The study explores how plants have evolved to cope with rising CO2 levels and changing climates. It shows that C4 plants have developed a more efficient way of photosynthesis compared to C3 plants, by concentrating CO2 around the enzyme RuBisCO. This helps reduce a process called photorespiration, which can waste energy. The research suggests that C4 plants evolved from C3 plants with lower enzyme specificity, allowing them to adapt to higher CO2 levels. On the other hand, some C3 plants with higher enzyme specificity can thrive in stressful environments. Overall, the study indicates that RuBisCO has the flexibility to adapt to different environmental conditions to ensure efficient photosynthesis.