Human activities globally emit about 35 billion tons of CO2 every year.
An additional 15 billion tons of CO2 equivalent emissions happen from sources outside of CO2 - mainly from methane & N2O, some from refrigerant gases, and gases such as SF6 used in applications such as sealants.
Methane emissions happen from cattle & livestock emissions, from landfills, and leaks of methane from natural gas production and distribution infrastructure (natural gas flaring is another source of emissions, but the methane gets converted to CO2 in this process).
About three quarters of all global N2O emissions mainly occur from agricultural fields where the nitrogen in the excess fertilizer that had not been absorbed by the crops gets converted into N2O.
R-22, the common refrigerant in use today, has a global warming potential that is about 2000 times that of CO2. Thus, even relatively small amounts of leaks of this refrigerant could mean significant enhancements to global warming. Similar is the case with SF6, which has a potential that is 22,000 times that of CO2 over a hundred year period.
Given the diverse nature and sources of these emissions, it will be quite challenging to mitigate all of them quickly. Some of these sources - landfill emissions, for instance - could see significant successful abatement efforts during the 2020-2030 period, while others - for instance, controlling N2O emissions from agriculture - could prove far more challenging.
For the 2020-2030 period, innovations for this domain will be around leakage detection systems, alternative refrigerants, landfill gas management, and solutions for farmers to decrease N2O emissions through alternative fertilizers or from better fertilizer application systems.
N2O comprises about 6.5% of total GHG emissions, or about 3.3 billion tons CO2 equivalent per year. 75% of these emissions come from the agricultural operations.
82 million tons of methane emissions - equivalent to about 1.8 billion tons CO2 - occurred from oil and gas operations in 2019, split in roughly equal parts between the two. These emissions came from a wide variety of sources along the oil and gas value chains, from conventional and unconventional production, from the collection and processing of gas, as well as from its transmission and distribution to end-use consumers. Some emissions are accidental, for example because of a faulty seal or leaking valve, while others are deliberate, often carried out for safety reasons or due to the design of the facility or equipment.
The HFC gases, used mainly as refrigerants, contribute about 1.1 billion tons of CO2 equivalent emissions per year. HFC-134a and HFC-152a account for the majority of emissions from all HFC variants.
About 300 million tons of CO2 equivalent emissions happen from SF6 and PFC together. About 8000 tons of SF6 are emitted per year, mainly from its use in gas insulated switchgear. As SF6 has a very high GWP potential (about 23500 times that of CO2), SF6 contributes to almost 200 million tons of CO2 equivalent emissions per year. PFCs are used in the electronics industry for semiconductor production and contribute to about 100 million tons of CO2 equivalent per year.
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Reducing Non-CO2 Industrial & Agricultural Emissions Decarbonization Avenue
