Global Warming

Greenhouse gases (GHGs) are atmospheric gases that trap heat and contribute to the greenhouse effect, thereby warming the Earth. While some of these gases occur naturally, human activities have significantly increased their concentration, intensifying global warming.

• Carbon Dioxide (CO₂)
• Since the beginning of the industrial era in the 18th century, human activities have led to a dramatic 50% increase in atmospheric carbon dioxide (CO₂) levels. Today, CO₂ concentrations are 150% higher than their pre-industrial levels in 1750. This rise, driven primarily by fossil fuel combustion and deforestation, is significantly steeper than the natural increase that occurred over the 20,000 years following the last Ice Age.
• Sources:
  • Burning of fossil fuels (coal, oil, natural gas)
  • Deforestation and land use change
  • Industrial processes (cement production)
  • Wildfires
  • Natural processes like volcanic eruptions. 
• Note: It is the most significant anthropogenic GHG in terms of volume.
• Methane (CH₄)
• Sources:
  • Natural sources such as wetlands.
  • Smaller sources include termites, oceans, sedirnents, volcanoes, and wildfires.
  • Livestock digestion (enteric fermentation)
  • Paddy cultivation (anaerobic decomposition)
  • Landfills and waste treatment
  • Natural gas and petroleum systems
• Nitrous Oxide (N₂O)
• It is naturally present in rhe atmosphere as part of the Earth’s nitrogen cycle, and has a variety of natural sources.
• Sources:
  • Agricultural fertilizers (especially nitrogen-based)
  • Biomass burning
  • Industrial processes
  • Emitted when transportation fuels are burned.
  • Natural emissions of Nitrous Oxide are mainly from bacteria breaking down nitrogen in soils and the oceans.
  • Generated as a byproduct during the production of nitric acid, which is used to make synthftic commercial fertilizeq and in the production of adipic acid, which is used to {nake fibers, like nylon, and other synthetic products
• Water Vapor
  • Water vapour is the largest natural contributor to the greenhouse effect. However, humans do not directly emit water vapour in quantities large enough to significantly increase its concentration in the atmosphere.
  • Instead, human-induced greenhouse gases like carbon dioxide (CO₂) raise global temperatures, which in turn increase evaporation from oceans and other water bodies. This leads to more water vapour in the air — and since water vapour itself is a greenhouse gas, this creates a positive feedback loop that amplifies warming.
  • Unlike CO₂, which can linger in the atmosphere for centuries, water vapour cycles quickly — evaporating and then falling back as rain or snow. But its concentration is closely tied to temperature, meaning more CO₂ in the air means more water vapour — and thus, more warming.
• Fluorinated Gases
• Fluorinated gases (F-gases) are a family of gases containing fluorine. They are powerful greenhouse gases that trap heat in the atmosphere and contribute to global warming. They are stronger than naturally occurring greenhouse gases and their use is regulated
• It includes HFCs, PFCs, SF₆, NF₃.
• Hydrofluorocarbons, perfluorocarbons, sulfur hexafluoride, and nitrogen trifluoride are synthetic, powerful greenhouse gases that are emitted from a variety of household, commercial, and industrial applications and processes.
• Fluorinated gases (especially hydrofluorocarbons) are sometimes used as substitutes for stratospheric ozone-depleting substances (e.g., chlorofluorocarbons, hydrochlorofluorocarbons, and halons).
• Fluorinated gases are typically emitted in smaller quantities than other greenhouse gases, but they are potent greenhouse gases.
• With global warming potentials (GWPs) that typically range from thousands to tens of thousands, they are sometimes referred to as high-GWP gases because, for a given amount of mass, they trap substantially more heat than CO₂.
• Sources:
  • Fluorinated greenhouse gases are emitted through a variety of industrial processes such as aluminum and semiconductor manufacturing & Substitution for Ozone– Depleting Substances.
  • Refrigeration and air conditioning
  • Industrial solvents
  • Electronics manufacturing
• Note: Entirely human-made; though present in smaller quantities, their global warming potential (GWP) is extremely high — up to thousands of times greater than CO₂.