From Matt Wade in The Age
During my lifetime, the share of Australians without a religious affiliation has gone from one in 100 to about one in three.
That's what you call a momentous social change.
The latest census data has been collected and analysed. Here's a snapshot of Australia shown as a group of 100 people.
The spike in people opting for "no religion" was one of the big stories to come out of the 2016 census results released in June. More than 7 million Australians said they have no religious affiliation, a 46 per cent increase on the previous census in 2011.
Given that trend, you might expect the share of the world's population with no religion is also on the rise.
The experience of Western, Christian-majority countries is not necessarily the global experience.
Most Americans think so. A recent US poll found 62 per cent of respondents believe the share of people with no religion will increase between now and 2050. My guess is the share in Australians making that assumption would be even higher.
But long-term population projections by the Washington-based Pew Research Centre show the global reality is quite different to what's going on in Australia and other Western nations.
"The experience of Western, Christian-majority countries is not necessarily the global experience," said Conrad Hackett, a senior demographer with Pew Research who visited Australia last week.
"There was perhaps this sense in the 1960s that religion might be on its way to extinction … but that just hasn't played out."
Pew's report says about one in six of the world's people now has no religious affiliation. But that's forecast to shrink to just one in eight of the global population by 2060.
Why? Because those who opt for "no religion" on their census forms are heavily concentrated in places with ageing populations and low fertility, such as China, Japan, Europe, North America and Australia. The majority of the world's "religiously unaffiliated" are in China (61 per cent) and Japan.
By contrast, populations in places with many religious adherents – mostly developing countries where birth rates are high and infant mortality rates have been falling – are likely to grow strongly. Much of the worldwide growth of Islam and Christianity, for example, is expected to take place in sub-Saharan Africa.
The trend for people to switch to "no religion" in Western nations like Australia is likely to continue, mostly at the expense of traditional Christian denominations. But that won't be nearly enough to offset population growth in places where people are still happy to be affiliated with a religious faith.
The Pew report describes this as the "demographic challenges of the religiously unaffiliated".
Between 2015 and 2020, the total fertility rate for women with no religion is projected to be 1.6 children per woman while the rate among women with a religious affiliation is forecast to be 2.5 children per women.
Pew estimates the world's "no religion" ranks will grow by a paltry 3 per cent between now and 2060. That compares with projected growth of 70 per cent for Muslims, 34 per cent for Christians and 27 per cent for Hindus (the global population is forecast to grow by 32 per cent in that period).
As a result, the share of the world's population identifying with a religion is set to rise from 84 per cent to 87 per cent between now and 2060, the Pew study predicts.
Australia might be losing its religion, but the world isn't.
Example of Question 19: What is the person's Religion? (2016 Census)