I waited for a Catholic source before posting. This is all over the internet.
Here are the Pope's actual words. The words "heaven", "salvation", and "saved" don't even appear in the text. How anyone could conclude from this that Pope thinks atheists can work their way to heaven ... beats me.
He's not the theologian BXVI was, I'll grant you, but give the man a little credit: he knows what Pelagianism is, and why it's wrong.