Carbon Dioxide Fertilization

Through the process of photosynthesis, plants use the Sun’s energy to convert carbon dioxide and water into oxygen and energy-rich sugar molecules. Plants use sugar molecules for food and to fuel their life processes.

As carbon dioxide in the atmosphere increases, plants increase their rate of photosynthesis—a concept known as carbon dioxide fertilization. As photosynthesis increases, more carbon dioxide is removed from the atmosphere, thus lessening the increase in carbon dioxide.

Studies show that up to half of Earth’s vegetation-covered surface has increased in photosynthetic activity over the past 35 years. Scientists estimate that a significant amount of this increased photosynthetic activity can be explained by the carbon dioxide fertilization effect. However, there may be a limit to the effect that increased photosynthetic activity can have on the huge amounts of carbon dioxide released into the air by human activities.

Click to see larger version

This map shows global changes in the amount of leaf cover—leaf area per unit soil area—during the growing season. Greens represent an increase in vegetation; browns represent a decrease in vegetation.