Additional references and tables
What is SF6 (National Grid) https://www.nationalgrid.com/stories/energy-explained/what-is-sf6-sulphur-hexafluoride-explained#:~:text=It’s%20estimated%20that%2C%20over%20a,has%20a%20GWP%20of%2024%2C300.
Major Greenhouse Gases Associated with human activities (US Environmental Protection Agency): https://www.epa.gov/climate-indicators/greenhouse-gases
Major greenhouse gases associated with human activities
| Greenhouse gas | How it’s produced | Average lifetime in the atmosphere | 100-year global warming potential |
|---|---|---|---|
| Carbon dioxide | Emitted primarily through the burning of fossil fuels (oil, natural gas, and coal), solid waste, and trees and wood products. Changes in land use also play a role. Deforestation and soil degradation add carbon dioxide to the atmosphere, while forest regrowth takes it out of the atmosphere. | See the footnote* | 1 |
| Methane | This gas is emitted during the production and transport of oil, natural gas, and coal. Methane emissions also result from livestock and agricultural practices and from the anaerobic decay of organic waste in municipal solid waste landfills. | 11.8 years | 27.0–29.8** |
| Nitrous oxide | Nitrous oxide emissions are a result of agricultural and industrial activities, as well as during the combustion of fossil fuels and solid waste. | 109 years | 273 |
| Fluorinated gases | A group of gases that contain fluorine, including hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride, among other chemicals. These gases are emitted from a variety of industrial processes, commercial and household uses, and do not occur naturally. Sometimes used as substitutes for ozone-depleting substances such as chlorofluorocarbons. | A few weeks to thousands of years | Varies (the highest is sulfur hexafluoride at 25,200) |
This table shows 100-year global warming potentials, which describe the effects that occur over a period of 100 years after a particular mass of gas is emitted. Global warming potentials and lifetimes come from Tables 7.15 and 7.SM.7 of the Intergovernmental Panel on Climate Change’s Sixth Assessment Report, Working Group I contribution.3
* Carbon dioxide’s lifetime cannot be represented with a single value because the gas is not destroyed over time, but instead moves among different parts of the ocean–atmosphere–land system. Some of the excess carbon dioxide is absorbed quickly (for example, by the ocean surface), but some remains in the atmosphere for thousands of years, due in part to the very slow process by which carbon is transferred to ocean sediments.
** Methane’s global warming potential is shown as a range that includes methane from both fossil and non-fossil sources.
Tables 7.15 and 7.SM.7 of the Intergovernmental Panel on Climate Change’s Sixth Assessment Report: https://www.ipcc.ch/report/ar6/wg1/downloads/report/IPCC_AR6_WGI_Chapter07_SM.pdf
EU F-gas Regulations: F-gases: new rules on labelling, reporting, certification and the F-gas Portal – European Commission
EU-Rules – Fluorinated Greenhouse Gases – Climate Action
UK F-gas Regulations: The Fluorinated Greenhouse Gases Regulations 2015
Major greenhouse gas sources, lifespans, and possible added heat
| Greenhouse gas | Sources (contribution to global warming) | Average lifespan in the atmosphere | Possible added heat [Global Warming Potential (GWP)]over a 20-year period | Possible added heat over a 100-year period |
|---|---|---|---|---|
| Carbon dioxide | Human sources (100%): mMostly the burning of fossil fuels (such as coal, oil, and natural gas); deforestation/land use change; and wildfires/biomass (plant material) burning.Natural sources (0%): Volcanic eruptions; respiration; weathering of certain rocks; wildfires/biomass burning; permafrost. | Hundreds to thousands of years | Carbon dioxide is used as a reference point for other greenhouse gases, so the possible added warming (or GWP) is 1. | Carbon dioxide is used as a reference point for other greenhouse gases, so the possible added warming (or GWP) is 1 |
| Methane | Human sources (60%): Leaks from fossil fuel production and transportation; landfills; livestock digestion and manure; rice farming; natural gas; wildfires/biomass burning.Natural sources (40%): Plant matter breakdown in wetlands, lakes, ponds; wildfires/biomass burning; termites, ocean; sediment; volcanoes; permafrost. | About a decade | One metric ton can trap about 80 times the heat of 1 metric ton of carbon dioxide. | One metric ton can trap about 30 times the heat of 1 metric ton of carbon dioxide. |
| Nitrous Oxide | Human sources (40%): Production and use of organic and commercial fertiliser; burning fossil fuels; burning vegetation.Natural sources (60%): Bacteria breaking down nitrogen in soil and the ocean. | About 110 years | One metric ton can trap about 273 times the heat of 1 metric ton of carbon dioxide. | One metric ton can trap about 273 times the heat of 1 metric ton of carbon dioxide. |
| Chlorofluorocarbons (CFCs, CFC-11, CFC-12, CFC-113) | Human sources (100%): Refrigerants; solvents (a substance which dissolves others); spray can propellants. Natural sources (0%): None | About 52 – 93 years | One metric ton can trap thousands to tens of thousands of times the heat of 1 metric ton of carbon dioxide. | One metric ton can trap thousands to tens of thousands of times the heat of 1 metric ton of carbon dioxide. |
| Sulfur hexaflouride (SF6) | Human sources (100%): SF6 is used in the electricity industry as an insulation gas to keep networks running safely and reliably.Natural sources (0%): None | 800 – 3,200 years | One metric ton can trap between 22,800 – 25,200 times the heat of 1 metric ton of carbon dioxide. | One metric ton can trap between 22,800 – 25,200 times the heat of 1 metric ton of carbon dioxide. |