Carbon dioxide fertilization involves enriching greenhouse atmospheres with additional CO2 to boost plant growth and crop yields. Higher CO2 levels shift the activity of the enzyme rubisco to favor carbon fixation, leading to an average 33% increase in yields with a doubling of CO2 concentration. Commercial greenhouse operations commonly maintain CO2 levels between 1000 ppm for sunny conditions to 700 ppm for young plants or cloudy days to maximize photosynthesis and growth while minimizing ventilation needs. In addition to increased yields, higher CO2 can improve fruit sugar content, reduce acid levels, and enhance taste, growth rates, and time to flowering for some ornamental crops.