The biggest unknown factor, however, is China, the world’s most populous country. Because of a lack of reliable data on religious switching in China, none of the scenarios models religious switching among its 1.3 billion people. If there is considerable switching in China in the coming decades, it could lower the percentage of the world’s population that is unaffiliated and boost the numbers of Christians, Buddhists and perhaps other groups. (See
sidebar on China at the end of this chapter.)...
While it is clear that religious affiliation and practice have risen dramatically in China since the end of the Cultural Revolution, data on recent patterns of religious switching are practically nonexistent
35. Anecdotally, some newspaper articles and reports from religious groups have attempted to describe changes underway in China, but it is unclear how accurately these accounts reflect change underway at the country level.
36 Still, some experts believe that China’s Christian population is growing, perhaps rapidly. Most notably, one of the world’s leading specialists on religion in China, Purdue University sociologist Fenggang Yang, estimates that the Christian population in China grew at an
average annual rate of 7% between 1950 and 2010. At this rate, Yang calculates the proportion of China’s population that is Christian could grow from 5% in 2010 to 67% in 2050.
37
Without survey data measuring patterns of switching among China’s main religious groups, it is not possible to formally model switching in China, as this report does for other countries.
38 However, it is possible to conduct sensitivity tests that provide ballpark estimates of how much impact religious change in China could, potentially, have on the global religious landscape.
While all religious groups in China could be experiencing significant change through switching, media reports and expert assessments generally suggest that the main effects are rising numbers of Christians and declining numbers of religiously unaffiliated people. The following sensitivity tests assume, for illustrative purposes, that switching is limited to this movement between the unaffiliated and Christians.
As of 2010, China had an estimated 68 million Christians and 701 million unaffiliated people. Due primarily to differences in the age and sex composition of these initial populations, in the main projection scenario – which does not attempt to model religious switching – China’s Christian population is expected to grow slightly by 2050, to 71 million, while the unaffiliated population is expected to decline to 663 million.
Under that main scenario, 5.4% of China’s population and 31.4% of the world’s total population will be Christian in 2050. If China’s Christian population were to decline to Japanese levels (2.4% of the country’s population) in 2050, it would reduce the Christian share of the global population to 30.9%. On the other hand, if China’s Christian population was to increase to the level projected for South Korea in 2050 (33.3% of the country’s population), it would raise the count of Christians in China to 437 million and the share of Christians in the world’s overall population to 35.3%.
And if everyone who is currently unaffiliated in China were to convert to Christianity by 2050, China’s population would be 56.2% Christian (734 million Christians), raising the Christian share of the world’s population to 38.5% and lowering the unaffiliated share of the global population to 6.1%. Though that scenario may be unlikely, it offers a rough sense of how much difference religious switching in China maximally could have by 2050. Extremely rapid growth of Christianity in China could maintain or, conceivably, even increase Christianity’s current numerical advantage as the world’s largest religion, and it could significantly accelerate the projected decline by 2050 in the share of the global population that is religiously unaffiliated.