Global population hits 8 billion as growth poses more challenges for the planet

The world’s population will reach 8 billion people on Tuesday, representing a “milestone in human development” before birth rates start to slow, according to a projection from the United Nations.

In a statement, the UN said the figure meant 1 billion people had been added to the global population in just 12 years.

“This unprecedented growth is due to the gradual increase in human lifespan owing to improvements in public health, nutrition, personal hygiene and medicine. It is also the result of high and persistent levels of fertility in some...