Under the following conditions, C4 plants are superior to C3 plants: Even at low CO₂ levels, C4 plants can carry out photosynthesis. At approximately 360 L-1, C4 plants show saturation whereas C3 plants show only after 450 L-1 saturation. The availability of CO₂ is therefore a limited factor for C3 plants; not C4 plants.

C4 plants have a higher optimum temperature, but C3 plants have a lower optimum temperature. Therefore, even at high temperatures, C4 plants can perform photosynthesis; this is not the case with C3 plants.

Because of Kranz anatomy, C4 plant is not affected by high levels of oxygen in the atmosphere. Kranz anatomy ensures that photorespiration in C4 plants is not carried out. But with C3 plants, this is not the case.