Greenhouse Effect and Climate Change Notes with PDF

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1. Basic Concepts & Causes of Climate Change

• Definition: Long-term shift in global climate patterns, primarily attributed to human activities.
• Primary Cause: Enhanced Greenhouse Effect.
  • A natural process where atmospheric gases trap heat (infrared radiation), warming the Earth. Without it, the average temperature would be -18°C.
  • First postulated by Joseph Fourier in 1824.
  • Human activities intensify this effect by increasing the concentration of greenhouse gases.
• Key Drivers (Anthropogenic):
  • Increasing Atmospheric Carbon: Excessive burning of fossil fuels, explosion in the number of automobiles.
  • Reducing Carbon Absorption: Heavy deforestation.
  • Other Factors: Greenhouse gases, depletion of the ozone layer, and general pollution.
• Key Indicator:
  • The global average temperature has risen by 1.8°F (0.8°C) over the last century.

2. Greenhouse Gases (GHGs)

• Definition: Atmospheric gases that absorb and emit infrared radiation, trapping heat.
• Major Greenhouse Gases:
  • Carbon Dioxide (CO₂): The primary contributor to global warming after water vapor, due to its abundance.
  • Methane (CH₄): A much more potent GHG than CO₂ (up to 86 times more powerful over 20 years).
  • Nitrous Oxide (N₂O)
  • Water Vapor (H₂O)
  • Ozone (O₃)
  • Chlorofluorocarbons (CFCs)
• Gases that are NOT Greenhouse Gases:
  • Oxygen (O₂)
  • Argon
  • Oxides of Sulphur / Sulphur Dioxide (causes acid rain)
  • Nitrogen Oxide
  • Hydrogen
• Dual Nature of CO₂: Beneficial for photosynthesis (essential for food chains) but harmful as the primary anthropogenic greenhouse gas.

Sources of Major GHGs

• Carbon Dioxide (CO₂):
  • Thermal power stations (fossil fuels).
  • Deforestation and forest burning.
• Methane (CH₄):
  • Largest Source: Agricultural activities (cattle digestion, manure management).
  • Rice fields, coal mining, wetlands, landfills, natural gas systems.
• Nitrous Oxide (N₂O):
  • Waterlogged paddy fields, use of nitrogen-based fertilizers.
• Chlorofluorocarbons (CFCs):
  • Refrigerators and air conditioning systems (not a primary auto emission).
• Gases from Biomass Burning: Burning crop residue releases Carbon Monoxide (CO), Methane (CH₄), Ozone (O₃), and Sulphur Dioxide (SO₂).

3. Impacts & Consequences of Climate Change

• Environmental:
  • Melting Ice: Melting of glaciers and polar ice caps.
  • Sea-Level Rise: Rising at ~3 mm/year; projections of up to 1 meter by 2070 AD, threatening coral islands and low-lying countries (e.g., Fiji, Netherlands).
  • Ecosystem Damage: Bleaching of coral reefs, widespread coral mortality at >3°C warming.
  • Carbon Cycle Disruption: The terrestrial biosphere could become a net carbon source at >3°C warming.
  • Methane Release: Warming could trigger release of methane from Arctic tundra and seafloor hydrates.
• Biological & Ecological:
  • Shifts in species habitats and spread of diseases (e.g., mosquitoes).
  • Disruption of ecological synchrony (e.g., earlier flowering of mango trees).
  • 16-30% of known species face extinction with significant ecosystem transformation.
• Agricultural & Social:
  • Farming is the human activity most affected.
  • Alters water availability, reduces soil moisture/fertility/yields, increases soil salinity.
  • Impacts on food security can lead to increased social tension.
• Human Health: Adverse effects due to extreme weather and disease spread.

4. International Agreements & Initiatives

• UN Framework Convention on Climate Change (UNFCCC):
  • Opened for signature at the 1992 Earth Summit in Rio de Janeiro.
  • Entered into force on March 21, 1994. Ratified by 197 countries.
• Kyoto Protocol (1997):
  • Came into force in 2005.
  • Goal: Set binding targets to reduce emissions by 5.2% below 1990 levels.
  • Mechanisms: Clean Development Mechanism (CDM), Joint Implementation (JI), Emissions Trading.
  • Not related to: Saving water or primarily dealing with ozone depletion.
• Paris Agreement (COP 21, 2015):
  • Held in Paris, France.
  • Goal: Limit warming to well below 2°C, pursuing 1.5°C above pre-industrial levels.
  • Finance: Developed countries committed to mobilizing $100 billion/year by 2020 for developing nations.
• Other Protocols:
  • Montreal Protocol: Protects the Ozone Layer.
  • Cartagena Protocol: Related to Biosafety (living modified organisms).
  • Nagoya Protocol: Access to genetic resources and benefit-sharing.
  • Stockholm Convention: Deals with Persistent Organic Pollutants (POPs).
• Other Initiatives:
  • New York Declaration on Forests (2014): Voluntary pledge to halve forest loss by 2020 and end it by 2030. India is not a signatory.
  • Climate and Clean Air Coalition (CCAC): Voluntary partnership to reduce short-lived climate pollutants (methane, black carbon).
  • Earth Hour: WWF initiative (not UN) starting in Sydney, Australia (2007). A symbolic lights-off event.
  • Asia-Pacific Partnership: Members consume and contribute 48% of global energy/GHGs. Supports Kyoto Protocol.
  • Global Climate Change Alliance (GCCA): An initiative of the European Union.

5. Mitigation Strategies & Economic Measures

• Net-Zero Goal:
  • Concept: Balancing GHG emissions with absorption/removal from the atmosphere by 2050 (carbon neutrality), not reducing to absolute zero.
  • Mechanisms: Creating carbon sinks (forests), technology for carbon capture and storage.
  • Example: Bhutan is a carbon-negative country.
• Carbon Pricing:
  • Carbon Tax: A fee on fossil fuels (e.g., Singapore in 2019; New Zealand was first in 2005).
  • Carbon Credits (CER): Originated from the Kyoto Protocol. One credit = one ton of CO₂ reduction.
    • Price is market-driven, not fixed by UNEP.
    • Example: A 10-year agreement (2011) between the World Bank and the Himachal Pradesh government.
• Carbon Sequestration:
  • Process: Capturing and storing atmospheric CO₂ in sites like depleted oil/gas reservoirs, coal seams, deep saline formations.
  • Agricultural Practices: Contour bunding, relay cropping, zero tillage help store soil carbon.
• Forest-Based Mechanisms (REDD+):
  • REDD+: “Reducing Emissions from Deforestation and Forest Degradation.”
  • Forest Carbon Partnership Facility (FCPF): Launched by the World Bank (2008).
  • BioCarbon Fund Initiative (ISFL): Managed by the World Bank.
• Geo-Engineering: Proposals like cloud brightening over the Pacific using seawater.

6. Key Organizations, Research & Metrics

• Organizations & Programs:
  • Greenhouse Gas Protocol: Accounting tool by WRI and WBCSD (not a UN initiative).
  • CGIAR Research Programs: e.g., Climate-Smart Village Approach (CCAFS). ICRISAT in India is a CGIAR center.
  • Global Atmosphere Watch (GAW): WMO program; India does not host a station.
  • Deep Carbon Observatory (DCO): Global program to understand Earth’s carbon.
• Metrics & Rankings:
  • Carbon Footprint: Total GHGs produced to support human activities.
  • Top CO₂ Emitters: China (28%), USA (15%), India (7%), Russia (5%), Japan (3%).
  • Climate Change Performance Index (CCPI): Published by Germanwatch. India’s rank improved from 20th (2017) to 10th (2021).
• Scientific Concepts:
  • Carbon Fertilization: Increased plant growth from higher CO₂ concentrations.
  • Carbon Sinks: Oceans (via phytoplankton) and land plants absorb CO₂.
  • Astronomical Theories (Milankovitch Cycles): Natural long-term climate cycles due to changes in Earth’s orbit and tilt.

7. National Actions (India)

• National Action Plan on Climate Change (NAPCC): Released on June 30, 2008.
  • Comprises 8 National Missions (e.g., National Solar Mission, National Mission for Enhanced Energy Efficiency). Atomic Energy is not included.
• State Example – Jharkhand:
  • Action Plan published in 2013.
  • Saraikela Kharaswan is identified as the most climate-sensitive district (2014 report).
• Recognition: Hyderabad was recognized as a Tree City of the World (FAO & Arbor Day Foundation initiative).

Know More About Greenhouse Effect and Climate Change:

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