The Pew Forum released it’s report on The Global Religious Landscape, with data pulled from a variety of different surveys taken all around the world, a few days ago. I’ve only read through the executive summary but it looks like the report contains all sorts of maps and numbers to satisfy anyone’s curiosity. According to current data, the biggest religious group is Christian (31,5%), Muslim (23,2%), unaffiliated (16,3%) and Hindus (15%). No other group had more than 10%. The unaffiliated are not necessarily atheist though as it includes people who are religious but not part of any organised religion. I’m not sure if the full report has more information on the prevalence of atheism or not but there are two projects I’m aware of that are trying to look global atheism in more detail.
The first is very basic. The Atheist Census is collecting just a tiny bit of information and counting the atheists in each country. Currently it’s counted a little over 89 000 atheists globally with the US contributing the most. Rather surprisingly, to me anyway, is that Brazil currently has the second highest number of atheists. South Africa just has 900 counted so far, though that’s more than the rest of Africa combined. Their data also shows atheists are fairly young, well-educated, male and with a Christian or irreligious background.
There’s a more detailed survey that needs participants over here which I found out about on Pharyngula. The results from that survey are not available live but there is a blog that has some information on their results. It can’t really hurt to answer the survey and just a few minutes of time will help people learn more about atheism.