How many people can our planet really support?

p03m9r5d

Source: BBC

Overpopulation. It is a word that makes politicians wince, and is often described as the “elephant in the room” in discussions about the future of the planet.

You often hear people citing overpopulation as the single biggest threat to the Earth. But can we really single out population growth in this way? Are there really too many people on our planet?

It is clear to all of us that the planet is not expanding. There is only so much space on Earth, not to mention only so many resources – food, water and energy – that can support a human population. So a growing human population must pose some kind of a threat to the wellbeing of planet Earth, mustn’t it?

Not necessarily.

Earth is not getting any bigger (Credit: Mike Kiev/Alamy Stock Photo)

Earth is not getting any bigger (Credit: Mike Kiev/Alamy Stock Photo)

“It is not the number of people on the planet that is the issue – but the number of consumers and the scale and nature of their consumption,” says David Satterthwaite, a senior fellow at the International Institute for Environment and Development in London. He quotes Gandhi: “The world has enough for everyone’s need, but not enough for everyone’s greed.”

The global impact of adding several billion people to these urban centres might be surprisingly small

The number of “modern human beings” (Homo sapiens) on Earth has been comparatively small until very recently. Just 10,000 years ago there might have been no more than a few million people on the planet. The 1 billion mark wasn’t passed until the early 1800s; the 2 billion mark not until the 1920s.

As it stands now, though, the world’s population is over 7.3 billion. According to United Nations predictions it could reach 9.7 billion people by 2050, and over 11 billion by 2100.

Population growth has been so rapid that there is no real precedent we can turn to for clues about the possible consequences. In other words, while the planet might hold over 11 billion people by the end of the century, our current level of knowledge does not allow us to predict whether such a large population is sustainable, simply because it has never happened before.

We can get clues, though, by considering where population growth is expected to be strongest in the years ahead. Satterthwaite says that most of the growth over the next two decades is predicted to be in urban centres in what are currently low and middle-income countries.

It is not the number of people on the planet that is the issue – but the number of consumers and the scale and nature of their consumption

On the face of it, the global impact of adding several billion people to these urban centres might be surprisingly small. This is because urbanites in low- and middle-income countries have historically consumed little.

The emissions of carbon dioxide and other greenhouse gases give us a good indication of how high consumption is in a city.

“We know of cities in low-income nations that emit less than one tonne CO2-equivalent per person per year,” says Satterthwaite. “Cities in high-income nations [can] have six to 30 tonnes CO2-equivalent per person per year.”

Citizens of more affluent nations leave a much greater footprint on our planet than people living in poorer countries – although there are exceptions. Copenhagen is the capital of a high-income nation – Denmark – while Porto Alegre is in upper-middle-income Brazil. Living standards are high in both cities, yet per capita emissions are relatively low.

Read more

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.