Carbon dioxide equivalent of carbon dioxide. Equivalent (e) is the concentration of that would cause the same level of radiative forcing as a given type and concentration of greenhouse gas. Examples of such greenhouse gases are methane, perfluorocarbons, and nitrous oxide. e is expressed as parts per million by volume, ppmv. Carbon dioxide equivalent Carbon dioxide equivalent (CDE) and equivalent carbon dioxide (e and eq) are two related but distinct measures for describing how much global warming a given type and amount of greenhouse gas may cause, using the functionally equivalent amount or concentration of carbon dioxide () as the reference. Carbon dioxide
Low-carbon diet and rail releases carbon dioxide (CO2), the primary gas responsible for global warming. Chlorofluorocarbons (CFCs) are emitted from mechanical refrigerating and freezing mechanisms – both staples in food shipment and storage. Anthropogenic methane emission sources include agriculture (ruminants, manure management, wetland rice production), various other industries and landfills. Anthropogenic nitrous oxide sources include fertilizer, manure, crop residues and nitrogen-fixing crops production. Methane and nitrous oxide are also emitted in large amounts from natural sources. The 100-year global warming potentials of methane and nitrous oxide are recently estimated at 25 and 298 carbon dioxide equivalents, respectively. Steinfeld et al. estimate that