In my view atheism is a belief based on rational science. Christianity and other religions are beliefs not based on rational science.

Dawkins, being a scientist, would have to change his position if he was presented with good new evidence - in this sense he does remain open-minded. But at present there is no known compelling scientific evidence for the existence of 'god,' and it seems *extremely* unlikely that such evidence will be found any time soon (it would literally take a miracle for this to happen). So the rational way forward is to believe in the non-existence of god. Atheists are not blind to the possibility of future evidence, they simply believe that it is irrational to expect such evidence to ever turn up.