The recent study has highlighted the urgent need for the world to target both non-CO2 and CO2 pollutants to meet climate targets. Focusing on decarbonization isn’t enough as it’s projected that global temperatures will exceed 1.5 degrees Celsius over pre-industrial levels by 2035, and 2°C by 2050. The study highlights the significant role of non-CO2 pollutants in contributing to global warming, almost as much as carbon dioxide.
Understanding Non-CO2 Pollutants
Non-CO2 pollutants include methane, black carbon, hydrofluorocarbons (HFC), tropospheric ozone, and nitrous oxide. Each of these contributes to environmental degradation in different ways.
Methane, a potent greenhouse gas, contributes to ozone formation. It’s primarily emitted from processes such as the extraction, distribution, and combustion of fossil fuel, industrial processes, and some agricultural processes. Black carbon, a primary component of PM2.5 and a strong warming agent in the atmosphere, contributes to regional environmental disruption and hastens glacier melting.
Hydrofluorocarbons (HFCs), commonly used in refrigeration, air-conditioning (AC), building insulation, fire extinguishing systems, and aerosols, are also greenhouse gases (GHGs). Tropospheric ozone forms through the interaction of sunlight, particularly ultraviolet light, with hydrocarbons and nitrogen oxides emitted by automobile tailpipes and smokestacks.
Lastly, nitrous oxide, a greenhouse gas that is 300 times more potent than carbon dioxide (CO2), mostly comes from industrial processes, agricultural soils, manure management, and wastewater.
Deciphering the Global Warming Contribution
IPCC report findings indicate that the contribution of CO2 and non-CO2 greenhouse gases to global warming stands at 52-57% and 43-48%, respectively. Thus, the influence of non-CO2 pollutants on global warming is nearly equal to that of carbon dioxide.
However, the current focus on mitigating climate change by institutions like the Intergovernmental Panel on Climate Change (IPCC) tends to be more CO2-oriented and excludes other non-CO2 pollutants. This is an issue because non-CO2 greenhouse gasses, along with black carbon soot, contribute nearly 80% of the global warming effect. Without addressing these non-CO2 pollutants, they will continue to trap heat, keeping global warming above the critical 1.5°C threshold.
Recent Initiatives to Tackle Non-CO2 Pollutants
Several initiatives have been taken to mitigate non-CO2 emissions. One such measure is the Glasgow Climate Pact, signed at the 2021 United Nations Climate Change Conference (CoP26). It recognizes the need for further reduction action on non-carbon dioxide greenhouse gas emissions, including methane, by 2030.
The Global Methane Pledge, launched by the US and EU at COP26, commits participating countries to cut methane emissions by 30% by 2030. However, India has not joined this pledge. Instead, the country’s Indian Council of Agricultural Research (ICAR) has developed an anti-methanogenic feed supplement ‘Harit Dhara’, which can reduce cattle methane emissions by 17-20%.
Way Forward
Addressing uncertainties around measuring non-CO2 pollutants, such as methane and aerosols, is imperative. The knowledge about their sources and mitigation methods also needs to become mainstream.
Reducing these emissions also poses a political question regarding responsibility allocation: whether coal-consuming and rice-producing countries in the Global South, or oil and gas-consuming countries in the North should take the lead. This necessitates a global agreement.
Relevant Previous Year Question for UPSC Civil Services Examination
In 2014, a question asked candidates to identify important pollutants released by the steel industry in India. The correct answer comprised oxides of sulfur, oxides of nitrogen, carbon monoxide, and carbon dioxide. Pollutants from the steel industry result primarily from the combustion of coal and iron ore, which release various harmful compounds into the air. Technological interventions like air filters, water filters, power-saving devices, and closed containers can help reduce these emissions.
Last Modified: February 15, 2024