The mean length of life (life expectancy at birth) in the world is 68 years in 2010. It varies by a factor of two between the countries with the longest life expectancy and those with the shortest.

Contrasting situations

In the last fifty years, the mean length of life has risen by more than 20 years, from 46 years in 1950-55 to 68 years in 2005-2010. But situations are highly contrasting across the world, and life expectancy in many developing countries is well below this mean level. While a European lives for 76 years on average, an African lives for only 55.

Life expectancy is now increasing almost everywhere

In the industrialized world, life expectancy is still increasing and exceeds 80 years in most countries. It is also rising in countries where economic development and health improvements are more recent, such as China, India and the countries of South America.
On the other hand, life expectancy is now falling in certain countries of the former Soviet Union which formerly ranked among world leaders (Russian men have a life expectancy of 61 years in 2010, compared with 64 years in the 1960s). Likewise, average length of life is stagnating or decreasing in countries of sub-Saharan Africa severely hit by the AIDS epidemic or regularly ravaged by war. It has fallen to 52 years in South Africa and 48 years in Sierra Leone for example.

Future prospects

According to the United Nations, world mean life expectancy should reach 76 years in 2050. This hypothesis assumes that the downtrend will be reversed in countries where length of life has fallen recently and that diseases "of civilization" (obesity, cardiovascular disease, cancer) will be contained, notably in the South were their prevalence is set to increase.