I have a great deal of admiration and respect for Julian Baggini. However, that is no reason to avoid pointing out a few errors in his "10 surprising facts about atheism." Eight of the ten are indisputably factually. The other two are not actually facts, at least not as he expresses them.
"3. Atheism is not necessarily dogmatic."
This one is misleading since it implies that atheism can be dogmatic. How? Atheism is the lack of a religious based belief system. Though, it is true that atheists as individuals can be dogmatic that is not the same thing. There is no direct causation. Individual males can be sexist. That neither means that the gender can be sexist nor that individuals of the female gender can't be sexist. Implications and conflations do not establish a "fact."
"4. Being an atheist means that you believe the balance of evidence shows that God does not exist. This is not the same as saying that you are 100% certain God does not exist."
I wish this were completely true and therefore a fact. It isn't. Many atheist I have met or interacting with in some way do fit this characterization but not all. There are atheists who lack a belief in god without ever considering the state of evidence for or against God's existence. An individual does not need to consider the "balance of evidence" for something in order to believe or disbelieve in it. Baginni is correct in pointing out the discrepancy between reasonable belief/disbelief and 100% certainty.
Both of these errors seem to hint at an all too common myth. Atheism is not an actual "ism." I understand and appreciate why some atheists want to turn it into one but that does not change the fact that by definition Atheism is not a belief system but rather the lack of a specific type of belief system.