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Global CO2 Emissions

We have only one Earth!


Carbon dioxide - CO2


Carbon dioxide (CO2) is a colorless, odorless, and non-poisonous gas formed by the combustion of carbon-containing fuels and in the respiration process of living organisms [EC, 2022].  Together w/ water vapor methane, CO2 is considered a greenhouse gas (GHG), i.e., a gas that absorbs infrared radiation and radiates heat in all directions, leading to the global warming, the long-term heating of earth’s surface observed since the pre-industrial period (1850-1900) [NASA, 2023].

Greenhouse gas - GHG


GHG collectively make up less than 1% of the Earth’s atmosphere.  The GHG whose concentrations are rising are CO2, methane (CH4, 25x as potent as CO2, and the 2nd most abundant anthropogenic GHG after CO2, accounting for about 20% of the global emissions), nitrous oxide (N2O), and F-gases (Fluorinated gases), i.e., industrial gases such as hydrofluorocarbons (HFC), perfluorocarbons (PFC), sulfur hexafluoride (SF6), and nitrogen trifluoride (NF3).  Figure 1 shows the composition of GHG.


Other GHG not counted in international GHG inventories are ozone water vapor, the latter being the largest GHG contributor, but often ignored (Figure 1).  Although it is the most abundant GHG, it is believed that anthropogenic emissions of water vapor contribute very little to the amount of water vapor in the atmosphere [IEA, 2022].


Global CO2 emissions


CO2 emissions are largely connected w/ energy (Figure 2) resulting of burning fossil fuels such as coal, oil, and natural gas.  Industry & electric power generate more than half of global GHG emissions, as can be seen in Figure 3.  China, U.S., and India are the top three CO2 emitters in the world.  Figure 4 shows the GHG emissions from the world’s largest emitters [RG, 2022].  Metals & mining industry is responsible for approximately 15% of annual global emissions [WM, 2023]: Figure 5 shows that emissions intensity varies widely by commodity and across the value chain.

Carbon dioxide equivalent - CO2e


Carbon dioxide equivalent, or CO2e (expressed as million metric tons of carbon dioxide equivalents - MMTCDE) is a measure used to compare the emissions from various GHG (CO2, CH4, NO2, HFC4 etc.) on the basis of their global-warming potential (GWP), by converting amounts of other gases to the equivalent amount of CO2 with the same global warming potential (here CO2 and CO2e are used interchangeably). Global CO2 emissions from energy combustion & industrial processes grew 0.9% or 321 Mt in 2022 to a new all-time high of 36.8 Gt from a total of about 50 Gt [IEA, 2023].


Carbon credit - CC


A carbon credit (CC) is a kind of permit that represents 1 ton of CO2 removed from the atmosphere, that can be purchased by an individual or a company to make up for CO2 emissions that come from industrial production, delivery vehicles, or travel.  Thus, CC is a certificate granted to companies or entities that emit GHG.


CC may be regulated or voluntary.  In regulated (or compliance) markets (typically in wealthy countries), the government establish a regulatory body for ensuring compliance within annual rules & limits.  The regulator also determines the minimum price for CC [AHDB, 2023].  In voluntary markets, credits can be sold btw private parties.  2020 saw an increased demand on CC due to the Paris Agreement, which set goals around reducing GHG emissions.

CC price & market


CC price fluctuates depending on demand & supply and currently (2023) ranges from USD 40-80 per ton [8BT, 2023]but may reach USD 250 under the removal scenario [BB, 2023] Moreover, CC are valued taking into account the differences among the projects: Figure 6 shows transacted volume, average price, and price range by project type, in 2015.  The global CC traded value was USD 978.56 billion in 2022.  The market is expected to reach USD 2.68 trillion by 2028 (CAGR of 18.23% in 2023-2028) [YF, 2023].




Tokenization of CC means that the carbon credits’ information and functionality are moved into a specific type of database called blockchain (a digital ledger of transactions), where the CC is represented as a token.  These tokens represent measurable, verifiable reductions in GHG emissions.

Figure 1:  Composition of greenhouse gases (GHG)

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Figure 2:  Global GHG emissions (2020)

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Figure 3:  Global GHG emissions by sector (2020)

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Figure 4:  GHG emissions from the world’s largest emitters


Figure 5:  Emissions intensity varying by commodities and across the value chain


Figure 6:  Transacted volume, average price, and price range by project type - 2015

Fig 3 GHG by sector
Fig 4 GHG emitters
Fig 2 - Emissions Energy
Fig 5 Emissions intensities
Fig 1 Carbom nitr
Fig 6 Tansicton volume
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