The trend of population ageing is presently on the increase because the people are living longer now due to better food and healthcare. The falling fertility rate is reducing the proportion of younger people. Thus most of the countries are now facing the challenge of greying population. According to UN figures, over the past half century, the median age of the world population has risen from 23.5 to 29.6, but by 2050 it will go upto 37.8. In the MDRs, the number of persons above 60 years have exceeded that of children under 15 years of age. Thus by 2050, the median age in MDRs will rise from present 37.8 to 45.6. Europe will be the most affected region where the older people (60+) will constitute one-third of the population by 2050. Spain will be the oldest nation in 2050 with a ratio of 3 to 1 between older and the persons below 15 years.
On the other hand, the aging has been very slow in the LDRs with the median age rising from 21.3 in 1950 to 24.4 in 2000 and projected 36.7 in 2050. Over the past 50 years, LDRs old people aged 60+ has grown by 264 million out of a total increase of 3.2 billion. But in the next 50 years, the number of older people (sixty plus) in the less developed regions will rise by 1221 million accounting for 2/5th of the total population increase. Thus by 2050, the LDRs will reach the same level of population ratio as the MDRs had in 1998, with older people outnumbering the children below 14.