WUNRN
Pew Research Center
http://www.pewforum.org/2015/04/02/religious-projections-2010-2050/
The Future of World Religions – Population Growth Projections
2010 - 2050
Why
Muslims Are Rising Fastest and the Unaffiliated Are Shrinking as a Share of the
World’s Population
The
religious profile of the world is rapidly changing, driven primarily by
differences in fertility rates and the size of youth populations among the
world’s major religions, as well as by people switching faiths. Over the next
four decades, Christians will remain the largest religious group, but Islam
will grow faster than any other major religion. If current trends continue, by
2050 …
These are
among the global religious trends highlighted in new demographic projections by
the Pew Research Center. The projections take into account the current size and
geographic distribution of the world’s major religions, age differences,
fertility and mortality rates, international migration and patterns in
conversion.
As of 2010, Christianity was by far the world’s largest religion, with an
estimated 2.2 billion adherents, nearly a third (31%) of all 6.9 billion people
on Earth. Islam was second, with 1.6 billion adherents, or 23% of the global
population.
If current
demographic trends continue, however, Islam will nearly catch up by the middle
of the 21st century. Between 2010 and 2050, the world’s total population is
expected to rise to 9.3 billion, a 35% increase.1 Over that
same period, Muslims – a comparatively youthful population with high fertility
rates – are projected to increase by 73%. The number of Christians also is
projected to rise, but more slowly, at about the same rate (35%) as the global
population overall.
As a
result, according to the Pew Research projections, by 2050 there will be near
parity between Muslims (2.8 billion, or 30% of the population) and Christians
(2.9 billion, or 31%), possibly for the first time in history.2
With the
exception of Buddhists, all of the world’s major religious groups are poised
for at least some growth in absolute numbers in the coming decades. The global
Buddhist population is expected to be fairly stable because of low fertility
rates and aging populations in countries such as China, Thailand and Japan.
Worldwide,
the Hindu population is projected to rise by 34%, from a little over 1 billion
to nearly 1.4 billion, roughly keeping pace with overall population growth.
Jews, the smallest religious group for which separate projections were made,
are expected to grow 16%, from a little less than 14 million in 2010 to 16.1
million worldwide in 2050.
Adherents
of various folk religions – including African traditional religions, Chinese
folk religions, Native American religions and Australian aboriginal religions –
are projected to increase by 11%, from 405 million to nearly 450 million.
And all
other religions combined – an umbrella category that includes Baha’is, Jains,
Sikhs, Taoists and many smaller faiths – are projected to increase 6%, from a
total of approximately 58 million to more than 61 million over the same period.3
While
growing in absolute size, however, folk religions, Judaism and “other
religions” (the umbrella category considered as a whole) will not keep pace
with global population growth. Each of these groups is projected to make up a
smaller percentage of the world’s population in 2050 than it did in 2010.4
Similarly,
the religiously unaffiliated population is projected to shrink as a percentage
of the global population, even though it will increase in absolute number. In
2010, censuses and surveys indicate, there were about 1.1 billion atheists,
agnostics and people who do not identify with any particular religion.5 By 2050,
the unaffiliated population is expected to exceed 1.2 billion. But, as a share
of all the people in the world, those with no religious affiliation are
projected to decline from 16% in 2010 to 13% by the middle of this century.
At the
same time, however, the unaffiliated are expected to continue to increase as a
share of the population in much of Europe and North America. In the United
States, for example, the unaffiliated are projected to grow from an estimated
16% of the total population (including children) in 2010 to 26% in 2050.
As the
example of the unaffiliated shows, there will be vivid geographic differences
in patterns of religious growth in the coming decades. One of the main
determinants of that future growth is where each group is geographically
concentrated today. Religions with many adherents in developing countries –
where birth rates are high, and infant mortality rates generally have been
falling – are likely to grow quickly. Much of the worldwide growth of Islam and
Christianity, for example, is expected to take place in sub-Saharan Africa. Today’s
religiously unaffiliated population, by contrast, is heavily concentrated in
places with low fertility and aging populations, such as Europe, North America,
China and Japan.
Globally,
Muslims have the highest fertility rate, an average of 3.1 children per woman –
well above replacement level (2.1), the minimum typically needed to maintain a
stable population.6
Christians are second, at 2.7 children per woman. Hindu fertility (2.4) is
similar to the global average (2.5). Worldwide, Jewish fertility (2.3 children
per woman) also is above replacement level. All the other groups have fertility
levels too low to sustain their populations: folk religions (1.8 children per
woman), other religions (1.7), the unaffiliated (1.7) and Buddhists (1.6).
Another
important determinant of growth is the current age distribution of each
religious group – whether its adherents are predominantly young, with their
prime childbearing years still ahead, or older and largely past their
childbearing years.
In 2010,
more than a quarter of the world’s total population (27%) was under the age of
15. But an even higher percentage of Muslims (34%) and Hindus (30%) were
younger than 15, while the share of Christians under 15 matched the global
average (27%). These bulging youth populations are among the reasons that
Muslims are projected to grow faster than the world’s overall population and
that Hindus and Christians are projected to roughly keep pace with worldwide
population growth.
All the
remaining groups have smaller-than-average youth populations, and many of them
have disproportionately large numbers of adherents over the age of 59. For
example, 11% of the world’s population was at least 60 years old in 2010. But
fully 20% of Jews around the world are 60 or older, as are 15% of Buddhists,
14% of Christians, 14% of adherents of other religions (taken as a whole), 13%
of the unaffiliated and 11% of adherents of folk religions. By contrast, just
7% of Muslims and 8% of Hindus are in this oldest age category.