C4 plants take ATP-expensive routes to ensure photorespiration does not occur. They minimise oxygen concentration in cells where the Krebs cycle occurs and cart carbon dioxide into these same cells. To over-simplify, they increase the carbon dioxide concentration and decrease the oxygen concentration in these cells.
Despite the ATP this costs them they are enormously successful (in hot areas at least).
Considering this, would human-caused carbon dioxide emissions, i.e. increased concentration in environmental carbon dioxide, be beneficial to plants?
Considering @Cell's comment: I mean beneficial from the 'plant's point of view', i.e. the plant can grow faster-reproduce sooner or less photorespiration occurs; due to the higher level of carbon dioxide. I think we can disregard ocean acidification for now, climate change is relavent but perhaps it could be disregarded initially? Especially as climate change effects different areas differently.
Please note: I am not encouraging or supporting human caused carbon emissions; this is a genuine question asked out of curiosity.