Benefits of Increased Carbon Dioxide (CO2)

Benefits of Increased Carbon Dioxide (CO2)

Carbon dioxide occurs naturally in the environment and plants need carbon dioxide to grow. By increasing the ambient CO2 (Carbon Dioxide) levels in an environment, it is possible to increase the growth and improve the overall health of many plants. Here’s why:


Photosynthesis is the process by which green plants utilize the sun’s energy to convert carbon dioxide and water into food energy (sugars and starches). Carbon dioxide is produced naturally by animals during respiration (the normal process of breathing) and absorbed by plants during photosynthesis. Plants produce oxygen, animals inhale air (which contains oxygen) and exhale carbon dioxide, and the cycle repeats. The naturally occurring level of CO2 averages around 400 ppm (parts per million) or 0.04%.

Some specific benefits of increasing the CO2 concentration in the growing environment include:

  • Growth. Boost plant’s rate of growth often from the first day. This “head start” can mean improved productivity in later stages of the plant’s development.
  • Size. Observations have shown that doubling the concentration of CO2 in an environment increases the total weight of herbaceous plants by 30 to 50%
  • Roots. With increased CO2, plants produce more fine roots, the key to obtaining nutrients and water from the soil
  • Flowers. Increase the number and size of flowers
  • Light. Decrease the intensity of light required for growth
  • Temperature. Increase optimum growing temperature
  • Air & Water. The size and number of stomatal apertures (pores) decreases. This reduces absorption of air pollutants that would result in lower yields. It also decreases the amount of moisture lost through evaporation
  • Toxicity. Improve the ability to contend with toxic elements in the soil
  • Pests. Increase the production of defense compounds
  • Time. Crops reach maturity faster
  • Yield. The bottom line. Crop yields increase as the concentration of CO2 increases: roughly 30% gain with a 300ppm increase in the CO2 level

Too much of a good thing

Plants. As with most things, there is a point after which increases in the CO2 concentration will not have any beneficial effects. Current field research has shown the optimum CO2 level for greenhouse growing is between 1000 and 2000 ppm (0.1% and 0.2% respectively).

People. Very high levels of CO2 can have an adverse effect on people. Exposure to levels of 10,000 ppm (1%) can be extremely harmful. Even lower levels of CO2 can have side effects such as headaches if you are exposed to them for extended periods of time. Ensure that the normal operating level does not exceed 3,000 ppm CO2.