Christians will be outnumbered by Muslims by 2035 as birth rates in Islamic countries outstrip those in the west, according to a new demographic analysis.

In recent years, more babies were born to Christian mothers than to members of any other religion, reflecting Christianity’s continued status as the world’s largest religious group.

But according to Washington-based think tank The Pew Research Centre, this is unlikely to be the case into the future.

Less than 20 years from now, the number of babies born to Muslims is expected to modestly exceed births to Christians, according to the Pew research.

Muslims are projected to be the world’s fastest-growing major religious group in the decades ahead and signs of this rapid growth already are already visible.

Between 2010 and 2015, births to Muslims made up an estimated 31 per cent of all babies born around the world – far exceeding the Muslim share of people of all ages in 2015 which is around 24 per cent.

The world’s Christian population also has continued to grow, but more modestly. In recent years, 33 per cent of the world’s babies were born to Christians, which is slightly greater than the Christian share of the world’s population in 2015 at 31 per cent.

While the relatively young Christian population of a region like sub-Saharan Africa is projected to grow in the decades ahead, the same cannot be said for Christian populations everywhere.

And Christians have had a disproportionately large share of the world’s deaths at 37 per cent, according to the Pew Center.

This is because of the comparatively advanced age of Christian populations in some places, especially in Europe, where the number of deaths already is estimated to exceed the number of births among Christians.

In Germany, for instance, there were an estimated 1.4 million more Christian deaths than births between 2010 and 2015, a pattern that is expected to continue across much of Europe in the years ahead.

“Globally, the relatively young population and high fertility rates of Muslims lead to a projection that between 2030 and 2035, there will be slightly more babies born to Muslims (225 million) than to Christians (224 million), even though the total Christian population will still be larger,” the Pew Center report said.

“By the 2055 to 2060 period, the birth gap between the two groups is expected to approach 6 million – 232 million births among Muslims versus 226 million births among Christians,” the report said.

“In contrast with this baby boom among Muslims, people who do not identify with any religion are experiencing a much different trend. While religiously unaffiliated people currently make up 16 per cent of the global population, only an estimated 10 per cent of the world’s newborns between 2010 and 2015 were born to religiously unaffiliated mothers,” it said.

The report said this dearth of newborns among the unaffiliated helps explain why numbers of non-religious people are projected to decline as a share of the world’s population in the coming decades.

By 2055 to 2060, just 9 per cent of all babies will be born to religiously unaffiliated women, while more than seven-in-ten will be born to either Muslims (36 per cent) or Christians (35 per cent).

The report said Christians were the largest religious group in the world in 2015, making up nearly a third (31 per cent) of Earth’s 7.3 billion people. Muslims were second, with 1.8 billion people, or 24 per cent of the global population, followed by non-religious (16 per cent), Hindus (15 per cent) and Buddhists (7 per cent).

It said adherents of folk religions, Jews and members of other religions make up smaller shares of the world’s people.

Between 2015 and 2060, the world’s population is expected to increase by 32 per c dent, to 9.6 billion. Over that same period, the number of Muslims – the major religious group with the youngest population and the highest fertility – is projected to increase by 70 per cent.

The number of Christians is projected to rise by 34 per cent, slightly faster than the global population overall yet far more slowly than Muslims.

Except for Muslims and Christians, all major world religions are projected to make up a smaller percentage of the global population in 2060 than they did in 2015.

While Hindus, Jews and adherents of folk religions are expected to grow in absolute numbers in the coming decades, none of these groups will keep pace with global population growth.

Worldwide, the number of Hindus is projected to rise by 27 per cent, from 1.1 billion to 1.4 billion, lagging slightly behind the pace of overall population growth. Jews, the smallest religious group for which separate projections were made, are expected to grow by 15 per cent, from 14.3 million in 2015 to 16.4 million worldwide in 2060.

And adherents of various folk religions – including African traditional religions, Chinese folk religions, Native American religions and Australian aboriginal religions, among others – are projected to increase by 5 per cent, from 418 million to 441 million.

Buddhists, meanwhile, are projected to decline in absolute number, dropping 7 per cent from nearly 500 million in 2015 to 462 million in 2060. Low fertility rates and aging populations in countries such as China, Thailand and Japan are the main demographic reasons for the expected shrinkage in the Buddhist population in the years ahead.

All other religions combined – an umbrella category that includes Baha’is, Jains, Sikhs, Taoists and many smaller faiths – also are projected to decrease slightly in number, from a total of approximately 59.7 million in 2015 to 59.4 million in 2060.

The religiously unaffiliated population is projected to shrink as a percentage of the global population, even though it will increase modestly in absolute number.

Laurie Nowell
AMES Australia Senior Journalist