Irreligion may include some forms of theism, depending on the religious context it is defined against; for example, in 18th-century Europe, the epitome of irreligion was deism. According to Pew Research Center projections, the non-religious, though temporarily increasing, will ultimately decline significantly by 2050 because of lower reproductive rates and ageing.
In 1993, the UN's human rights committee declared that article 18 of the International Covenant on Civil and Political Rights "protects theistic, non-theistic and atheistic beliefs, as well as the right not to profess any religion or belief." The committee further stated that "the freedom to have or to adopt a religion or belief necessarily entails the freedom to choose a religion or belief, including the right to replace one's current religion or belief with another or to adopt atheistic views." Signatories to the convention are barred from "the use of threat of physical force or penal sanctions to compel believers or non-believers" to recant their beliefs or convert.
Most Western democracies protect the freedom of religion, and it is largely implied in respective legal systems that those who do not believe or observe any religion are allowed freedom of thought.
A noted exception to ambiguity, explicitly allowing non-religion, is Article 36 of the Constitution of the People's Republic of China (as authored in 1982), which states that "No state organ, public organization or individual may compel citizens to believe in, or not to believe in, any religion; nor may they discriminate against citizens who believe in, or do not believe in, any religion." Article 46 of China’s 1978 Constitution was even more explicit, stating that "Citizens enjoy freedom to believe in religion and freedom not to believe in religion and to propagate atheism."
Although 11 countries listed below have non-religious majorities, it does not mean that the majority of the populations of these countries don′t belong to any religious group. For example, 67.5% of the Swedish population belongs to the Lutheran Christian Church, while 58.7% of Albanians declare themselves as Muslims. Also, though Scandinavian countries have among the highest measures of nonreligiosity and even atheism in Europe, 47% of atheists who live in those countries are still members of the national churches.
A Pew 2015 global projection study for religion and nonreligion, projects that between 2010 and 2050, there will be some initial increases of the unaffiliated followed by a decline by 2050 due to lower global fertility rates among this demographic. Sociologist Phil Zuckerman's global studies on atheism have indicated that global atheism may be in decline due to irreligious countries having the lowest birth rates in the world and religious countries having higher birth rates in general.
According to Pew Research Center's 2012 global study of 230 countries and territories, 16% of the world's population is not affiliated with a religion, while 84% are affiliated. A 2012 WIN/Gallup International report on a poll from 57 countries reported that 59% of the world's population identified as religious, 23% as not religious, 13% as "convinced atheists", and also a 9% decrease in identification as "religious" when compared to the 2005 average from 39 countries. Their follow-up 2015 report on another wave of polling found that 63% of the globe identified as religious, 22% as not religious, and 11% as "convinced atheists". However, other researchers have advised caution with the WIN/Gallup International figures since other surveys which use the same wording, have conducted many waves for decades, and have a bigger sample size, such as World Values Survey; have consistently reached lower figures for the number of atheists worldwide.
Being non-religious is not necessarily equivalent to being an atheist or agnostic. Pew Research Center's global study from 2012 noted that many of the nonreligious actually have some religious beliefs. For example, they observed that "belief in God or a higher power is shared by 7% of Chinese unaffiliated adults, 30% of French unaffiliated adults and 68% of unaffiliated U.S. adults." Out of the global nonreligious population, 76% reside in Asia and the Pacific, while the remainder reside in Europe (12%), North America (5%), Latin America and the Caribbean (4%), sub-Saharan Africa (2%) and the Middle East and North Africa (less than 1%).
The term nones is sometimes used in the U.S. to refer to those who are unaffiliated with any organized religion. This use derives from surveys of religious affiliation, in which "None" (or "None of the above") is typically the last choice. Since this status refers to lack of organizational affiliation rather than lack of personal belief, it is a more specific concept than irreligion. A 2015 Gallup poll concluded that in the U.S. "nones" were the only "religious" group that growing as a percentage of the population.
The tables below order the percentage of a country's population that are non-religious from highest to lowest:-
Percentage of population
that is non-religious (>20%)
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^Earth Versus the Science-fiction Filmmakers - Page 70, Tom Weaver - 2005
^Zoroastrianism: An Introduction - Page 227, Jenny Rose - 2011
^Resourcewomen (2000). Religious Funding Resource Guide. p. 439.
^Mammone, Andrea (2013). Varieties of Right-Wing Extremism in Europe.
^Models for Christian Higher Education, Richard Thomas Hughes, William B. Adrian - 1997, p 403
^Pollack, Kenneth (2014). Unthinkable: Iran, the Bomb, and American Strategy. p. 29. Although many Iranian hardliners are Shi'a chauvinists, Khomeini's ideology saw the revolution as pan-Islamist, and therefore embracing Sunni, Shi'a, Sufi, and other, more nondenominational Muslims
^Continuity and Change, Steven T. Katz, Steven Bayme - 2012, p 268
^Personality Of Adolescent Students - Page 42, D.B. Rao - 2008
^The Buddhist Experience in America - Page 147, Diane Morgan - 2004
^Wiccan Warrior: Walking a Spiritual Path in a Sometimes Hostile World - Page 173, Kerr Cuhulain - 2000
^Keysar, Ariela; Navarro-Rivera, Juhem (2017). "36. A World of Atheism: Global Demographics". In Bullivant, Stephen; Ruse, Michael. The Oxford Handbook of Atheism. Oxford University Press. ISBN0199644659.