Greenhouse Gases | SSC CGL Tier 2 - Study Material, Online Tests, Previous Year PDF Download

Introduction to Greenhouse Gases

Acting like a blanket, these gases trap and release infrared radiation, playing a crucial role in regulating Earth's temperature.

Understanding the Greenhouse Effect:

• The greenhouse effect, a natural occurrence, maintains Earth's lower atmosphere at a temperature conducive to life. 
• Similar to how greenhouses retain warmth, water vapor and greenhouse gases contribute to this process. 
• These gases participate in Earth's cooling and warming cycles, ensuring a habitable environment. However, human-induced greenhouse gas emissions disrupt this balance, leading to elevated temperatures and impacting climate patterns.

Water Vapor: A Dominant Greenhouse Gas

• Water vapor, a gaseous form of water, is the most significant contributor to the greenhouse effect. 
• While humans do not directly emit enough water vapor to alter atmospheric concentrations, its continuous production through evaporation and removal by condensation influences weather patterns. 
• As an effective greenhouse gas, water vapor absorbs and radiates longwave radiation, contributing to the overall warming effect. It remains the most abundant greenhouse gas by weight and volume.

Carbon Dioxide's Role in the Greenhouse Effect

• Carbon dioxide (CO₂), a substantial heat-trapping gas, results from fossil fuel extraction, combustion, wildfires, and natural processes like volcanic eruptions. 
• Transparent to incoming solar radiation but opaque to outgoing terrestrial radiation, CO₂ is a major contributor to the greenhouse effect. 
• Emitted by both human and natural sources, it accumulates near the Earth's surface, leading to global temperature rise and subsequent climate change.

Methane's Potency as a Greenhouse Gas

• Methane, a potent greenhouse gas, exhibits a global warming potential 28-34 times that of CO₂. 
• Approximately 60% of global methane emissions result from human activities, including oil and gas industries, agriculture, landfills, and coal mines. 
• Its release during fossil fuel production contributes to economic and environmental challenges, emphasizing the need for mitigation strategies.

Nitrous Oxide's Impact on the Greenhouse Effect

• Nitrous oxide, a naturally occurring gas in the Earth's nitrogen cycle, possesses significant global warming potential. 
• While its concentration is low compared to CO2, its heat-trapping ability per molecule is 298 times greater over a 100-year period. 
• Human activities, such as fossil fuel combustion and fertilizer application, increase nitrous oxide levels, contributing to the greenhouse effect and influencing atmospheric chemistry.

Fluorinated Gases: Unnatural Contributors to Global Warming:

• Fluorinated gases, distinct from many natural greenhouse gases, stem predominantly from human activities like ozone-depleting substitutes and industrial processes. 
• Due to their exceptionally high global warming potentials, even minimal atmospheric concentrations exert substantial effects on global temperatures. 
• These long-lasting gases, with lifetimes lasting thousands of years, are formidable contributors to human-induced climate change.

Black Carbon: A Climate Menace

• Black carbon, a particulate air pollutant resulting from incomplete combustion of fossil fuels, biofuel, and biomass, constitutes a significant environmental concern. 
• Released by various sources, including gas and diesel engines, as well as coal-fired power plants, BC comprises nearly pure elemental carbon with trace amounts of oxygen and hydrogen. 
• Recognized as the second most impactful anthropogenic agent for climate change among aerosols, BC plays a crucial role in understanding the adverse effects of air pollution.

Impact and Characteristics of Black Carbon

• Black carbon contributes to Earth's warming by absorbing atmospheric heat and reducing albedo, particularly when deposited on snow and ice. 
• Its presence darkens snow packs and glaciers, accelerating their melting. Regionally, BC disrupts cloudiness, monsoon rainfall, and expedites the melting of mountain glaciers, such as the Hindu Kush-Himalayan glaciers. 
• Despite being a short-lived pollutant, BC stands as the second-largest contributor to global warming, following carbon dioxide (CO₂).

Brown Carbon: Unveiling Another Aspect

• Brown carbon, emanating from the burning of organic matter, coexists with black carbon when released into the atmosphere. 
• Displaying a light brownish color, brown carbon significantly influences atmospheric temperature patterns, cloud formation processes, and solar absorption characteristics. 
• While absorbing in ultraviolet wavelengths, it exhibits lesser absorption in visible wavelengths. 
• The interplay of black and brown carbon underscores the complexity of their combined impact on the climate.

Global Initiatives to Tackle Greenhouse Gas Emissions

Several international initiatives aim to combat greenhouse gas emissions and address climate change:

1. Intergovernmental Panel on Climate Change (IPCC): Established in 1988, IPCC provides policymakers with scientific assessments, impacts, and risks of climate change, along with adaptation and mitigation alternatives.

2. United Nations Framework Convention on Climate Change: Enacted in 1992, this framework seeks to stabilize atmospheric greenhouse gas concentrations to prevent dangerous interference with the climate system.

3. Kyoto Protocol (KP): Adopted in 1997, KP targets a reduction of global greenhouse gas emissions by at least 5% compared to 1990 levels by 2012, encompassing various gases like CO2, CH4, and N2O.

4. Paris Agreement: Consensually adopted in 2015, this agreement strives to limit global temperature increases below 2 degrees Celsius above pre-industrial levels, with efforts to restrict it further to 1.5 degrees Celsius.

5. International Carbon Action Partnership (ICAP): Founded in 2007, ICAP focuses on cap and trade systems for GHG mitigation, promoting the exchange of best practices and design elements.

Conclusion: Mitigating Climate Change

Over the past 150 years, human activities, including fossil fuel usage and deforestation, have escalated greenhouse gas levels. To counteract climate change, reducing greenhouse gas emissions, especially carbon dioxide, is imperative. Initiatives such as tree planting, conservation of existing carbon sinks (forests, grasslands, peatlands, and wetlands), sustainable farming practices, carbon dioxide removal technologies, and reliance on renewable energy sources present viable solutions. The collaborative efforts outlined in international agreements underscore the global commitment to mitigating climate change and fostering a sustainable future.