Muslims Set to Become Largest Faith Group by 2075

  • July 28, 2017
  • by David O'Reilly

The number of American Muslims is a very emotionally driven issue. Amaney Jamal, Princeton University

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 sub-Saharan 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 Pew-Templeton 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).

Trust Magazine Summer 2017

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 19th-century 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 Pew-Templeton 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-to-face 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 Hackett, further emphasizing Islam’s growing numbers in the decades to come. Its opening paragraph notes that worldwide, “more babies were born to Christian mothers than to members of any other religion in recent years, reflecting Christianity’s continued status as the world’s largest religious group. But this is unlikely to be the case for much longer: Less than 20 years from now, the number of babies born to Muslims is expected to modestly exceed births to Christians.” Muslims’ high birth rates and relatively young population led the researchers to project that between 2030 and 2035, there will be 225 million children born to Muslim mothers, compared with 224 million to Christians.

Trust Magazine Summer 2017

Jalda, a Muslim from Afghanistan, sits with her friends Doreen, Liliana and Marlene at an ice cream parlour in Hamburg, Germany. (© fotogloria/LUZ/redux)

Among the report’s other population forecasts is that the number of Christians will rise by 34 percent by 2060, slightly faster that the overall global growth rate but just half that of Muslims. And that, except for Muslims and Christians, followers of all major world religions—including Hindus, Buddhists, Jews, and adherents of folk religions—are projected to make up a smaller percentage of the global population in 2060 than they did in 2015.

Still another key finding is that the proportion of people who don’t claim any religion—the “nones”—is expected to decline from 16 percent of the world’s population to 13 percent (even though their numbers are rising in the United States). By about 2060, just 9 percent of all babies will be born to religiously unaffiliated women, while more than 70 percent will be born to either Muslims (36 percent) or Christians (35 percent), according to the projections.

The center’s rich data and detailed analyses, along with the thorough explanations of methodology that accompany its major reports, have created a transparent body of religion research that has become a valuable source to government leaders, scholars, and policymakers. CIA spokesman Jonathan Liu says the Pew Research Center “has contributed a great deal to recent scholarship on the estimated and projected size and distribution of the world’s major religions.” Center studies are among the sources the agency uses to compile its World Factbook of statistical data on all the world’s countries, which is a standard reference for many in foreign policy fields. And “for some countries,” says Liu, the World Factbook “uses Pew estimates as the sole source.”

Scholars say the center’s work avoids bias or political agenda. “It is quite excellent that the Pew surveys … have resisted pressure from [religious] activists” to accept their sometimes inflated figures, says Khalid Y. Blankinship, an authority on Islamic demographics at Temple University. Still, there are religious advocates who believe their numbers are larger than the center’s estimates. Many recent Muslim immigrants “are not accessible to traditional head counting,” contends Ibrahim Hooper, spokesman for the Council on American-Islamic Relations (CAIR), based in Washington, D.C. Contrary to Pew’s 2015 estimate of 3.3 million Muslims in the United States, he says, “our best guess is 6.7 million.”

That figure comes from the research of Ihsan Bagby, associate professor of Islamic studies at the University of Kentucky, whose 2001 and 2011 U.S. Mosque Surveys were funded by the Hartford Institute for Religion Research and several Muslim organizations, including CAIR. Still, Bagby himself says, “I think Muslim scholars respect what Pew has done, and respect its integrity.”

Pew’s estimate of 3.3 million Muslims in the United States is based on a combination of immigration data and national polling, including a 2011 Pew survey of Muslim Americans, conducted on cellphones and landlines in Arabic, Farsi, and Urdu as well as in English. Pew is now conducting another major survey of U.S. Muslims, which will yield an updated population estimate later this year.

“Because the U.S. census does not count the size of religious groups, we try to fill the information void with well-grounded estimates,” says Besheer Mohamed, who wrote his doctoral dissertation at the University of Chicago on Pew’s first survey of Muslim Americans, conducted in 2007. He is now a senior researcher at the Pew Research Center, managing the new survey. “There may be some people who will never be happy, no matter what number we come up with. But we explain our methodology, document the extensive efforts we take to reach Muslims in our polls, and make the data public. And that’s really all we can do.”

The number of American Muslims “is a very emotionally driven issue,” notes Amaney Jamal, Edwards Sanford Professor of Politics at Princeton University and principal co-investigator of the Arab Barometer Project, which since 2005 has surveyed the politically relevant attitudes of citizens in the Arab world. “But Pew is seen as being very committed to getting its numbers right—that it doesn’t `have a dog in the fight,’ as they say.”

The Sept. 11 attacks were a turning point in modern relations between Islam and the West, says Jamal, and did much to propel today’s high level of interest in the attitudes and demography of the world’s Muslims. “Until then, we [in the West] tended to treat Muslims and the Arab world as this big, monolithic lump with very little detailed, contextually based knowledge that distinguished Iran from Saudi Arabia, or Morocco from Indonesia.”

Detailed, agenda-free, methodologically sound demographic and attitude surveys of Islam not only help governments “design better policies to address radicalism or extremism or anti-westernism,” she says, but also help break down stereotypes and mutual suspicions and reveal cross-cultural commonalities. A 2011 Pew survey found, for example, that 69 percent of U.S. Muslims say religion is very important in their lives, virtually the same as 70 percent of U.S. Christians.

“Pew has really become a state-of-the-art research hub,” says Jamal. “When it conducts meaningful research on the Muslim and Arab worlds, people pay a lot of attention.”