Carbon Glossary

Concept Acronym Description
Additionality   Carbon credits from projects that are 'additional to' the business-as-usual scenario. such projects would NOT have happened in the normal course of business.
Allowance   Authorization to emit, during a specified year, up to one ton of carbon dioxide equivalent.
Alternative compliance mechanism   Actions to achieve the equivalent reduction of greenhouse gas emissions over the same time period as a direct emission reduction. Includes, but not limited to:
  • Alternative control technology which removes or cleans GHG currently being emitted.
  • Process or product change which lowers GHG over previous production.
  • Flexible compliance schedule.
Carbon dioxide equivalent   The amount of carbon dioxide by weight that would produce the same global warming impact as a given weight of another greenhouse gas, based on the best available science, including IPCC. 
Cost-effectiveness   The cost per unit of reduced emissions of greenhouse gases adjusted for its global warming potential. 
Direct emission reduction   A greenhouse gas emission reduction action made by a greenhouse gas emission source at that source. 
Emissions reduction measure   Any mechanism, authorized by a regulatory agency, applicable to sources designed to reduce emissions of greenhouse gases.
Greenhouse gas GHG Includes carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons, and sulfur hexaflouride.
Greenhouse gas emissions limit   An authorization by a regulating entity, during a specified year, to emit up to a level of greenhouse gases expressed in tons of carbon dioxide equivalents. 
Greenhouse gas emission source   Any source of greenhouse gas emissions whose emissions are at a level of significance, as determined by regulatory agency,
Intergovernmental Panel on Climate Change IPCC Assesses the scientific, technical and socio-economic information relevant for the understanding of the risk of human-induced climate change.
Leakage   A reduction in emissions of greenhouse gases within the state that is offset by an increase in emissions of greenhouse gases outside the state.
Market-based Compliance Mechanism   A market-based system for reducing aggregate emissions from sources that emit greenhouse gases. Includes: greenhouse gas emissions exchanges, banking, credits, and other transactions, governed by rules and protocols established by regional, state or local entities.
Offset   A project that compensates or an allowance made in order to counterbalance carbon emssions at another location.
Reducing Emissions from Deforestation and Forest Degradation REDD Steps designed to use market or other financial incentives to reduce the emissions of greenhouse gases from deforestation and forest degradation. Actions taken under REDD may be used to offset emissions.
Regional Green House Gas Initiative (Pronounced Reggie) RGGI The first regional market-based regulatory program in the United States to reduce greenhouse gas emissions in subscribing North Eastern states
Regulating Agency   Agency or State Authority responsible for implementing regional, state or local GHG reduction initiatives.
Renewable Energy Certificats  REC Also known as Green tags, Renewable Energy Credits, Renewable Electricity Certificates, or Tradable Renewable Certificates (TRCs), are tradable energy commodities that represent proof that 1 megawatt-hour (MWh) of electricity was generated from an eligible renewable energy resource (renewable electricity).
Western Climate Initiative WCI The WCI Partner jurisdictions plan to reduce regional GHG emissions to 15 percent below 2005 levels by 2020 and spur investment in and development of clean-energy technologies, create green jobs, and protect public health. Current subscribers include California and five Canadian provinces.