Muslims set to become largest faith group by 2075
It was not so long ago that the best attempts to convey the size and distribution of the world’s religions relied more on conjecture and rhetoric than scientific research. “Islam is today the religion of about 150 million of our fellow creatures,” the Rev. W. St. Clair Tisdall reported to the Church of England’s Missionary Society in 1892. Tisdall never said how he arrived at so very round a number. His far-flung colleagues in Africa, where British missionaries were active, might have observed more mosques than churches north of the Sahara Desert. The ratio of crescents to crosses around Africa would have been little help, though, in calculating the number of followers of each faith, let alone in projecting their growth.
Now, however, modern survey research and demographic methods can take the once murky business of calculating the size, distribution, attitudes, behavior, and likely spread of the world’s largest faiths to a degree of scientific accuracy inconceivable in the Victorian age. Two years ago, the Pew Research Center, with support from the John Templeton Foundation, not only estimated that there were 1.59 billion Muslims on the globe as of 2010, but also made front-page headlines on every continent when it projected that Islam would surpass Christianity to become the world’s largest religion by about 2075.
More recently, an April report from the center updates the estimate of the global Muslim population to 1.75 billion (as of 2015) and projects that, if current demographic trends continue, it will reach 2.99 billion by 2060. In addition to providing new data on birth and death rates in the world’s major faiths, the Changing Global Religious Landscape report reaffirms prior forecasts by the center that much of Islam’s and Christianity’s growth is “expected to take place in subSaharan Africa.” Among the new findings are these:
•Sub-Saharan Africa now contains 26 percent of the world’s Christian population but will be home to 42 percent by 2060.
•Between 2015 and 2060, the world’s population is expected to increase by 32 percent, to 9.6 billion, during which time the number of Muslims— the major religious group with the youngest population and highest birth rate—is projected to increase by 70 percent.
•In Europe today, Christians are dying in greater numbers than they are producing offspring, while the European Muslim birth rate is significantly higher than its death rate and exceeds the birth rate of any other major faith group on the continent.
The Changing Global Religious Landscape is only the latest in a series of reports produced by the PewTempleton Global Religious Futures project, an undertaking that in less than a decade has helped to transform public and professional knowledge of attitudes and demographic trends within the world’s major faith groups: Christianity, Islam, the religiously unaffiliated, Hinduism, Buddhism, Judaism, folk religions (including African traditional religions and Chinese folk religions), and other religions (a residual category that includes Baha’ism, Jainism, Sikhism, Taoism, and many smaller faiths).
Worshipers offer Tarawih, prayers performed only during the Islamic holy month of Ramadan, at the Eyup Sultan Mosque in Brooklyn, New York. (© Mohammed Elshamy/ Anadolu Agency/Getty Images)
The project began in 2010 when the foundation, based in suburban Philadelphia, partnered with the Pew Research Center on what Alan Cooperman, the center’s director of religion research, calls “an initiative to apply demographic methods and tools to the study of religion.”
There was much to be done, recalls Conrad Hackett, who joined the center as its lead demographer in 2010. “Despite all the census and survey data that was out there in all the various countries,” he says, “nobody had added up the information.”
What’s more, population data on Islam was still notoriously fuzzy even a century after Tisdall. In 1993, an American encyclopedia asserted that Islam’s worldwide population was “700 million or more”—the same year that a British almanac posited 952 million. Estimates of Canada’s Muslim population in 2001 ranged between 1 million and 6 million, with one source even proposing 12 million. Until Pew published its country-by-country estimates, many books and newspaper articles gave a ballpark figure of 1 billion Muslims worldwide.
One of the project’s first reports, Tolerance and Tension, was a landmark study of public attitudes and demographic trends in sub-Saharan Africa whose findings would have left Tisdall and his fellow 19thcentury missionaries speechless. “The number of Muslims living between the Sahara Desert and the Cape of Good Hope has increased more than 20-fold” in the past century, it reported, “rising from an estimated 11 million in 1900 to approximately 234 million in 2010.” The number of Christians has “grown even faster, soaring almost 70-fold from about 7 million to 470 million.”
In addition to its hundreds of reports and carefully researched “FactTank” blog posts on all aspects of religion, the PewTempleton Global Religious Futures project and other Pew Research Center initiatives have published more than 120 reports focused directly on Islam, or in which data on Muslims figure prominently. These have ranged from the narrowly focused to the massively comprehensive, such as the April 2013 report The World’s Muslims: Religion, Politics and Society, based on more than 38,000 face-toface interviews with Muslims in 39 countries and 80 languages.
For the Future of World Religions report in 2015, “we used 2010 as our baseline and went to the best available sources for each country to come up with religious population estimates,” explains Hackett, whose demography team spent over four years reviewing nearly 3,000 censuses, large-scale surveys, population registers, and other data sources from more than 190 nations.
April’s Changing Global Religious Landscape report represents an exhaustive reanalysis of that data, says