A phenomena known as "carbon fertilization" may result in the increase of CO2 concentration to have positive effects on the environment. To understand how this process works, one must first have a basic understanding of the process of photosynthesis. Photosynthesis is by far the most important chemical process on the planet. Without it, we would have no food, no oxygen, and no fossil fuels. Photosynthesis is performed mainly by higher-level plants and algae. These organisms convert carbon dioxide in the atmosphere into carbohydrates. The reaction also involves water and sunlight for energy. The reaction can be represented by the chemical equation:.
CO2 + H2O C3OH.
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Fig. 2: The carbon cycle.
Source: John W. Kimball.
The rate of photosynthesis is limited primarily by the levels of carbon dioxide present in the atmosphere (Arizona State University, 1998). Hence, increased levels of carbon dioxide will lead to an increased rate of photosynthesis and thereby, more plant growth. A study conducted by the International Union of Forestry Research Organizations found that under optimal conditions (high level of nutrients and water available) a doubling in CO2 concentration leads to a 49% increase in biomass production in many species of trees (Tektran, 1998). Other studies have attained similar results.
A higher concentration of CO2 was also found to increase drought tolerance in certain species of trees. This occurs because high CO2 concentrations cause trees to better regulate their water consumption.
While it appears that increasing CO2 concentrations will be beneficial to mankind, resulting in higher crop yields and cheaper food, it must be noted that increased photosynthesis rated occur in only some species of plants. In studies conducted by The United States Department of Agriculture Agricultural Research Service, it was found that weed species enjoyed a much higher increase in growth rates than crop species.