Navigating terminology surrounding climate change can be challenging, with phrases often wrongfully being used interchangeably. To assist, we’ve compiled a list of common words, abbreviations, and terminology.
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Greenhouse gases (also known as GHGs) are gases in the earth’s atmosphere that trap heat. Burning fossil fuels, cutting down forests and farming livestock adds enormous amounts of greenhouse gases to those naturally occurring in the atmosphere, increasing the greenhouse effect and global warming. The GHGs are:
Carbon dioxide (CO2): Carbon dioxide enters the atmosphere through burning fossil fuels (coal, natural gas, and oil), solid waste, trees and other biological materials, and also as a result of certain chemical reactions (e.g., cement production). Carbon dioxide is removed from the atmosphere when it is absorbed by plants.
Methane (CH4): Methane is emitted during the production and transport of coal, natural gas, and oil. Methane emissions also result from livestock and other agricultural practices, and by the decay of organic waste in landfills.
Nitrous oxide (N2O): Nitrous oxide is emitted during agricultural land use, industrial activities, combustion of fossil fuels and solid waste, as well as during treatment of wastewater.
Fluorinated gases: Hydrofluorocarbons, perfluorocarbons, sulfur hexafluoride, and nitrogen trifluoride are synthetic, powerful greenhouse gases that are emitted from a variety of household, commercial, and industrial applications and processes. Fluorinated gases (especially hydrofluorocarbons) are sometimes used as substitutes for stratospheric ozone-depleting substances (e.g., chlorofluorocarbons, hydrochlorofluorocarbons, and halons).
Global GHG Emissions by Gas
| GHG | % of total GHG emitted globally |
| CO2 | 74.4 |
| CH4 | 17.3 |
| N2O | 6.2 |
| F-gases | 2.1 |
Global Warming Potential (GWP) describes how much impact a GHG will have on atmospheric warming over a period of time compared to carbon dioxide. Each GHG has a different atmospheric GWP, and some gases remain in the atmosphere for longer than others. Carbon dioxide (CO2) has the lowest warming potential, is the most abundant and lasts for thousands of years, so it is used as the baseline.
The GWP for other gases shows the warming effect in CO2 equivalent terms over time. For example, the GWP100 for Methane is 29.8. This means that 1 tonne of methane causes the same amount of warming as 29.8 tonnes of CO2 (in this case over 100 years).
| GHG | GWP100 |
| Carbon dioxide (CO2) | 1 |
| Methane (CH4) | 29.8 |
| Nitrous oxide(N2O) | 273 |
| Hydrofluorocarbons (HFCs) | 5 – 14,600 |
| Perfluorocarbons (PFCs) | 78 – 12,400 |
| Sulphur hexafluoride (SF6) | 25,200 |
| Nitrogen trifluoride (NF3) | 17,400 |
The Conference of Parties (COP) is a series of United Nations climate change conferences which have been running since 1995. The goal of these conferences is to review progress made by members nations of the United Nations Framework Convention on Climate Change (UNFCCC) to limit climate change. COP takes place every year, unless agreed otherwise by the parties. COP28 took place in Dubai, UAE in 2023.
The carbon (or emission) budget is the volume of greenhouse gases (measured in carbon dioxide equivalent) which can be emitted into the atmosphere before we reach dangerous levels of global temperature rise.
The Paris Agreement aims to limit global temperature increase to well below 2°C above preindustrial levels and pursue efforts to limit it to 1.5°C. The remaining carbon budget is commonly used to assess global progress against these targets.
The new study estimates that for a 50% chance of limiting warming to 1.5°C, there are less than 250 gigatonnes of carbon dioxide equivalent left in the global carbon budget.
If a company, service, or product is labelled as Carbon Neutral it means carbon offsets have been bought to balance out the CO2 emissions, or optionally CO2e emissions, created during business activities or production of said product. Typically, only scope 1 and 2 emission must be offset in order for a company, service of product to be classed as carbon neutral.
Net Zero is about reducing all GHG emissions to as close to zero as possible and then the purchase of carbon offsets for the very essential, hard to decarbonise, emissions that remain. The SBTi Net-Zero Standard requires companies to target to achieve a 90% reduction in Scope 1, 2 & 3 emissions by 2050 in order to be verified. This is in line with keeping global warming to 1.5°C, as specified by the Paris Agreement. The leftover emissions must then be neutralised through high quality and verified carbon removal credits as opposed to carbon reduction credits.
Check out our other articles and whitepapers to help broaden your understanding around these topics and find out how we are taking measure to enhance our sustainability efforts, if you have any questions please get in touch wecare@hazel4d.com.
