Is CO2 a pollutant? What do the experts say?

“Carbon and CO2 (carbon dioxide) are fundamental for all life on Earth. CO2 is a colorless, odorless, non-toxic gas. CO2 is product of our breathing, and is used in numerous common applications like fire extinguishers, baking soda, carbonated drinks, life jackets, cooling agent, etc. Plants’ photosynthesis consume CO2 from the air when the plants make their carbohydrates, which bring the CO2 back to the air again when the plants rot or are being burned.” - Tom V. Segalstad, Ph.D. Professor of Environmental Geology, University of Oslo




“CO2 is not a pollutant. In simple terms, CO2 is plant food. The green world we see around us would disappear if not for atmospheric CO2. These plants largely evolved at a time when the atmospheric CO2 concentration was many times what it is today. Indeed, numerous studies indicate the present biosphere is being invigorated by the human-induced rise of CO2. In and of itself, therefore, the increasing concentration of CO2 does not pose a toxic risk to the planet.” - John R. Christy, Ph.D. Professor of Atmospheric Sciences, University of Alabama



“Atmospheric CO2 is required for life by both plants and animals. It is the sole source of carbon in all of the protein, carbohydrate, fat, and other organic molecules of which living things are constructed. Plants extract carbon from atmospheric CO2 and are thereby fertilized. Animals obtain their carbon from plants. Without atmospheric CO2, none of the life we see on Earth would exist. Water, oxygen, and carbon dioxide are the three most important substances that make life possible. They are surely not environmental pollutants.” - Arthur B. Robinson, Ph.D. Chemistry