This is a classic debate between scientists and theologians.
I'm personally 100% on the science side of this. Scientific advancement is a good thing, as people have said, it can lead to curing diseases. This particular example, of intaking carbon dioxide and excreting biofuel, is wonderfully inventive and I wish that guy all the luck in succeeding with it.
It actually kind of pisses me off when someone who knows nothing about the field or what is done in the laboratories comes out and says, "You can't do that! It's against my religion." Because, at the core of this, it is a religious debate. Sure, there are the ideas of bio-terror and things going horribly wrong, but that's what science does: poses problems and tries to solve them. You can not advance without risk, and who wants to live in a purified bubble?
As for ethics, I've always believed it stints scientific growth, because ethics are relative. It's unfair how scientists are demonized in movies and fiction (and in real life, for that matter!). Whenever some outbreak occurs, or some supernatural entity comes into our world (ala The Mist), it's always the scientist's fault. :P
We have a barrier between science and religion for a reason:
If the Vatican truly had its way, all us scientists would be burned at the stake.