchison, on 17 May 2013

Earth, courtesy of Kevin M Gill on Flickr

Earth, courtesy of Kevin M
Gill on Flickr

There are currently 6.9 billion people living on our planet and with that figure set to rise, many people are worried about how long the Earth will be able to sustain us all and cope with the damage that we are inflicting on it.

The UCL Grant Museum of Zoology has a “case of extinction” featuring, among others, dodo and Tasmanian wolf (thylacine) specimens. Both of these species were hunted to extinction by humans and since their deaths many other species have faced the same fate. Which led Dean Veall, the museum’s learning and access officer, to ask the Big Question: are there too many people on the planet?

When the question was first posed to a packed JZ Young lecture theatre, after a glass of wine and a mooch around the Grant Museum’s always fascinating collection, the answer from the crowd was a resounding ‘yes’. But over the course of the night, we stood to have our opinions tested and potentially changed.

The three speakers who joined us all hail from different departments of UCL and all brought a different aspect to the discussion.

They were: Professor Georgina Mace of the Department of Genetics, Evolution and Environment; Professor Mark Maslin of the Department of Geography and Professor Judith Stephenson of the Institute for Women’s Health.

To begin with Professor Mace gave us a frightening statistic: the human population has doubled over the past 50 years, which has coincided with an average drop of 30% in the population of every wild species. This would seem to suggest that there are, indeed, too many of us.

However, she then went on to argue that we are not using up our planet’s resources; in fact, theoretically, the planet is capable of producing enough food to sustain 10 billion people or more. The problem is access to, and distribution of, that food across the globe.

The major factor that she warned against was the huge amount of wastage we as a species, and particularly in the western world, produce. If we can cut down on that wastage and improve the ways that we use the planet’s resources, be that food, water or fuel, the Earth can sustain many more people than are currently alive.

Professor Maslin agreed that there aren’t too many people on the planet; he sees political ideologies as the major problem facing the world. He suggested that we need to adapt our 19th century political viewpoints for our 21st century problems.

Rather than worrying about the actual number of people on the planet, we should be asking how we can minimise climate change, eliminate poverty and ensure global security in the face of an expanding population.

One of the objects that he had brought to illustrate his point was a sci-fi novel set on an imaginary world with a radically different political system to those seen in the world today.

Why, he argued, if we’re capable as a species of imagining such vastly different political structures, can we not implement them?

Technology develops at an incredible rate yet our politics is the same as it has been for hundreds of years; the number of people on the planet is irrelevant, it’s the way we manage them and our resources that needs to be discussed.

The last speaker of the evening was Professor Stephenson who changed tack slightly to discuss the way that populations expand.

She began by taking us back to the third century when there were roughly 1 billion people on Earth and the birth and death rates were more or less equal, which meant that the population stayed at about the same size for many years.

The change came when the death rate began to decrease in the late 18th century, as advances in medicine and hygiene allowed people to live longer. As there was a decrease in child mortality, families began to have fewer children as there was an improved chance that each child would reach adulthood.

This is what is known as the transition and leads to a larger, older population and to urbanisation. The speed at which it occurs dictates population growth.

If the death rate decreases quickly but the birth rate is slow to follow then the resulting population increase is greater than if the birth rate also falls quickly.

For this reason Professor Stephenson is keen to advocate effective family planning and quoted the example of Oman where the transition has happened so quickly that in one generation the average woman has gone from having 10 or more children to perhaps two or three.

However  she was quick to point out that coercive strategies, such as China’s one child policy, are often ineffective and that it is much more efficient to educate the population and help them plan their family rather than dictate family sizes.

As I’ve come to expect from Grant Museum events, this was an entertaining, yet thought-provoking, evening with excellent speakers and some truly important points up for discussion.

It was reassuring to learn that top academics don’t feel we are overpopulating the planet, but that there are some very serious issues facing the world, which an increasing population is only going to exacerbate unless we begin addressing them soon.

The main message to come out of the evening was neatly summed up by Professor Mace who said we need “collective will and good leadership to solve these global problems”.

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