1. What is carbon dioxide and why is this gas an environmental concern?

Carbon dioxide is critical to life on earth. As part of the carbon cycle known as photosynthesis green plants absorb carbon dioxide, sunlight, and water to produce carbohydrate energy for themselves and oxygen as a waste product.

During respiration all living things emit carbon dioxide during respiration, which is the reverse process – the conversion of carbohydrates to energy, water and carbon dioxide.

Carbon dioxide is also naturally produced when any organic matter decomposes in the presence of oxygen.

Carbon dioxide concentrations in the atmosphere have increased over time (US Environmental Protection Agency – EPA). Carbon dioxide is a greenhouse gas, which means that it traps heat in the earth’s atmosphere. There is concern that increasing levels of greenhouse gasses in the atmosphere will lead to climate change (Intergovernmental Panel on Climate Change). Significant international effort is being made to reduce all greenhouse gasses, including carbon dioxide.