Not quite, roger. Trees break down the CO2 into oxygen and glucose. It doesn't produce carbon directly.
The equation for photosynthesis is:
6(CO2) + 6(H2O) ---------------> C6H12O6 + 6(O2)
Hi Mollykins- do you mean photosynthesis takes a lot of energy (yes it needs some light energy) or are you referring to splitting C0₂into oxygen and carbon (yes, that certainly needs a lot of energy)?