Share of non-CO2 pollutants contributing to global warming almost as much as CO2
- May 27, 2022
- Posted by: OptimizeIAS Team
- Category: DPN Topics
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Share of non-CO2 pollutants contributing to global warming almost as much as CO2
Subject :Environment
Section : climate change
Concept :
- Global temperatures are likely to exceed 1.5 degrees Celsius over pre industrial levels by 2035 and 2°C by 2050 if the focus is merely on decarbonisation efforts.
- The Working Group III report of the Intergovernmental Panel for Climate Change (IPCC), which deals with mitigating climate change, focuses on CO2 and a few greenhouse gases, but excludes other non-CO2 pollutants.
- There is a need to urgently bend the emission curve of methane, HFCs, black carbon soot and a few other precursor gases that increase lower atmosphere ozone.
Green House effect :
- Some atmospheric gases absorb and re-emit infrared energy from the atmosphere down to the Earth’s surface. This process, the greenhouse effect, leads to a mean surface temperature that is 33 °C greater than it would be in its absence. If it were not for the greenhouse gas effect, Earth’s average temperature would be a chilly -18 °C.
- The Earth has a natural greenhouse effect due to trace amounts of water vapour (H2O), carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) in the atmosphere. These gases let the solar radiation reach the Earth’s surface, but they absorb infrared radiation emitted by the Earth and thereby lead to the heating of the surface of the planet.
- One needs to distinguish between the natural greenhouse effect and the enhanced greenhouse effect. The natural greenhouse effect is caused by the natural amounts of greenhouse gases, and is vital to life. In the absence of the natural greenhouse effect the surface of the Earth would be approximately 33 °C cooler. The enhanced greenhouse effect refers to the additional radiative forcing resulting from increased concentrations of greenhouse gases induced by human activities
- The main greenhouse gases whose concentrations are rising are carbon dioxide, methane, nitrous oxide, hydrochlorofluorocarbons (HCFCs), hydrofluorocarbons (HFCs) and ozone in the lower atmosphere.
- The Global Atmosephere Watch (GAW) observes, analyses and publishes greenhouse gas data collected by fifty countries around the globe from the High Arctic to the South Pole. The greenhouse gases monitored include:
- Carbon Dioxide (CO2) (incl. Δ14C, δ13C and δ18O in CO2, and O2/N2 Ratios)
- Methane (CH4)
- Nitrous Oxide (N2O)
- Halocarbons and SF6
- Molecular Hydrogen (H2)
- Without tackling non-CO2 pollutants, these gases will continue to trap heat and keep the warming above 1.5°C, as there are not many cooling aerosols to mask the warming.
- The Glasgow Climate Pact, an agreement signed during the 2021 United Nations Climate Change Conference (CoP26), recognised the need to consider further actions to reduce non-carbon dioxide greenhouse gas emissions, including methane, by 2030.