Why is there green crap on the roof?

You've seen it




http://www.chron.com/cs/CDA/ssistory.mpl/topstory/2134382


But why the hell is it there?

At first it was. Who is going to pay to fix it?

Now the maker has offered to clean it for free.

But the Astros are wondering, maybe the mold is eating the roof itself? Or Perhaps the glue used in the roofing material?

Then cleaning would not really solve the problem then, would it?

But our favorite mis-managed team might be left with looking like dumb asses if the mold is only there because of the temperature difference between the cooler inside against the hot outside creating condensation or they are just eating off the damn pollution settling on the roof?

So what do you think ?