The 3rd Biggest Religion on the Planet: None

A new study from the Pew Research Center provides a global snapshot of religious change between 2010 and 2020, showing Muslims as the fastest-growing faith group, followed by people with no religious affiliation. The standout findings:

• The world's Muslim population rose by 347 million over the decade—that's "more than all the other religions combined," notes NPR—largely due to higher birth rates, especially in the Middle East-North Africa and sub-Saharan Africa, and in the Asia-Pacific region. It's the second largest religious group globally, accounting for 25.6% of the population.
• Senior Pew demographer Conrad Hackett emphasizes the driving factor: "Muslims are having children at a greater number than Muslims are dying. Very little of the change in Muslim population size is a result of people becoming Muslim as adults or leaving Islam as adults."

• Christianity remains the world's biggest religion with 2.3 billion adherents (28.8% of the global population). It grew by 122 million people over the 10-year period, but its overall slice of the pie shrank by 1.8%.
• Some of that is due to more people becoming religiously unaffiliated—that group grew a full percentage point to 24.2% and is now the third largest, with Hindus fourth at 14.9%. The "nones" gained ground in North America, where the unaffiliated jumped 13 percentage points to 30.2% of the population; nones account for 25.3% of Europe's population and 78% of those in the Asia-Pacific region.
• Buddhism was the only religion to see a decline over the 10-year period, with its count dropping by 19 million people.
• The smallest religious group analyzed by the report was Judaism. The world's Jewish population grew by 6%, from about 14 million to 15 million people; that makes up 0.2% of the global population.