Imagine all the people sharing all the world. When Lennon wrote the lyrics in 1971, the world population was 3.8 billion. In the coming days it will hit seven billion.

swissinfo.ch spoke to demographics expert Philippe Wanner about the rise and rise of the global population and asked whether we should fear the burden of the additional two to three billion people expected to be added to the planet in the next 50 years.

During the 20th century, the world population exploded, passing from 1.6 billion people in 1900 to 6.1 billion in 2000. This trajectory is expected to continue throughout the 21st century with the arrival of the seven billionth world citizen on October 31, according to UN predictions.

The world’s resources are finite while our capacity for consuming them has consistently accelerated. While many fear this dynamic is a recipe for disaster, Wanner of Geneva University argues that it is not safe to make assumptions.

swissinfo.ch: On October 31 the Earth’s population will cross the seven billion threshold according to the United Nations Population Fund. Is this cause for humanity to celebrate or lament?

Philippe Wanner: It’s rather good news because this trend is the result of a series of favourable conjunctions: a decrease in the infant mortality rate on the one hand, and the growth in life expectancy on the other. The number of survivors at all ages is growing and I consider that a positive thing.

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