... has been known for decades. This has never been in doubt. And, this fact is often the centerpiece of skeptics' argument that global warming is okay.

In those parts of the world where global climate change does not invoke drought or stifling temperatures, then increased CO₂ might be beneficial. Considering the extremely negative impacts of warming oceans, the net result won't be positive.

Rising CO2 levels are definitely beneficial to plants. The problem would be accompanying droughts and climate instability. Higher CO2 doesn't do you any good if it goes months without raining and all the plants in the area die.