And you really need that birth certificate? Can't they maybe give you a temporary passport with another kind of id? Or couldn't they maybe fax the certificate to the passport-people to hurry things up?

In any case I would try and beg and plead. In my experience the authorities can be really quick when they want to be. And begging and pleading sometimes works.

Damn. This would have been so me. Luckily I didn't need a birth certificate and luckily in Germany you can get a temporary passport which only takes a few days or else I would never have made it to Mongolia either.