• The population in developing regions is projected to increase from 5.9 billion in 2013 to 8.2 billion in 2050. In contrast, the population of developed countries is expected to remain largely unchanged during that period, at around 1.3 billion people.

• Africa’s population could increase from 1.1 billion today to 2.4 billion in 2050, and potentially to 4.2 billion by 2100.

• The number of children in less developed regions is at an all-time high at 1.7 billion. In those regions, children under the age of 15 account for 26 per cent of the population. In the poorest countries, children constitute 40 per cent of their populations, posing huge challenges for providing education and employment.

• In wealthier regions, by contrast, children account for 16 per cent of the population. In developed countries as a whole, the number of older people has already surpassed the number of children, and by 2050 the number of older people will be nearly twice the number of children.

• Low-fertility countries now include all of Europe except Iceland plus 19 countries in Asia, 17 in the Americas, two in Africa and one in Oceania.

• The populations of several countries are expected to decline by more than 15 per cent by 2050, including Belarus, Bulgaria, Croatia, Cuba, Georgia, Latvia, Lithuania, the Republic of Moldova, Romania, Russia Serbia, and Ukraine.

• Life expectancy at birth for the world as a whole rose from 47 years in 1950-55 to 69 in 2005-2010 and is projected to reach 76 in 2045-2050 and 82 years in 2095-2100.