There are more Christians in the world today than people of any other religious affiliation — including no affiliation (i.e., “nones”). In the near future this will continue, as today more babies are born to Christians than those of other religious affiliations. But great changes are likely ahead, according to a new study from the Pew Research Center’s demographers entitled “The Changing Global Religious Landscape.”
Predicting the future is never easy, but demographers can use data about births and deaths to understand what populations might look like in the next few decades.
One general trend affecting the future is that people are generally living longer and having fewer children. The 21st century began with the world moving past “peak childhood,” that is, the world with the highest population of children it will ever have. Generally the number of births each year is similar to the year before and are expected to diminish over time.
In the 1960s, the average woman in the world would have five children over the course of her lifetime. She would need to have two to replace herself and her male partner in the population. When this fertility rate falls below two, on average, a population will begin to decline over time. Today, the global fertility rate is 2.5. At the same time, average life expectancy has increased from 52 in 1960 to about 71 today. Population growth is driven more now by improvements to health than by any emerging baby boom.
Regions and religion
Pew researchers have previously documented that the global Catholic population grew from about 291 million in 1910 to about 1.1 billion in 2010. Historically, Catholics have made up about half of the total world Christian population. The Pew study estimates that the number of Christians in the world will increase from 2.28 billion now to about 3.05 billion in 2060, which is an increase of 34 percent. Catholics, if they remain about half of this population, will number 1.53 billion, adding about 390 million by 2060.
Growth in the Christian population will not occur evenly across the globe. Growth will likely be slow to nonexistent in Europe, the United States and some Asian countries due to growth in the religiously unaffiliated and sub-replacement rate birth rates. Pew expects the strongest growth in the number of Christians to occur in sub-Saharan Africa. The report concludes that “the share of Christians worldwide who live in sub-Saharan Africa is expected to increase dramatically between 2015 and 2060,” from 26 percent to 42 percent, due to high fertility.
In contrast, the United States is likely to see a boom in the religiously unaffiliated. Although this population is less likely than the religiously affiliated to have children, their growth is driven in the developed world by “religious switching” with some of the religiously affiliated losing their faith. By 2060, nearly one in 10 of the world’s unaffiliated is expected to be living in the United States. This will happen even as Pew concludes that “religious nones ... are projected to decline as a share of the world’s population in the coming decades” due to low birth rates. Many of the unaffiliated of the future come into the world as Christians. The Pew report estimates, “Between 2015 and 2020, Christians are projected to experience the largest losses due to switching.” Thus, even though nones will become a smaller share of the world’s population, they are still expected to grow in absolute numbers from 1.17 billion now to 1.2 billion in 2060.
Church shifts globally
How will the Catholic Church adapt to these emerging demographic realities? It will likely look to evangelization efforts that bring some former Catholics back to the Faith in the developed world. If they return, the brick and mortar will still likely be there to serve the faithful. But declining populations are likely to translate into declining numbers of vocations and resources. In the United States, the Church has come to rely on some priests and religious from the developing world to serve in parish ministry. In the future these clergy and religious are more likely to be needed in the country of their birth — especially in Africa.
Globally today there is a total population of Catholic priests, deacons and vowed religious of 1.2 million to serve a population of about 1.2 billion. That is essentially a ratio of one per 1,000. If the Catholic population is 1.53 billion in 2060 it will need to increase its clergy and vowed religious workforce by 330,000. It will also need to consider how this workforce is distributed around the world. In addition to new vocations the Church will need new brick and mortar. In Europe today there are 2,373 Catholics and 1.5 priests per parish. In Africa there are 13,469 Catholics and 2.7 priests per parish. This disproportionality will likely continue to grow in the broader trends projected by Pew researchers.
From 2010-15 in sub-Saharan Africa, Christian births outnumbered deaths by 64.5 million. In Europe during the same time Christian deaths exceeded births by 5.6 million. From 2055-60 Christian births in sub-Saharan Africa are still expected to exceed Christian deaths by 79 million. Christian deaths in Europe at the same time are expected to outpace Christian births by 12 million.
The global Catholic population went through one of its most extraordinary realignments in the 20th century — shifting from a predominantly European-centered church to a global church. In the 21st century it will shift even further away from Europe. This won’t happen through migration but by simple life choices about family life and children. With this shift, the Church faces significant challenges in maintaining what it has built in Europe and other developed countries while building a new infrastructure in the global south, especially in Africa.
Mark M. Gray, Ph.D., is a senior research associate for the Center for Applied Research in the Apostolate at Georgetown University.