Greenhouse Gas Bulletin 2022

CO2 is responsible for about 81% of the increase in radiative forcing over the past decade and about 80% of the increase over the last five years.

Accumulation: Out of the total emissions released from human activities during the 2011–2020 period, about 48% accumulated in the atmosphere, 26% in the ocean and 29% on land.

Effects: In future, the ability of lands and oceans to become carbon sinks will be affected and as a result, they will start becoming source of CO2 emission.

Source: The largest contribution to the renewed increase in methane since 2007 is a result of biogenic sources, such as wetlands or rice paddies. Anthropogenic sources at the mid-latitudes of the northern hemisphere are also a major reason for increase.

Feedback effect: It is assumed that increased methane creates a feedback effect that includes faster decomposition of organic matter, resulting in further methane emissions.

Climate event: Climatic events such as La Niña events increase precipitation in the tropics, which are associated with increase in methane emissions.

The increase in NO2 emissions from 2020 to 2021 was slightly higher than that observed from 2019 to 2020.

Source: Global human-induced N2O emissions are dominated by nitrogen additions to croplands. It has increased by 30% over the past four decades. This increase in emission was mainly responsible for the growth in the atmospheric burden of N2O.

Sulfur hexafluoride (SF6) is an extremely potent greenhouse gas and is produced by the chemical industry, mainly as an electrical insulator in power distribution equipment.

Smaller compounds such as carbon monoxide, nitrogen oxides and volatile organic compounds, although not considered as greenhouse gases, have small direct or indirect effects on radiative forcing.

Aerosols (suspended particulate matter) are short-lived compounds/matter that can alter the radiation budget.