[SgtSolomon]

Funny thing is, as far as I can remember (I hope I'm not labeling myself an ignorant moron), trees actually produce CO2 during the day, and only produce oxygen at night.

No, wait, that can't be - George Bush must've told the American People that one. Yeah, that's where I got it.

[SgtSolomon]

Ok, correction: plants produce CO2 at night, oxygen during the day. See, it ~was~ one of Dubya's lies to the American People. *shifty eyes*

[Old Professer]

The oxygen that trees emit comes from the water their roots take up; obviously some trees are more efficient than others at this and all are poor substitutes for ocean plankton; as leaves decompose every fall and dead branches fall and rot the carbon is given back to the atmosphere.

Many trees are net polluters, terpenes, isoprenes of all sorts.