The Pope said ahead of his first tour of Africa last month that condoms were not a solution for Aids and could even make the problem worse. His comments faced a barrage of criticism from leftist, gay and Aids activist groups.
Dawkins said the comments demonstrated that the Pope "is either stupid, ignorant or just dim”.
Speaking at the University of Valencia, where he had just been awarded an honourary degree, Dawkins claimed that the Pope would have the blood of thousands or even millions of people on his hands if people took his words seriously.
Despite the criticism laid on the Pope by Dawkins and others, a number of other experts have come out in favour of the Pope’s stance on contraception, such as Edward C Green, the director of the Aids Prevention Research Project at Havard.
Dawkins also used his speech to praise US President Barack Obama for overturning a funding ban on stem cell research.
Dawkins, who wrote the bestselling book “The God Delusion”, claimed that people were less likely to believe in God the more they thought for themselves. Earlier this year he was a prominent supporter of an atheist bus campaign which claimed, “There’s probably no God. Now stop worrying and enjoy your life.”