Greenhouse Effect and Climate Change

Greenhouse Effect and Climate Change is part of Environment and Ecology. Below are notes on 15 sub-topics, followed by practice MCQs from State PSC and UPSC papers.

Anthropogenic (Human-induced) Enhanced Greenhouse Effect

The Anthropogenic (Human-induced) En1. hanced Greenhouse Effect refers to an increase in the Earth's average surface temperature primarily due to human activities, intensifying the natural greenhouse effect. Anthropogenic activities are "extremely 2. likely" responsible for current rapid climate change, as per IPCC reports. Primary anthropogenic causes of increased 3. greenhouse gas emissions include:

• Excessive burning of fossil fuels (coal, oil, gas), especially since the Industrial Revolution.
• Exploding numbers of automobiles.
• Deforestation (e.g., since ~8000 years), which reduces CO2 absorption.
• Use of fire and overgrazing.
• Wet paddy (rice) cultivation (e.g., since ~5000 years), which is a major anthropogenic source of both Methane (CH4) and Nitrous Oxide (N2O). Climate change is considered a global negat4. ive externality caused by Greenhouse Gas (GHG) emissions. Impacts of climate change include: 5.
• Rapid pace of change. of species), Cultural/Spiritual, Recreational (ecotourism), Option Value (potential future uses/benefits).
• The Economics of Ecosystems and Biodiversity (TEEB):
• A global initiative focused on drawing attention to the economic benefits of biodiversity and ecosystem services.
• Hosted by UNEP (United Nations Environment Programme).
• Origin: Initiative of the G8+5 nations (2007).
• Purpose: Helps decision-makers recognize, demonstrate, and capture the value of ecosystems and biodiversity, promoting their integration into policy.
• Promotion of insect-borne diseases.
• Shift in climatic boundaries. China is currently the largest emitter of 6. Carbon Dioxide (CO2) and overall Greenhouse Gases (GHGs) globally (e.g., as per Emission Gap Report 2022). Mitigation strategies related to anthropogenic 7. sources:
• Organic farming reduces GHG emissions by enhancing CO2 absorption in the soil.
• System of Rice Intensification (SRI), through practices like alternate wetting and drying of rice fields, significantly reduces methane production, along with reduced seed requirement and electricity consumption.

Carbon Footprint, Carbon Sequestration, and Carbon Pricing Mechanisms

• Carbon Footprint: Total amount of Greenhouse Gases (GHGs) produced (directly & indirectly) to support human activities, vehicles, or industrial products.
• Greenhouse Gas Protocol: International accounting tool for governments and businesses to understand, quantify, and manage GHG emissions.
• Common Carbon Metric (UNEP supported): Developed for assessing the carbon footprint of building operations globally.
• Carbon Footprint Statistics & Targets:
• To prevent a 2°C rise in global temperature, the average global carbon footprint needs to drop to 2 tonnes per person by 2025.
• Average Carbon Footprint: USA = 16 tonnes/person; Global average = 4 tonnes/person.
• India is the third largest emitter of greenhouse gases (globally).
• As per World Resources Institute (2011), China was the world's highest carbon emitter. China was also the largest CO₂ emitter in 2015.
• Qatar is the highest per capita emitter of carbon dioxide.
• Delhi has the highest carbon footprint among Indian cities.
• Microsoft aims to remove all carbon emissions (direct or via electricity) since its 1975 founding by 2050.
• Carbon Sequestration: The process of capturing and long-term storage of atmospheric carbon dioxide (CO₂).
• Potential Carbon Sequestration Sites: Abandoned and uneconomic coal seams, depleted oil and gas reservoirs, subterranean deep saline formations.
• Carbon Sequestration Activities: Spreading finely ground basalt rock on farmlands, increasing the alkalinity of oceans by adding lime, capturing industrial CO₂ and pumping it into abandoned subterranean mines in the form of carbonated waters.
• Blue Carbon: Carbon captured by oceans and coastal ecosystems (e.g., mangroves, tidal marshes, seagrasses).
• Largest natural CO₂ Sink: Oceans.
• Not a good carbon sink: River. (Forests, wetlands, coal mines, oil/gas reservoirs are considered good sinks).
• Carbon Pricing: The economic value put on Greenhouse Gas (GHG) emissions.
• Carbon Tax: A tax levied on GHG emissions. It has been very successful in Sweden for reducing emissions.
• Carbon Credit:
• It is the difference between the carbon emission allowed and actually emitted carbon.
• One Carbon Credit (CC) = 1000 kg of CO₂ = 1 tonne of CO₂.
• Carbon Trading: Buying and selling of credits that allow an entity to emit a certain amount of greenhouse gases into the atmosphere. This concept was developed under the Kyoto Protocol (1997) from 2002 for industrially developed nations.
• Carbon Markets: A widespread tool in the fight against climate change, facilitating carbon trading.
• Social Cost of Carbon (SCC): A measure, in monetary value, of the long-term damage done by a tonne of CO₂ emissions in a given year.
• Carbon Border Adjustment Mechanisms (CBAM): Emerging trade tools meant to increase the environmental effectiveness of climate policies by preventing carbon leakage (movement of carbon-intensive economic activity to jurisdictions with less stringent climate policy).
• Emission Reduction Purchase Agreement (May 2011): Signed between the World Bank and the Government of India for a project in Himachal Pradesh, valid for 10 years. As per the agreement, one tonne of CO₂ is equivalent to one credit unit.

Climate Change Mitigation Strategies (e.g., renewable energy, carbon capture, afforestation)

carbon

capture,

afforestation)

• Net-Zero Emission: Achieved when anthropogenic greenhouse gas (GHG) emissions are balanced by anthropogenic removals over a specified period. This means any remaining emissions are compensated by absorption and removal of GHGs from the atmosphere (e.g., through creating carbon sinks like forests and utilizing technologies such as Carbon Capture & Storage - CCS). It does not imply bringing gross emissions to absolute zero. Countries are setting their Net-zero emission goals based on the long-term objectives outlined in the 2015 Paris Agreement.
• Kigali Amendment (2016): An amendment to the Montreal Protocol, focused on phasing down Hydrofluorocarbons (HFCs), which are potent greenhouse gases. It is projected to avoid up to 0.5°C of global warming by the end of the century.
• 'Decarbonising Transport in India' Project: Launched by NITI Aayog in collaboration with the International Transport Forum (ITF). Its aim is to develop a pathway towards a low-carbon transport system for India and design a tailor-made transport emissions assessment framework. It is part of the Decarbonising Transport in Emerging Economies (DTEE) project, with India, Azerbaijan, Nigeria, and Morocco as participating countries.
• 'Cooling Emissions and Policy Synthesis Report' (CEPSR): Jointly released by the United Nations Environment Programme (UNEP) and the International Energy Agency (IEA). This report assesses the development and climate benefits of efficient and climatefriendly cooling and outlines actions to deliver such cooling for all.
• Earth Hour: An initiative of the World Wide Fund for Nature (WWF). It is a global movement where participants switch off lights for one hour on a specific day annually to raise awareness about climate change and the need to conserve the planet.
• Forest Carbon Partnership Facility (FCPF): A global partnership comprising governments, businesses, civil society, and indigenous peoples. It assists countries in their REDD+ (Reducing Emissions from Deforestation and Forest Degradation+) efforts by providing financial and technical assistance to implement sustainable forest management practices and reduce deforestation and forest degradation.
• Geo-engineering Techniques (Solar Radiation Management - SRM): These techniques aim to reduce global warming by reflecting sunlight back into space:
• Cirrus Cloud Thinning: Involves modifying cirrus clouds to reduce their warming effect on Earth.
• Stratospheric Sulphate Aerosol Injection: Involves injecting sulphate aerosol (e.g., sulphur dioxide) into the stratosphere to increase its reflectivity, mimicking the cooling effect of large volcanic eruptions.
• Marine Cloud Brightening: Involves spraying fine sea water particles into the atmosphere over oceans to increase the reflectivity (albedo) of marine clouds, making them brighter and reflecting more solar radiation.

Climate Feedback Loops and Tipping Points

• Climate Feedback Loop: A process where an initial change in climate causes secondary changes that either amplify (positive feedback) or dampen (negative feedback) the initial change.
• Positive Feedback Loops (Amplify warming):
• Ice-Albedo Feedback: Warming melts highly reflective ice/snow (high albedo), exposing darker land/ocean surfaces (low albedo). Darker surfaces absorb more solar radiation, leading to further warming and more melting.
• Permafrost-Carbon Feedback: Thawing permafrost releases trapped CO2 and methane (potent GHGs) from decaying organic matter, increasing atmospheric GHG concentrations and causing further warming.
• Water Vapor Feedback: Warming increases evaporation, adding more water vapor (a potent GHG) to the atmosphere, which traps more heat, leading to more warming.
• Negative Feedback Loops (Dampen warming):
• Carbon Fertilization: Increased atmospheric CO2 can enhance plant photosynthesis and growth (up to a point), leading to more CO2 absorption by vegetation.
• Albedo Effect: A measure of the reflectivity of a surface. Surfaces with high albedo (e.g., ice, snow) reflect most solar radiation, while surfaces with low albedo (e.g., dark forests, oceans) absorb most solar radiation.
• Replacing high-albedo Arctic ice with lowalbedo dense forest would significantly increase solar radiation absorption, thereby accelerating global warming.
• Tipping Point: A critical threshold beyond which a system undergoes irreversible or abrupt, self-perpetuating changes, even if the initial forcing is removed.
• Key Climate Tipping Points (Potential): Loss of Arctic summer sea ice, collapse of Atlantic Meridional Overturning Circulation (AMOC), dieback of Amazon rainforest, thawing of permafrost, and collapse of major ice sheets (e.g., West Antarctic, Greenland).

Composition, Sources, and Radiative Forcing of Major Greenhouse Gases (GHGs)

• Greenhouse Gases (GHGs) are atmospheric gases that absorb and emit longwave (infrared) radiation, trapping heat and warming the Earth's surface and atmosphere.
• Major naturally occurring GHGs: Water Vapour (H₂O), Carbon Dioxide (CO₂), Methane (CH₄), Nitrous Oxide (N₂O), Ozone (O₃).
• Major anthropogenic GHGs: Carbon Dioxide (CO₂), Methane (CH₄), Nitrous Oxide (N₂O), Chlorofluorocarbons (CFCs), Hydrofluorocarbons (HFCs), Perfluorocarbons (PFCs), Sulphur Hexafluoride (SF₆).
• Gases that are NOT GHGs: Oxygen (O₂), Nitrogen (N₂), Argon (Ar), Carbon Monoxide (CO), Sulphur Dioxide (SO₂), Hydrogen (H₂), Helium. (CO and SO₂ are air pollutants, not primary GHGs).
• Kyoto Protocol's six main GHGs: CO₂, CH₄, N₂O, HFCs, PFCs, SF₆. Carbon tetrachloride (CTC) is not one of these six primary GHGs under Kyoto.
• Relative contribution to the greenhouse effect / global warming (approximate decreasing order): CO₂ > CH₄ > CFCs > N₂O.
• Global Warming Potential (GWP): Measures how much heat a GHG traps over a specific time horizon (e.g., 100 years) relative to CO₂. CO₂ has a GWP of 1.
• GHGs with highest GWP (most potent per molecule): SF₆ > PFCs > CFCs > N₂O > CH₄ > CO₂.
• Water Vapour (H₂O):
• Most abundant and most important naturally occurring GHG.
• Contributes the highest percentage (36-70%, excluding clouds) to the natural greenhouse effect.
• Its atmospheric concentration is primarily regulated by temperature, not directly by human emissions.
• Average atmospheric residence time: ~9 days.
• Carbon Dioxide (CO₂):
• Main component responsible for global warming and the greenhouse effect.
• Largest single contributor to anthropogenic radiative forcing.
• GWP: 1 (reference value).
• Current atmospheric concentration: ~417 ppm (May 2020), exceeding the often-cited safe threshold of 350 ppm.
• Sources:
• Natural: Respiration, decomposition, volcanic eruptions (minor compared to human sources).
• Anthropogenic: Burning of fossil fuels (power generation, vehicle exhaust), cement production, deforestation, biomass burning.
• Photosynthesis consumes CO₂, thus does not liberate it into the atmosphere.
• Raises atmospheric temperature by absorbing the infrared part of terrestrial radiation.
• "Carbon fertilization": Increased plant growth due to higher atmospheric CO₂ concentration.
• Congo Basin holds the world's largest tropical peatland, a significant carbon sink.
• Methane (CH₄):
• Potent GHG; GWP of ~21-28 over 100 years.
• Sources:
• Natural: Wetlands (main natural source), termites, oceans, permafrost thaw, natural gas hydrates.
• Anthropogenic: Paddy fields, livestock (enteric fermentation/ belching by cattle), coal mining, oil & gas leakage, landfills, wastewater treatment, biomass burning.
• Flaring (burning methane) converts it to CO₂ (less potent GHG), reducing its overall warming effect.
• Aliso Canyon (2016, US) experienced a major methane leakage.
• Nitrous Oxide (N₂O):
• Potent, long-lived GHG; GWP of ~265-298 over 100 years.
• Sources:
• Natural: Microbial processes in soils and oceans.
• Anthropogenic: Agricultural soil management (fertilizer use), livestock manure, industrial processes, combustion of fossil fuels and biomass, wastewater treatment.
• Depletes stratospheric ozone (impact comparable to CFCs) by reacting with it.
• Chlorofluorocarbons (CFCs):
• Entirely human-made (anthropogenic) GHG.
• Very potent GHGs with high GWPs and long atmospheric residence times (often maximum among common GHGs).
• Sources: Refrigerants, aerosol propellants, solvents, foam blowing agents.
• Strong ozone-depleting substances (ODS).
• Hydrofluorocarbons (HFCs):
• Man-made organic compounds (containing fluorine and hydrogen).
• Used as substitutes for CFCs/HCFCs (e.g., in refrigerators and air-conditioners).
• Do not deplete the ozone layer (zero Ozone Depletion Potential - ODP).
• Are potent GHGs and contribute to global warming.
• Perfluorocarbons (PFCs) & Sulphur Hexafluoride (SF₆):
• Man-made, extremely potent GHGs with very high GWPs and long atmospheric lifetimes.
• Mainly from industrial processes. SF₆ has the highest GWP among common GHGs.
• Ozone (O₃):
• A GHG.
• Beneficial in the stratosphere (blocks UV), but a pollutant and GHG in the troposphere.
• Aerosols (e.g., from SO₂):
• Directly reflect sunlight back to space.
• Indirectly make clouds brighter reflectors (cloud albedo effect).
• Have a net cooling effect on climate systems.
• Human-generated aerosols can offset global warming to some extent.
• Black Carbon (Soot) is a short-lived pollutant from incomplete combustion, accelerating warming by absorbing sunlight and reducing albedo.

Definition and Natural Greenhouse Effect

• The Greenhouse Effect (GHE) is the process by which specific gases in Earth's atmosphere absorb and re-emit infrared radiation, leading to the warming of the lower atmosphere and the planet's surface.
• GHE is a natural phenomenon essential for life on Earth.
• Without the natural GHE, Earth's average surface temperature would be approximately -18°C.
• Naturally occurring greenhouse gases (GHGs) contribute to an average Earth temperature of about 15°C, making the planet warmer by approximately 33°C.
• Incoming solar radiation (shortwave) predominantly passes through the atmosphere to Earth's surface.
• Earth's surface absorbs solar radiation and reemits it as longwave infrared (IR) radiation.
• Greenhouse Gases (GHGs) in the atmosphere absorb a significant portion of this outgoing longwave terrestrial IR radiation and re-emit it in all directions, including back towards Earth's surface, trapping heat.
• This mechanism is analogous to a glasshouse: shorter wavelength solar radiation from the Sun can enter, but longer wavelength IR emitted from inside (ground/ plants) is largely prevented from escaping through the glass.
• Nitrogen (N2) and Oxygen (O2) are poor absorbers of both shortwave solar and longwave terrestrial radiation and are not greenhouse gases.
• Clouds are good absorbers of Earth's longwave radiation.
• The atmosphere is heated more by the absorption of terrestrial (longwave) radiation by GHGs than directly by incoming solar (shortwave) radiation.
• More than 70% of the atmospheric radiant energy is directed back to the surface, contributing to the warming.
• Major natural GHGs include Water Vapour (H2O), Carbon Dioxide (CO2), Methane (CH4), Nitrous Oxide (N2O), and Ozone (O3).
• Carbon dioxide absorbs strongly in the infrared region, thereby decreasing the loss of heat from Earth by radiation.
• The optimum concentration of carbon dioxide for natural balance in the atmosphere has historically been considered around 0.03 percent.
• The concept of the Greenhouse Effect was first postulated by Joseph Fourier in 1824.

Evidence and Indicators of Climate Change (e.g., global warming, sea-level rise, glacier melt)

• Global surface temperature was 1.09°C higher in 2011–2020 than in 1850–1900. The increase is larger over land (1.59°C) than over the ocean (0.88°C).
• The average increase in Earth's temperature during the last century (approx. 1900-2000)
• World Meteorological Organization's (WMO) "State of the Global Climate 2021 report" stated that the last seven years (2015-2021) were the warmest on record. This increase is mainly due to increased atmospheric greenhouse gas concentrations.
• The top 2000-meter layer of the ocean reached record high temperatures in 2020, and ocean heat content continued to increase, reaching a new record in 2021.
• Global warming has resulted in an increase in sea levels. Estimates suggest approximately 30 cm sea level rise by 2100.
• Causes of sea level rise include the thermal expansion of ocean water and the melting of glaciers and polar ice caps.
• Most glaciers in different parts of the world are retreating. Half of the glaciers on the UNESCO World Heritage list are under threat.
• The Batagaika Crater, located in Siberia, Russia, is a permafrost mega-slump. This region is a focal point for studying climate change effects on permafrost. The thawing permafrost releases enormous quantities of organic carbon (CO2 and methane).
• Impacts of global warming include: rise in sea levels, melting of glaciers, changes in weather conditions (e.g., more intense storms/hurricanes), spread of diseases (e.g., malaria), bleaching of coral reefs, species migration/extinction, and reduced agricultural productivity.
• The frequency and effect of El Niño are increasing.
• Indonesia announced plans to change its capital from Jakarta due to threats from sea level rise and sinking.
• Carbon dioxide measurements, forming the basis of present global warming data (Keeling Curve), have been taken since 1958 at the Mauna Loa Observatory.
• Global Dimming refers to a fall of temperature due to increased atmospheric particulates (aerosols) reflecting sunlight.
• The Global Climate Risk Index is published by the environmental think tank Germanwatch. India ranked 5th in the list of most climate-affected nations in 2018 (as per the 2020 report).
• Ministry of Earth Sciences (MoES) released a report titled ‘Assessment of Climate Change over the Indian Region’, which is the first comprehensive attempt to document and assess climate change in India, highlighting observed/projected changes, impacts, and policy actions. The Indian Institute of Tropical Meteorology (IITM) is located in Pune.
• For India, the year 2020 was the eighth warmest year on record since 1901. 12 out of 15 warmest years were during 2006-2020, and the past decade (2001-2010/2010-2020) was the warmest decade on record. Monsoon season rainfall over the country as a whole was above normal in 2020.
• Albedo values (reflectivity) of ecosystems, in decreasing order, are typically: Tundra > Taiga > Tropical Deciduous > Tropical Evergreen.
• Climate change is a major global political issue due to its widespread impacts.

Extreme Weather Events and Climate Variability

• Extra-tropical cyclones develop in mid/high latitudes, possess a clear frontal system, affect large areas, and can originate over both land and sea.
• Global Drought Snapshot (Dec 2023, COP-28): 1.84 billion people experienced drought effects, with 4.7% facing severe/ extreme conditions. 23 countries declared drought emergencies.
• El Niño Effects:
• Distorts equatorial atmospheric circulation (e.g., Walker Circulation).
• Weakens/reverses trade winds in the central and eastern Pacific.
• Causes irregularities in sea water evaporation.
• Reduces plankton, leading to decreased fish populations due to warmer waters and reduced upwelling.
• Is a significant factor in global warming via interannual variability.
• Causes abnormal weather patterns worldwide, including floods and droughts (e.g., 1997 Indonesian forest fires).
• Is defined as an abnormal weather pattern caused by the warming of the Pacific Ocean near the equator.
• La Niña: Characterized by cooler than normal sea surface temperatures (SSTs) in the central Pacific Ocean.
• Climate Change & Extreme Events: Global warming increases the frequency and severity of extreme weather events such as cyclones, storms, and hurricanes. Tropical cyclones are particularly influenced by climate change.
• Kedar Valley Disaster (June 2013): Caused by heavy rains in the catchment area of the Mandakini River.
• Lightning Deaths in India (2021-2022, IMD/ CROPC Data): States with highest fatalities included Bihar, Madhya Pradesh, Uttar Pradesh, Odisha, West Bengal, and Rajasthan. (Specific order among the listed states for 2021-22 was Bihar > Madhya Pradesh > Odisha > West Bengal > Rajasthan).
• Cyclone Intensities (2021, IMD Classification):
• TAUKTAE: Extremely Severe Cyclonic Storm (ESCS).
• YAAS: Very Severe Cyclonic Storm (VSCS).
• SHAHEEN: Severe Cyclonic Storm (SCS).
• GULAB: Cyclonic Storm (CS).
• Factors Responsible for Climate Change:
• Natural Factors: Sun Spots (solar variability), El Niño and La Niña (natural climate variability).
• External Forcings: Phenomena in Outer Space (e.g., variations in solar output, cosmic rays).
• Anthropogenic Factors: Greenhouse gas emissions, deforestation, land-use changes (not explicitly covered by MCQs, but important for context).

Impacts of Climate Change on Ecosystems and Biodiversity

• Climate change and rising sea levels threaten major ecosystems and species globally.
• Sundarbans (Bangladesh/India): World's largest mangrove forest (10,000 sq km), crucial Bengal tiger habitat; at high risk from climate change and sea-level rise (UN report, May 7, 2019).
• Species Loss (UN, 2019): Approximately 500,000 land species face survival threats due to natural habitat loss exacerbated by climate change.
• Impacts of +2°C Global Temperature Rise:
• Increased annual flooding.
• Spread of insect-borne diseases (e.g., Malaria).
• Shift in agricultural regions.
• Extinction of numerous plant and animal species.
• Warming Rivers: Primarily causes changes in fish migration patterns.
• Regional Climate Change Impacts:
• Bush fires: Australia – USA.
• Locust swarming: Africa – Middle East.
• Heat waves: Antarctica (referring to unusual warming events impacting the region).
• Permafrost melt: Arctic.
• Coral Bleaching (Andaman & Nicobar): Catastrophic coral bleaching and mass coral deaths caused by a 2°C temperature increase in the Indian Ocean.
• Impacts of >3°C Global Temperature Rise (above pre-industrial):
• Terrestrial biosphere tends toward a net carbon source (releases more carbon than it absorbs).
• Widespread coral mortality will occur globally.
• Climate Change & Diseases (WHO, 2008): World Health Organisation report identified 25 diseases linked to climate change.

Impacts on Agriculture, Food Security, and Water Resources

• Agriculture is the human activity most directly and significantly impacted by climate changes.
• Climate change alters temperature, precipitation patterns, atmospheric CO2 levels, and increases the frequency/intensity of extreme weather events, directly impacting crop yields, growing seasons, and pest dynamics.
• Climate change severely impacts food security, leading to reduced agricultural productivity, crop failures, supply chain disruptions, and increased food prices.
• The United Nations has warned that Madagascar has experienced famine-like conditions directly attributed to climate change.
• Increased frequency and intensity of extreme weather events (e.g., droughts, floods, heatwaves) have serious repercussions on food security.
• Food insecurity, coupled with water scarcity and livelihood loss due to climate change, contributes to increased social tension and potential displacement.
• Impacts on water resources include altered precipitation patterns (leading to increased droughts/floods), accelerated glacier melt affecting river flows, and saltwater intrusion in coastal aquifers.

Intergovernmental Panel on Climate Change (IPCC) Assessments and Projections

• The Intergovernmental Panel on Climate Change (IPCC) was established in 1988.
• IPCC's 4th Assessment Report (AR4) states that the average sea level rose approximately at a rate of 1.8 mm per year during the period 1961-2003.
• The IPCC emphasizes the essential need for deep, rapid, and sustained reductions in Greenhouse Gas (GHG) emissions.

International Conventions and Agreements on Climate Change (e.g., UNFCCC, Kyoto Protocol, Paris Agreement)

• United Nations Framework Convention on Climate Change (UNFCCC):
• Objective: Stabilize greenhouse gas (GHG) concentrations to prevent dangerous anthropogenic interference with the climate system. Deals with greenhouse gases emissions mitigation.
• Adopted: May 9, 1992 (Rio Earth Summit 1992).
• Entered into force: March 21, 1994.
• Treaty acts as a framework for international cooperation to combat climate change.
• Principle of "Common But Differentiated Responsibilities and Respective Capabilities" (CBDR-RC) applies to GHG emissions reduction.
• Kyoto Protocol (Under UNFCCC):
• Adopted: December 1997, at COP3 in Kyoto, Japan.
• Objective: Commits industrialized countries (Annex I Parties) and economies in transition to reduce GHG emissions.
• First Commitment Period (2008-2012) targeted reduction of 6 main GHGs: Carbon Dioxide (CO2), Methane (CH4), Nitrous Oxide (N2O), Hydrofluorocarbons (HFCs), Perfluorocarbons (PFCs), and Sulphur Hexafluoride (SF6).
• Mechanisms:
• Carbon Credit: Originated from Kyoto Protocol.
• Clean Development Mechanism (CDM): Allows Annex I countries to earn Certified Emission Reductions (CERs) from GHG reduction projects in developing countries.
• Joint Implementation (JI), Emissions Trading.
• Annex I countries: Developed countries and economies in transition with emission reduction targets.
• Annex B countries: Annex I countries with specific emission reduction commitments.
• Paris Agreement (Under UNFCCC):
• Adopted: December 12, 2015, at COP21 in Paris, France.
• Objective: Limit global warming to "well below 2.0 °C" above pre-industrial levels, and pursue efforts to limit the increase to 1.5 °C.
• Entered into force: November 4, 2016, after at least 55 UNFCCC parties accounting for at least 55% of global GHG emissions ratified it.
• Mechanism: Nationally Determined Contributions (NDCs) (evolved from Intended Nationally Determined Contributions - INDCs). Countries outline their climate actions; these are not legally binding in terms of targets but legally binding in terms of communicating and reporting.
• Balance: Recognizes developing countries' right to development; balances mitigation, adaptation, and finance/ support.
• Global Stocktake: Central outcome of COP28, assesses collective progress towards Paris Agreement goals.
• Developed countries committed to mobilizing $100 billion per year by 2020 for developing countries (not $1000 billion).
• Key Climate Conferences (COPs):
• COP3 (1997): Kyoto, Japan (Kyoto Protocol adopted).
• COP15 (2009): Copenhagen, Denmark (Copenhagen Accord).
• COP17 (2011): Durban, South Africa (Green Climate Fund established).
• COP21 (2015): Paris, France (Paris Agreement adopted).
• COP24 (2018): Katowice, Poland.
• COP26 (2021): Glasgow, UK.
• COP27 (2022): Sharm El-Sheikh, Egypt.
• COP28 (2023): Dubai, UAE (Global Stocktake, "transitioning away from fossil fuels" to achieve net zero by 2050).
• COP29 (2024): Baku, Azerbaijan.
• COP30 (2025): Belem, Brazil.
• Related International Agreements/Initiatives:
• Montreal Protocol (1987): International treaty to protect the ozone layer by phasing out the production of ozonedepleting substances (ODS) like Chlorofluorocarbons (CFCs). Indirectly benefits climate by phasing out substances that are also potent GHGs.
• Kigali Amendment (2016): An amendment to the Montreal Protocol to phasedown Hydrofluorocarbons (HFCs), which are potent greenhouse gases, though not ozone-depleting.
• Green Climate Fund (GCF): Established at COP17 in Durban (2011) under the UNFCCC. Intends to assist developing countries in adaptation and mitigation practices; developed nations provide the fund. Became fully operational with first projects approved in 2015.
• Global Campaign '350': International Day for Climate Action observed on October 24, 2009, highlighting the 350 ppm CO2 atmospheric concentration safe limit.
• Marrakech Partnership: Collaboration between governments and non-state stakeholders (cities, businesses, investors) for global climate action, guided by the 2030 Agenda for Sustainable Development.
• Race to Zero Campaign: Aims to build momentum around the shift to a decarbonized economy, rallying non-state actors for a healthy, resilient, zerocarbon future. Not related to Zero-Sum Game.
• One Planet City Challenge (OPCC): An initiative of WWF (World Wide Fund for Nature) that invites cities to report innovative climate actions.
• Climate Neutral Now: Initiative launched by the UNFCCC Secretariat. Encourages organizations and stakeholders to act now to achieve a carbonneutral world by 2050, deriving its aims from the Paris Agreement.
• Talanoa Dialogue: Related to the UN Climate Change Talks, a facilitative dialogue for parties to share experiences and build trust regarding NDCs.
• Climate and Clean Air Coalition (CCAC): Focuses on reducing ShortLived Climate Pollutants (SLCPs) like methane, black carbon, and HFCs. Not a G20 initiative.
• Global Alliance for Climate-Smart Agriculture (GACSA): Launched at the UN Climate Summit 2014. Membership is voluntary and does not create binding obligations.
• Climate Action Tracker: A database created by a coalition of research organizations (Climate Analytics, NewClimate Institute, Ecofys) that monitors emission reduction pledges and climate actions of different countries.
• The Climate Group: An international non-profit organization driving climate action. Launched "EP100" with the International Energy Agency (IEA), bringing companies committed to energy efficiency. The Climate Group is the secretariat to the "Under2 Coalition".
• Basel Convention: Deals with the control of transboundary movements of hazardous wastes and their disposal, not primarily focused on GHG emissions.
• India's Commitments at COP26 (Glasgow, 2021):
• Reach Net-Zero emissions by 2070.
• Reduce carbon emissions by 1 billion tons by 2030.
• Increase non-fossil energy capacity to 500 GW by 2030.
• Meet 50% of its total energy requirement by renewable energy by 2030.
• World Meteorological Organization (WMO): Headquarters in Geneva.
• Asia Pacific Partnership (APP) on Clean Development and Climate: Accounted for a significant portion of world's population, energy consumption, and GHG emissions; intended to complement Kyoto Protocol through voluntary actions.

National Action Plan on Climate Change (NAPCC) and India's Climate Policies

• National Action Plan on Climate Change (NAPCC):
• Released in 2008.
• Aims to address mitigation and adaptation strategies for climate change.
• Emphasizes maintaining a high growth rate to raise living standards and reduce vulnerability to climate change.
• Comprises 8 core national missions.
• First mission operationalized: National Solar Mission (NSM).
• 8 Core Missions: National Solar Mission 1. National Mission for Enhanced 2. Energy Efficiency National Mission on Sustainable 3. Habitat National Water Mission 4. National Mission for Sustaining 5. the Himalayan Ecosystem (supports Himalayan glacial monitoring) National Mission for a Green 6. India (aims to restore/enhance forest cover, respond to climate change via adaptation/mitigation) National Mission for Sustain7. able Agriculture National Mission on Strategic 8. Knowledge for Climate Change
• Not a Mission under NAPCC: National Mission for Sustainable Urban Ecosystem.
• Goals/Recommendations: Promote solar energy, reduce energy consumption (focus on demand-side), afforestation of degraded forest lands, improve water-use efficiency. Its broad scope covers themes like waste-to-energy, coastal areas, wind energy, and climate change & health.
• India's Climate Policies & Targets:
• National Adaptation Fund for Climate Change (NAFCC):
• Meant to assist national and State level activities for adaptation measures.
• Taken as a Central Sector Scheme.
• In force since 2015-2016.
• Initial corpus: Rs. 100 crores.
• National Implementing Entity: NABARD (National Bank for Agriculture and Rural Development).
• Temperature Change in India:
• Mean surface air temperature increased by 0.8 °C over the past century.
• Average temperature increased by about 0.7°C since 1901.
• India's Nationally Determined Contributions (NDCs) / Panchamrit Targets (COP26, Glasgow, 2021):
• Related to Climate Change.
• 5 Nectar Elements (Panchamrit): Reach 500 GW non-fossil 1. energy capacity by 2030. Meet 50 percent of its en2. ergy requirements from renewable energy by 2030. Reduce total projected 3. carbon emissions by one billion tonnes from now till 2030. Reduce the carbon intens4. ity of its economy by 45 percent by 2030 over 2005 levels. (Earlier committed 33-35% by 2030). Achieve the target of Net 5. Zero Emissions by 2070.
• Long-Term Low Emission Development Strategy (LT-LEDS): Differentiated from NAPCC as it provides sector-specific deep decarbonization roadmaps.
• Climate Change Performance Index (CCPI) 2023:
• India ranked 8th (climbed 2 spots).
• India is amongst the top 10 best performing countries.
• India is placed higher in rank than Norway and United Kingdom.
• India Climate Change Knowledge Portal: Launched in November 2020.
• First Carbon Free State of India: Himachal Pradesh.
• Global GHG Emissions: India is the 3rd largest emitter globally. India's share in world GHG emissions is approximately 5% (referencing available MCQ options).
• Clean Development Mechanism (CDM): Established in India to combat climate change.
• Other related facts:
• USA unveiled a National Plan to reduce 80% GHG emissions by 2050.
• Climate-Smart Village approach in India is part of a project led by the Climate Change, Agriculture and Food Security (CCAFS), an international research program.
• CCAFS project is carried out under Consultative Group on International Agricultural Research (CGIAR), headquartered in France.
• The International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) in India is one of CGIAR's research centres.

Ocean Acidification and its Consequences

• Ocean Acidification (OA) is the ongoing decrease in the pH of the Earth's oceans.
• Primary cause: Oceans absorb a significant portion (~30%) of the atmospheric anthropogenic carbon dioxide (CO₂) emissions.
• Process: Dissolved CO₂ reacts with seawater to form carbonic acid (H₂CO₃), which then dissociates, releasing hydrogen ions (H⁺) and lowering the pH.
• Consequence: Increased H⁺ ions reduce the availability of carbonate ions (CO₃²⁻).
• Impact on marine life: Carbonate ions are crucial for calcifying organisms (e.g., corals, mollusks like oysters and mussels, pteropods, plankton) to build and maintain their shells and skeletons. Reduced availability impairs calcification.
• Further impact: Existing shells and skeletons can dissolve in increasingly acidic water.
• Ecosystem impact: Disrupts marine food webs and can lead to a decrease in overall ocean productivity.
• Ocean warming, a distinct but related aspect of climate change, increases the frequency and intensity of tropical cyclone winds and rainfall.
• OA also affects non-calcifying organisms, impacting fish behavior, metabolism, and immune responses.

5. Ozone Layer

Vulnerability, Adaptation Strategies, and Climate Resilience

• Vulnerability: Susceptibility to harm from climate change impacts; a function of exposure, sensitivity, and adaptive capacity.
• Adaptation Strategies: Actions taken to adjust to actual or expected climate change and its effects, reducing harm or exploiting beneficial opportunities.
• Types of Adaptation:
• Ecosystem-based Adaptation (EbA): Uses biodiversity and ecosystem services as part of an overall adaptation strategy.
• Community-based Adaptation (CBA): Locally led, bottom-up approach focusing on community-specific vulnerabilities.
• Technological Adaptation: Development and deployment of new technologies (e.g., drought-resistant crops, early warning systems).
• Infrastructure/Structural Adaptation: Building sea walls, improved drainage systems, climate-resilient housing.
• Policy/Institutional Adaptation: Changing regulations, land-use planning, insurance schemes.
• Adaptation Gap Report: Annually published by the UNEP (United Nations Environment Programme).
• Adaptation Gap Report 2022: Released by UNEP, highlighting the gap between global adaptation needs and current implementation/ financing.
• Climate Resilience: The capacity of social, economic, and environmental systems to cope with a hazardous event or trend or disturbance, responding or reorganizing in ways that maintain their essential function, identity, and structure, while also maintaining the capacity for adaptation, learning, and transformation.

Practice MCQs: Greenhouse Effect and Climate Change

Anthropogenic (Human-induced) Enhanced Greenhouse Effect

1. As compared to natural greenhouse effect, the enhanced greenhouse effect refers to increase in average surface temperature of the Earth due to

   Asked in: UPSC Geoscientist 2022 · UPPCS Prelims 2015

   1. volcanic activity
   2. warm ocean currents
   3. sunspot activity
   4. anthropogenic activities
   Show answer

   Answer: D. anthropogenic activities

   The natural greenhouse effect is a process where certain gases in the atmosphere trap heat, warming the Earth's surface to a habitable temperature. The enhanced, or anthropogenic, greenhouse effect refers to the additional warming of the Earth's surface and lower atmosphere due to the increase in greenhouse gas concentrations caused by human activities, primarily the burning of fossil fuels, deforestation, and industrial processes. D. Maintenance of ecosystem Ans: D Biodiversity contributes to ecosystem services such as pollination, soil formation, climate regulation, nutrient cycling, and pest control, which are vital for human survival and well-being.

2. Read the following statements about the climate change. Identify the correct ones. 1. As per the latest report of IPCC, Climate Change is happening at a rapid pace. 2. The role of anthropogenic activities are extremely likely responsible for the climate change. 3. Change in Climate would promote insect-borne diseases and lead to shift in climatic boundaries.

   Asked in: GPSC Prelims CSP 2 2023

   1. 1 and 2 only
   2. 2 and 3 only
   3. 1, 2 and 3
   4. 1 only
   Show answer

   Answer: C. 1, 2 and 3

3. IPCC reports consistently indicate that climate change is occurring at an unprecedented and accelerating rate, making statement 1 correct. 2. The Intergovernmental Panel on Climate Change (IPCC) reports unequivocally state that human activities, primarily the emission of greenhouse gases, are the dominant cause of observed warming since the mid-20th century, making statement 2 correct. The language used in the latest reports is very strong ("unequivocal" or "extremely likely"). 3. Climate change is projected to alter temperature and precipitation patterns, which can expand the geographical range and seasonality of many disease vectors (like mosquitoes and ticks), thus potentially promoting insect-borne diseases (e.g., malaria, dengue). It also causes shifts in climatic zones and biomes, leading to shifts in climatic boundaries, making statement 3 correct. 3. At present which country is the maximum emitter of carbon dioxide ?

   Asked in: HPPSC HPAS Prelims 2014

   1. USA
   2. China
   3. Russia
   4. France
   Show answer

   Answer: B. China

   China surpassed the United States as the largest annual emitter of CO2 in the mid-2000s due to its rapid economic growth and heavy reliance on fossil fuels, particularly coal.

4. Which country is currently the largest emitter of carbon dioxide?

   Asked in: HPPSC HPAS Prelims 2014

   1. U.S.A. (America)
   2. China
   3. Russia
   4. France
   Show answer

   Answer: B. China

   - China surpassed the U.S. as the largest emitter in the mid-2000s. - Its large population, rapid industrialization, and heavy reliance on coal power contribute significantly to its high emissions.

5. The impact of humans on global climate has been induced by which of the following ? a. Deforestation since 8000 years b. Use of fire and overgrazing c. Wet paddy cultivation since 5000 years d. Industrial revolution

   Asked in: MPSC CS Prelims 2018

   1. Only d
   2. Only c and d
   3. Only b, c and d
   4. All of the above
   Show answer

   Answer: D. All of the above

   Human activities like land-use change (deforestation, agriculture), resource use (fire), and industrial processes have altered the Earth's climate over various timescales.

6. Which of the following are the primary causes of climate change? Excessive burning of fossil fuels Exploding numbers of automobiles driven by oil Increasing solar flares Heavy deforestation Select the correct answer using the code given below:

   Asked in: UPPCS Prelims 2017

   1. 2 and 3 only
   2. 1, 2 and 4 only
   3. 1, 2, 3 and 4
   4. 1 and 4 only
   Show answer

   Answer: B. 1, 2 and 4 only

   Human activities that release large amounts of greenhouse gases (GHGs) into the atmosphere are the main drivers of the current accelerated climate change. Burning fossil fuels (coal, oil, and natural gas) for energy production, transportation (automobiles), and industry releases significant amounts of CO2 and other GHGs (1, 2). Deforestation reduces the absorption of CO2 by plants and can release stored carbon, further increasing atmospheric GHG concentrations (4).

Carbon Footprint, Carbon Sequestration, and Carbon Pricing Mechanisms

7. What is 'Greenhouse Gas Protocol'?

   Asked in: APSC CCE Prelims Exam 2023 · UPSC IAS 2016

   1. It is an international accounting tool for government and business leaders to understand, quantify, and manage greenhouse gas emissions
   2. It is an initiative of the United Nations to offer financial incentives to developing countries to reduce greenhouse gas emissions and to adopt eco-friendly technologies
   3. It is an inter-governmental agreement ratified by all the member countries of the United Nations to reduce greenhouse gas emissions to specified levels by the year 2030
   4. It is one of the multi-lateral REDD+ initiatives hosted by the World Bank
   Show answer

   Answer: A. It is an international accounting tool for government and business leaders to understand, quantify, and manage greenhouse gas emissions

   - GHG Protocol provides standards for GHG accounting and reporting. - It is widely used by corporations, governments, and NGOs. - It helps organizations measure their carbon footprint. - It is a framework, not a treaty or a funding mechanism.

8. One carbon credit is accepted as equivalent to

   Asked in: UPSC CDS 2 2017

   1. 100 kg of carbon
   2. 100 kg of carbon dioxide
   3. 1000 kg of carbon
   4. 1000 kg of carbon dioxide
   Show answer

   Answer: D. 1000 kg of carbon dioxide

   Carbon credits represent a measurable amount of greenhouse gas emissions reduced, avoided, or sequestered, standardized to 1 tonne of CO2 equivalent.

9. The use of carbon tax has been very successful to reduce emissions of greenhouse gases in :

   Asked in: HPPSC HPAS Prelims 2016

   1. The United States of America
   2. China
   3. Sweden
   4. Australia
   Show answer

   Answer: C. Sweden

   Sweden implemented a carbon tax in 1991 and has progressively increased it over the years. This policy is widely regarded as one of the most successful examples of using a carbon tax to significantly reduce greenhouse gas emissions while maintaining economic growth.

10. As per the World Resources Institute (2011) which of the following countries is the world's highest carbon emitter ?

    Asked in: MPSC CS Prelims 2016

    1. U.S.A.
    2. Russia
    3. India
    4. China
    Show answer

    Answer: D. China

    According to the World Resources Institute data for 2011 (and subsequent years), China was the world's largest emitter of carbon dioxide (CO2), surpassing the United States in this regard several years prior.

11. What is carbon credit ?

    Asked in: OPSC CS Prelims 2016

    1. It is the difference between the carbon emis‐ sion allowed and actually emitted carbon
    2. It is the loan amount by IMF for reducing pol‐ lution
    3. It is loan given to poor people for buying Modern Stoves
    4. It is the fine amount imposed for excess emission of carbon dioxide
    Show answer

    Answer: A. It is the difference between the carbon emis‐ sion allowed and actually emitted carbon

    A carbon credit is a tradable permit or certificate that allows the holder to emit one tonne of carbon dioxide or an equivalent amount of other greenhouse gases. It is fundamentally related to cap-and- trade schemes, where an entity is allocated a certain allowance of emissions (carbon emission allowed). If the entity emits less than this allowance (actually emitted carbon), the difference constitutes surplus credits that can be sold or banked.

12. The highest per capita emitter of carbon dioxide in the world is :

    Asked in: OPSC CS Prelims 2016

    1. US
    2. Singapore
    3. Qatar
    4. Saudi Arabia
    Show answer

    Answer: C. Qatar

    - Per capita CO₂ emissions are calculated by dividing a country's total CO₂ emissions by its population. - Countries with high per capita emissions are often wealthy nations with high energy consumption or major fossil fuel producers with relatively small populations. - While large economies like the US have high total emissions, their per capita emissions are typically lower than the top per capita emitters like Qatar or some other Gulf nations.

Climate Change Mitigation Strategies (e.g., renewable energy, carbon capture, afforestation)

13. Consider the following statements regarding net-zero emission. Net-zero emission means country would bring down its greenhouse gas emissions to near zero. Countries are setting their Net-zero emission goal based on the 2015 Paris Agreement guidelines. Net-zero emission can be achieved by creating more carbon sinks such as forests and relying on futuristic technologies such as carbon capture and storage. Which of the above statement/s is/are correct?

    Asked in: GPSC Prelims CSP 2 2024

    1. 2, 3
    2. 1, 3
    3. 3 only
    4. 1, 2, 3
    Show answer

    Answer: A. 2, 3

    - Statement 1: Net-zero means emissions are balanced by removals. While significant emission reduction is necessary, the definition is about the balance, not necessarily reducing gross emissions to near zero before removals. - Statement 2: The Paris Agreement's goal of limiting global warming implies the need for global net-zero emissions around mid-century. Countries' individual net-zero goals are a response to this global imperative established by the PA. - Statement 3: Enhancing carbon sinks (like forests) and deploying carbon capture and storage technologies are principal strategies for removing CO2 from the atmosphere to balance residual emissions and achieve net-zero.

14. According to Kigali Amendment of 2016, the world can avoid up to ______ of global warming by the end of the century.

    Asked in: GPSC Prelims CSP 2 2017

    1. 0.5° C
    2. 0.25° C
    3. 1° C
    4. 2° C
    Show answer

    Answer: A. 0.5° C

    HFCs are powerful greenhouse gases with a high global warming potential, primarily used as refrigerants and propellants.

15. Recently 'Decarbonising Transport in India' project was launched by NITI Aayog in collaboration with International Transport Forum (ITF). Identify the incorrect statement.

    Asked in: PPSC CS Prelims 2021

    1. It aims to develop a pathway towards a low carbon transport system for India.
    2. The project will design a tailor-made transport emissions assessment framework for India.
    3. India, Azerbaijan, Nigeria and Morocco are the participants of the Decarbonising Transport in Emerging Economies (DTEE).
    4. None of the above
    Show answer

    Answer: D. None of the above

    - Statement A is correct: The 'Decarbonising Transport in India' project, a collaboration between NITI Aayog and ITF, explicitly aims to develop a pathway towards a low-carbon transport system in India, aligning with climate goals. - Statement B is correct: The project focuses on creating a specific transport emissions assessment framework tailored to the Indian context, considering its unique challenges and opportunities. - Statement C is correct: India is indeed one of the four core focus countries (alongside Azerbaijan, Morocco, and Nigeria) under the ITF's Decarbonising Transport in Emerging Economies (DTEE) project, within which the India-specific initiative is undertaken.

16. The United Nations Environment Programme and International Energy Agency jointly released a 'Cooling Emissions and Policy Synthesis Report' (CEPSR). Which of the following statements is/are correct about the report ?

    Asked in: PPSC CS Prelims 2021

    1. Only 1
    2. Only 2
    3. Both 1 and 2
    4. Neither 1 nor 2
    Show answer

    Answer: C. Both 1 and 2

    It is based on assessment of development and climate benefits of efficient and climate-friendly cooling. It lays out actions that can be taken to deliver efficient and climate-friendly cooling for all. Select the correct answer using the code given below : - Statement 1 is correct: The 'Cooling Emissions and Policy Synthesis Report' (CEPSR) is indeed based on assessing the significant development benefits (e.g., health, productivity) and climate benefits (e.g., reduced GHG emissions) that arise from adopting efficient and climate-friendly cooling technologies and practices. - Statement 2 is correct: As a 'Policy Synthesis Report', a core function is to outline concrete actions, strategies, and policies that governments, industries, and other stakeholders can implement to accelerate the transition towards efficient and climate-friendly cooling solutions accessible to all.

17. With reference to 'NET-ZERO' goal for 2050, which of the following statements is/are correct? 1. It means that a country will bring down its emissions to zero by 2050. 2. It means that a country's emissions will be compensated by absorption and removal of green house gases from the atmosphere. Select the correct answer using the codes given below:

    Asked in: UPPCS Prelims 2021

    1. Only 1
    2. Only 2
    3. Both 1 and 2
    4. Neither 1 nor 2
    Show answer

    Answer: B. Only 2

    Statement 1 is incorrect. Achieving 'Net-Zero' emissions does not mean bringing emissions down to absolute zero. It means achieving a balance between anthropogenic emissions of greenhouse gases (GHGs) and their removal from the atmosphere. Statement 2 correctly describes this balance: emissions are offset by absorption and removal.

18. Consider the following statements regarding ‘Earth Hour’ : 1. It is an initiative of UNEP and UN‐ ESCO. 2. It is a movement in which the participants switch off the lights for one hour on a certain day every year. 3. It is a movement to raise the awareness about the climate change and the need to save the planet. Which of the statements given above is/are correct?

    Asked in: UPSC IAS 2014

    1. 1 and 3 only
    2. 2 only
    3. 2 and 3 only
    4. 1, 2 and 3
    Show answer

    Answer: C. 2 and 3 only

    - Earth Hour is a global environmental movement. - It is organized by WWF and involves switching off non-essential lights and electrical appliances for one hour. - The goal is to encourage individuals, communities, and businesses to take action for the environment and demonstrate commitment to the planet.

Climate Feedback Loops and Tipping Points

19. If the Arctic ice is replaced with dense forest, which of the following situations may arise ?

    Asked in: APSC CCE Prelims Exam 2013

    1. It Will decelerate global warming
    2. It will accelerate global warming
    3. It may or may not affect global warming
    4. It will accelerate global warming
    Show answer

    Answer: B. It will accelerate global warming

    Replacing a highly reflective surface with a highly absorptive surface leads to increased absorption of solar energy by the Earth's surface, directly causing warming. While forests do absorb carbon dioxide (a greenhouse gas), the positive feedback loop from the albedo change in a region like the Arctic would likely outweigh the carbon sequestration effect in terms of immediate local and regional warming.

20. Which of the following is a potential tipping point of global climate change ?

    Asked in: APPSC Group II Mains paper 2 2025

    1. Loss of Arctic ice
    2. Reduction in CO2 emissions
    3. Increased deforestation
    4. Decrease in solar radiation
    Show answer

    Answer: A. Loss of Arctic ice

    A climate tipping point is a critical threshold beyond which a system reorganises itself, often abruptly and/or irreversibly. The loss of large ice sheets (like Greenland or parts of Antarctica) or Arctic sea ice can trigger positive feedback loops (e.g., reduced albedo leading to more warming) that accelerate climate change.

Composition, Sources, and Radiative Forcing of Major Greenhouse Gases (GHGs)

21. Paddy fields are chief sources of which of the following greenhouse gases? (i) Methane (ii) Carbon dioxide (iii) Nitrous oxide (iv) Ozone Select the correct answer using the codes given below.

    Asked in: APSC CCE Prelims Exam 2023

    1. (i) only
    2. (ii) only
    3. (i) and (iii) only
    4. (ii), (iii) and (iv) only
    Show answer

    Answer: C. (i) and (iii) only

    - Waterlogged conditions in paddy fields lead to anaerobic decomposition. - Anaerobic decomposition produces methane (CH4). - Nitrogen cycling in paddy fields can lead to nitrous oxide (N2O) emissions. - Methane and Nitrous oxide are significant greenhouse gases.

22. The main component of greenhouse gases is

    Asked in: BPSC Prelims Exam 64th

    1. carbon dioxide
    2. methane
    3. nitrous oxide
    4. ozone
    Show answer

    Answer: A. carbon dioxide

    BPSC Prelims Exam-65th While water vapor is the most abundant greenhouse gas overall, among the long-lived, well-mixed greenhouse gases significantly influenced by human activities, carbon dioxide (CO2) is the most significant contributor to the enhanced greenhouse effect and global warming.

23. Which gas contributes to global warming through its greenhouse effect?

    Asked in: BPSC Prelims Exam 68th

    1. Nitrous oxide
    2. Methane
    3. Carbon dioxide
    4. More than one of the above
    Show answer

    Answer: D. More than one of the above

    Greenhouse gases trap heat in the Earth's atmosphere, leading to the greenhouse effect and contributing to the rise in global average temperatures.

24. Which greenhouse gas has maximum average residence time in the atmosphere?

    Asked in: UPSC CDS 1 2024

    1. CFC
    2. CH₄
    3. N₂O
    4. Water vapour
    Show answer

    Answer: A. CFC

    Greenhouse gases have varying residence times in the atmosphere. Among the options provided, Chlorofluorocarbons (CFCs) have the longest average residence times, typically ranging from decades to several centuries.

25. The situation of global warming in atmosphere is developed due to increase in which gas ?

    Asked in: CGPSC Prelims Exam 2012

    1. Oxygen
    2. Carbondioxide
    3. Hydrogen
    4. Nitrogen
    Show answer

    Answer: B. Carbondioxide

    Greenhouse gases trap heat in the Earth's atmosphere, leading to a gradual increase in global temperatures. Human activities, particularly the burning of fossil fuels, have significantly increased the concentration of CO2 and other greenhouse gases since the Industrial Revolution.

26. These days, the atmospheric concentration of CO₂ found in PPM is about

    Asked in: CGPSC Prelims Exam 2012

    1. 250
    2. 300
    3. 360
    4. 400
    Show answer

    Answer: D. 400

    The concentration of atmospheric CO2 has been steadily rising due to anthropogenic emissions, particularly from the burning of fossil fuels, leading to concerns about climate change. Monitoring CO2 levels is crucial for understanding global warming trends.

Definition and Natural Greenhouse Effect

27. The Greenhouse effect deals with :

    Asked in: APPSC Group 1 Prelims 2010

    1. Cooling of lower atmosphere
    2. Warming of upper atmosphere
    3. Cooling of upper atmosphere
    4. Warming of lower atmosphere
    Show answer

    Answer: D. Warming of lower atmosphere

    The Greenhouse effect leads to the warming of the lower atmosphere.

28. Which one of the following statements is true with regard to a greenhouse ?

    Asked in: UPSC CDS 1 2022

    1. The shorter wavelength infrared radiations from the Sun can enter into the greenhouse while longer wavelength infrared radiations from the ground and the plants inside the greenhouse cannot pass back out through the glass.
    2. The shorter wavelength infrared radiations from the Sun can enter into the greenhouse and the longer wavelength infrared radiations from the ground and the plants inside the greenhouse can also pass through the glass.
    3. The shorter wavelength infrared radiations from the Sun cannot enter into the greenhouse while longer wavelength infrared radiations from the ground and the plants inside the greenhouse can pass back out through the glass.
    4. No infrared radiation can pass through the glass of the greenhouse.
    Show answer

    Answer: A. The shorter wavelength infrared radiations from the Sun can enter into the greenhouse while longer wavelength infrared radiations from the ground and the plants inside the greenhouse cannot pass back out through the glass.

    Glass is largely transparent to incoming short- wavelength radiation from the sun (including visible light and some short-wavelength infrared). This radiation warms the interior of the greenhouse (ground, plants, air). The warmed objects then re- emit energy as longer-wavelength infrared radiation (heat). Glass is relatively opaque to this longer- wavelength infrared radiation, trapping the heat inside and causing the temperature to rise. Option A describes this process where shorter wavelengths enter and longer wavelengths cannot easily exit.

29. Greenhouse gases are known so as:

    Asked in: UPSC Geoscientist 2020

    1. they trap heat in the high altitudes.
    2. they act like a greenhouse on the surface of the planet.
    3. the colour of some of the gases emanating from industrial plants are green.
    4. these gases are produced by agricultural crops.
    Show answer

    Answer: B. they act like a greenhouse on the surface of the planet.

    - Greenhouse gases (such as CO₂, methane, water vapor) are transparent to incoming solar radiation (shortwave). - The Earth's surface absorbs this radiation and re-emits energy as infrared radiation (longwave heat). - Greenhouse gases absorb this outgoing infrared radiation and re-emit it in all directions, including back towards the Earth's surface, thus trapping heat and warming the planet.

30. Naturally occurring green house gases keeps the Earth warmer nearly by:

    Asked in: UPSC Geoscientist 2021

    1. 20 °C
    2. 23 °C
    3. 30 °C
    4. 33 °C
    Show answer

    Answer: D. 33 °C

    Without the natural greenhouse effect, Earth's average surface temperature would be about -18°C. With it, the average temperature is around +15°C.

31. Which one of the following is not correct in the context of greenhouse effect?

    Asked in: UPSC Geoscientist 2022

    1. Nitrogen and oxygen are poor absorbers of shortwave solar radiation
    2. Clouds are poor absorbers of the Earth radi‐ ation
    3. The most Earth radiation that escapes to space is in a narrow band from 8-13 micrometres
    4. More than 70% of the atmospheric radiant energy is directed back to the surface
    Show answer

    Answer: B. Clouds are poor absorbers of the Earth radi‐ ation

    - Nitrogen and oxygen (A) are diatomic molecules and are poor absorbers of both incoming solar (shortwave) and outgoing Earth (longwave) radiation, explaining why they are not greenhouse gases. - The atmospheric window (C) is a range of wavelengths (roughly 8-13 µm) in the infrared spectrum where the atmosphere, particularly water vapour and CO2, is relatively transparent, allowing some Earth radiation to escape to space. - A large proportion of atmospheric radiant energy, absorbed from the Earth's surface, is indeed re-emitted downwards as back radiation (D), contributing significantly to surface warming via the greenhouse effect. While the exact percentage can vary, the concept that a large amount is directed back is correct.

32. Carbon dioxide absorbs strongly in infrared region and its presence in atmosphere decreases the loss of heat from earth by radiations. This is called :

    Asked in: HPPSC HPAS Prelims 2010

    1. Carbon dioxide burning
    2. Carbon dioxide recycling
    3. Carbon recycling
    4. Greenhouse effect
    Show answer

    Answer: D. Greenhouse effect

    The Greenhouse effect is the process by which radiation from a planet's atmosphere warms the planet's surface to a temperature above what it would be without its atmosphere. Greenhouse gases, such as carbon dioxide, methane, and water vapour, absorb and re-emit infrared radiation. This process traps heat within the atmosphere, reducing the loss of heat from the Earth by radiation, thus warming the planet.

Evidence and Indicators of Climate Change (e.g., global warming, sea-level rise, glacier melt)

33. Which one of the following is related to global dimming?

    Asked in: UPSC CDS 1 2024

    1. Fall of atmospheric pressure due to increased particulates
    2. Raise of atmospheric pressure due to increased particulates
    3. Raise of temperature due to increased particu‐ lates
    4. Fall of temperature due to increased particu‐ lates
    Show answer

    Answer: D. Fall of temperature due to increased particu‐ lates

    This phenomenon is caused by increased levels of particulate matter (aerosols and pollutants) in the atmosphere. These particles reflect sunlight back into space and absorb solar radiation. They also act as cloud condensation nuclei, leading to brighter and more reflective clouds. By reducing the amount of incoming solar energy, global dimming results in a cooling effect, causing a fall of temperature at the Earth's surface.

34. The broad estimates of sea level rise due to global warming by 2100 is approximately:

    Asked in: UPSC Geoscientist 2020

    1. 10 cm
    2. 20 cm
    3. 30 cm
    4. 40 cm
    Show answer

    Answer: D. 40 cm

    - Sea level rise is caused primarily by the thermal expansion of seawater and the melting of glaciers and ice sheets. - Projections for sea level rise are based on climate models and future greenhouse gas emission scenarios. - The Intergovernmental Panel on Climate Change (IPCC) reports provide detailed projections with associated uncertainty ranges for different scenarios.

35. According to the Global Climate Risk Index 2020, published by environmental think tank Germanwatch, in the year 2018 India's rank in the list of top most climate affected nations is:

    Asked in: UPSC Geoscientist 2020

    1. 1st
    2. 3rd
    3. 5th
    4. 7th
    Show answer

    Answer: C. 5th

    The Global Climate Risk Index analyses the extent to which countries and regions have been affected by the impacts of extreme weather events (storms, floods, heatwaves etc.).

36. Which one of the following statements on Climate of India is NOT correct?

    Asked in: UPSC Geoscientist 2021

    1. Year 2020 was the eighth warmest year on record since 1901
    2. 12 out of 15 warmest years were during the recent fifteen years (2006-2020)
    3. During the year 2020, the monsoon season rainfall over the country as a whole was below normal
    4. Past decade (2001-2010/ 2010-2020) was the warmest decade on record
    Show answer

    Answer: C. During the year 2020, the monsoon season rainfall over the country as a whole was below normal

    - According to the India Meteorological Department (IMD) reports for 2020, the Southwest Monsoon rainfall over the country as a whole was above normal, specifically 109% of the Long Period Average (LPA). - Statement A is correct: IMD data confirmed 2020 was the eighth warmest year on record since 1901. - Statement B is correct: Global and Indian climate trends show that most of the warmest years on record have occurred in recent decades. IMD reports confirm that 12 out of the 15 warmest years during 1901-2020 were in the period 2006-2020. - Statement D is correct: Recent decades, such as 2001-2010 and 2011-2020, have been the warmest decades on record for India, consistent with global warming trends.

37. Which of the following statements are correct regarding World Meteorological Organization’s report titled “State of the Global Climate 2021 report”? 1. According to the report last seven years from 2015 to 2021 are the warmest years 2. This increase in temperature is caused mainly due to the increase in atmospheric greenhouse gas concentrations 3. Top 2000 meter layer of the ocean reached a record high temperature on 2020

    Asked in: GPSC Prelims CSP 2 2022

    1. 1, 2 and 3
    2. 2 and 3 only
    3. 1 and 3 only
    4. 1 and 2 only
    Show answer

    Answer: D. 1 and 2 only

    The WMO's annual State of the Global Climate report provides a summary of climate indicators. The 2021 report highlighted the continued warming trend, confirming that the last seven years (2015-2021) were the warmest on record globally, primarily driven by increasing greenhouse gas concentrations.

38. According to a study by the UN body, how many of the glaciers on the UNESCO World Heritage list are under threat?

    Asked in: GPSC Prelims CSP 2 2023

    1. half of the glaciers
    2. a third of the glaciers
    3. a fourth of the glaciers
    4. all of the glaciers
    Show answer

    Answer: A. half of the glaciers

    According to a UNESCO report published in November 2022, under a high-emission scenario, half of the glaciers located in UNESCO World Heritage sites could disappear by 2050. Even under a low-emission scenario, one-third of these glaciers would still disappear by 2050.

Extreme Weather Events and Climate Variability

39. Identify the incorrect statement extra- tropical cyclones:

    Asked in: APPSC Group 1 Prelims 2024

    1. These develop in the mid and high latitudes.
    2. They do not have a clear frontal system.
    3. They affect a large area as compared to the tropical cyclones.
    4. They can originate over the land and sea.
    Show answer

    Answer: B. They do not have a clear frontal system.

    Extra-tropical cyclones, also known as mid-latitude cyclones or temperate cyclones, form in the mid- latitudes (between 30° and 60° latitude). They are associated with the interaction of warm and cold air masses and are driven by temperature gradients.

40. The Global Drought Snapshot, released in December 2023 at the beginning of the 28th Conference of the Parties (COP-28) to the UN Framework Convention on Climate Change (UNFCCC) in Dubai, exposes the devastating consequences of droughts on lives, economies, and various sectors. Based on the data reported by 101 parties to the UNCCD, which of the following statements is/are correct? (i) The report reveals that a staggering 1.84 billion people experienced the effects of drought. Among them, 4.7% faced severe or extreme drought conditions. (ii) Notably South Africa faced the highest number of declarations. (iii) Drought severity prompted emergency declarations in 23 countries. (iv) The US, Canada, India and Sri Lanka are the countries that never declared drought emergencies. Select the correct answer using the codes given below.

    Asked in: APSC CCE Prelims Exam 2023

    1. (i) only
    2. (ii) and (iv) only
    3. (i) and (iii) only
    4. (i), (ii), (iii) and (iv)
    Show answer

    Answer: C. (i) and (iii) only

    The report stated that 1.84 billion people were affected by drought, with 4.7% facing severe or extreme conditions, making statement (i) correct. It also highlighted that 23 countries issued emergency declarations due to drought severity, making statement (iii) correct.

41. Which one of the following is not a resultant of the El Nino effect?

    Asked in: UPSC CDS 1 2022

    1. Distortion of equatorial atmospheric circula‐ tion.
    2. Flow of the South-East Trade Winds towards the Indian Ocean.
    3. Irregularities in the evaporation of sea water.
    4. Reduction in the amount of planktons which reduces the number of fish in the sea.
    Show answer

    Answer: B. Flow of the South-East Trade Winds towards the Indian Ocean.

    El Nino's primary impact is on the Pacific Ocean's oceanographic and atmospheric conditions, specifically the weakening/reversal of trade winds and warming of the eastern Pacific, leading to a distortion of the Walker Circulation.

42. El NINO Phenomenon is associated with :

    Asked in: OPSC CS Prelims 2016

    1. Cloud Bursting
    2. Earthquake
    3. Global Warming
    4. Acid Rain
    Show answer

    Answer: C. Global Warming

    El Niño is a significant climate phenomenon associated with the warming of sea surface temperatures in the Pacific Ocean, leading to global changes in weather patterns. While not identical to Global Warming, it is a major component of the global climate system whose behavior and effects are studied in the context of long-term climate change and contribute significantly to interannual variations in global average temperatures. Among the given options, Global Warming is the most relevant broad association.

43. Which climatic phenomenon is characterized by cooler than normal sea surface temperatures in the central Pacific Ocean?

    Asked in: OPSC CS Prelims 2023

    1. La Nina
    2. El Nino
    3. Monsoon
    4. Tornado
    Show answer

    Answer: A. La Nina

    - La Niña is the cool phase of the El Niño-Southern Oscillation (ENSO) climate pattern. - It is defined by below-average SSTs in the central and eastern tropical Pacific.

44. Which disaster is most likely to be influenced by climate change?

    Asked in: OPSC CS Prelims 2023

    1. Earthquakes
    2. Tsunamis
    3. Tropical cyclones
    4. Volcanic eruptions
    Show answer

    Answer: C. Tropical cyclones

    - Tropical cyclones are fueled by warm sea surface temperatures and atmospheric moisture. - Climate change leads to warmer oceans and increased atmospheric moisture. - Increased intensity, rainfall, and storm surge of tropical cyclones are linked to climate change.

Impacts of Climate Change on Ecosystems and Biodiversity

45. If global temperature rises by 2°C, which of the following effects can be seen on the earth ? (a) Annual flooding (b) Insect born diseases like Malaria (c) Shift of agricultural regions (d) Several species of plants and animals will become extinct

    Asked in: MPSC CS Prelims 2013

    1. (a), (b), (c) and (d)
    2. (a), (b) and (c)
    3. (b), (c) and (d)
    4. only (d)
    Show answer

    Answer: A. (a), (b), (c) and (d)

    - A 2°C global temperature rise has significant and wide-ranging impacts. - Impacts include changes in precipitation patterns, disease distribution, agricultural suitability, and biodiversity. - All the listed effects are consistent with projected climate change consequences at this level of warming.

46. Which of the following is the consequence of climate change related warming of rivers?

    Asked in: TNPSC CS Prelims 2021

    1. changes in water salinity
    2. changes in fish migration patterns
    3. changes in pathogen load
    4. changes in contaminant levels
    Show answer

    Answer: B. changes in fish migration patterns

    Water temperature is a critical environmental cue for many fish species, influencing their spawning, migration, and other life cycle events. As rivers warm due to climate change, these temperature cues are altered, disrupting natural fish migration patterns and potentially impacting fish populations and ecosystems.

47. In the context of effect of global warming, match the following : Effect Country/Region

    Asked in: TSPSC Group 1 Prelims 2023

    1. Bush fires I. Antarctica
    2. Locust swarming II. Arctic
    3. Heat wave III. Africa – Middle East
    4. Permafrost melt IV. Australia – USA Choose the correct answer : A. A-IV; B-III; C-I; D-II B. A-I; B-IV; C-III; D-II C. A-III; B-IV; C-I; D-II D. A-III; B-IV; C-II; D-I
    Show answer

    Answer: A. Bush fires I. Antarctica

    - A. Bush fires: Regions like Australia and parts of the USA (e.g., California) have experienced increasingly severe and frequent bushfires linked to climate change, drought, and heat waves. A-IV is a strong match. - B. Locust swarming: Extreme weather events influenced by climate change, such as heavy rainfall followed by dry periods, can create favourable conditions for locust breeding and swarming. Recent large-scale outbreaks have affected East Africa, the Middle East, and parts of South Asia. B-III is a strong match. - C. Heat wave: While heat waves affect many populated areas, the options suggest specific regions impacted by global warming. Antarctica (I) is experiencing significant warming, leading to ice shelf disintegration and changes in ecosystems. While "heat wave" in the conventional sense might apply more to populated areas, unusually high temperatures (heat waves) in polar regions have significant impacts on ice melt. C-I is plausible in this context. - D. Permafrost melt: Permafrost, ground that remains frozen for two or more years, is found extensively in the Arctic region (II). As global temperatures rise, permafrost is melting, releasing stored carbon and impacting infrastructure and ecosystems. D-II is a very strong match.

48. Which of the following reasons caused catastrophic coral bleaching and mass coral deaths in the Andaman and Nicobar Islands?

    Asked in: UPPCS Prelims 2024

    1. Increased industrial activities in the coastal re‐ gions
    2. Increase of 2°C temperature in the Indian Ocean
    3. Heavy marine pollution
    4. Decrease of temperature by 4°C in the Indian Ocean
    Show answer

    Answer: B. Increase of 2°C temperature in the Indian Ocean

    An increase in sea temperature, even by 1-2°C above the normal average for a prolonged period, can cause corals to expel the symbiotic algae (zooxanthellae) living in their tissues, which provide them with colour and nutrients. This phenomenon is called coral bleaching. If the stress is severe or prolonged, the corals can die. A 2°C increase represents a substantial temperature anomaly capable of causing widespread, catastrophic bleaching events like those observed in various parts of the world, including the Andaman and Nicobar Islands.

49. The scientific view is that the increase in global temperature should not exceed 2°C above pre-industrial level. If the global temperature increases beyond 3°C above the pre-industrial level, what can be its possible impact/impacts on the world? 1. Terrestrial biosphere tends toward a net carbon source. 2. Widespread coral mortality will occur. 3. All the global wetlands will permanently disappear. 4. Cultivation of cereals will not be possible anywhere in the world. Select the correct answer using the code given below.

    Asked in: UPSC IAS 2014

    1. 1 only
    2. 1 and 2 only
    3. 2, 3 and 4 only
    4. 1, 2, 3 and 4
    Show answer

    Answer: B. 1 and 2 only

    The question assesses understanding of the projected impacts of significant global warming based on climate science.

50. According to World Health Organisation's report of 2008, the number of diseases due to climate change is

    Asked in: UPPCS Prelims 2015

    1. 6
    2. 15
    3. 20
    4. 25
    Show answer

    Answer: C. 20

    The 2008 WHO report emphasized that climate change is not just an environmental issue but a significant health threat, increasing vulnerability to a wide range of health problems globally, particularly in vulnerable populations.

Impacts on Agriculture, Food Security, and Water Resources

51. The United Nations has recently warned that 'famine-like conditions have been created by climate change' in which one of the following countries?

    Asked in: UPSC Geoscientist 2022

    1. Madagascar
    2. Mongolia
    3. Papua New Guinea
    4. Venezuela
    Show answer

    Answer: A. Madagascar

    In 2021, the United Nations warned about severe drought conditions in Southern Madagascar, directly linking the resulting food crisis and 'famine- like conditions' to climate change, describing it as potentially the world's first famine caused by the climate crisis.

52. Which human activity is most affected by climate?

    Asked in: JPSC CS Prelims 2014

    1. Fishing
    2. Mining
    3. Manufacturing
    4. Farming
    Show answer

    Answer: D. Farming

    Farming (agriculture) is the human activity most directly and significantly affected by climate. Factors like temperature, precipitation, sunshine, and length of growing seasons are fundamental to crop cultivation and livestock raising. Climate determines what crops can be grown in a region, the timing of planting and harvesting, the risk of frost, drought, floods, and pests, and overall yields.

53. Given below are two statements: Statement-I (Assertion A) : Climate change is leading to increase in social tension in India. Statement- II (Reason R) : The frequency and intensity of the extreme weather events will have serious repercussions on food security. Choose the correct answer from the code given below :

    Asked in: UPPCS Prelims 2017

    1. Both (A) and (R) are true and (R) is the correct reason of (A).
    2. Both (A) and (R) are true but (R) is not the correct reason of (A).
    3. (A) is true but (R) is false.
    4. (A) is false but (R) is true.
    Show answer

    Answer: A. Both (A) and (R) are true and (R) is the correct reason of (A).

    - Statement-I (A): Climate change impacts like extreme weather events (droughts, floods, heatwaves) can lead to resource scarcity (water, food), displacement, migration, and economic disruption, all of which can exacerbate existing social tensions and potentially lead to conflict in vulnerable regions, including parts of India. This statement is true. - Statement-II (R): Extreme weather events directly impact agricultural production, causing crop failures and reducing yields. This leads to decreased food availability and increased prices, significantly affecting food security for large populations. This statement is true. - The connection between the statements: Food insecurity (R) caused by climate change impacts is a major driver of social tension (A). Lack of access to food and resources can fuel social unrest, migration pressures, and conflicts, directly supporting the assertion in Statement-I.

Intergovernmental Panel on Climate Change (IPCC) Assessments and Projections

54. As per the IPCC 4th Assessment Report, the average sea level during the period 1961-2003 increased approximately at the rate of :

    Asked in: HPPSC HPAS Prelims 2014

    1. 1.8 cm per year
    2. 5.9 mm per year
    3. 4.1 mm per year
    4. 1.8 mm per year
    Show answer

    Answer: D. 1.8 mm per year

    The IPCC AR4 (2007) synthesized the scientific understanding of climate change, including observations of sea level rise based on tide gauge data.

55. According to the IPCC's Fourth Assessment Report, the average sea level rose during the 1961-2003 period at approximately this rate:

    Asked in: HPPSC HPAS Prelims 2014

    1. 1.8 cm per year
    2. 5.9 mm per year
    3. 4.1 mm per year
    4. 1.8 mm per year
    Show answer

    Answer: D. 1.8 mm per year

    - This specific rate is a key finding reported in the IPCC AR4. - The rate of sea level rise has accelerated in more recent periods (e.g., 3.1 mm/year from 1993 to 2003 as per AR4, and even higher rates in subsequent reports).

56. What does the Intergovernmental Panel on Climate Change (IPCC) emphasize regarding reductions in greenhouse gas (GHG) emission? 1. Gradual and limited reductions are enough. 2. Deep, rapid and sustained reductions are essential. Select the correct answer from the codes given below:

    Asked in: UPPCS Prelims 2024

    1. Both 1 and 2
    2. Neither 1 nor 2
    3. Only 1
    4. Only 2
    Show answer

    Answer: D. Only 2

    The Intergovernmental Panel on Climate Change (IPCC), in its assessment reports, consistently emphasizes the urgent need for "deep, rapid and sustained" reductions in greenhouse gas emissions across all sectors to limit global warming and avoid the most severe impacts of climate change. Statement 1 contradicts the IPCC's findings that significant and swift action is required.

57. In which year was the ‘Inter-governmental Panel on Climate Change’ was set up ?

    Asked in: UPPSC ACF RFO gs 1 2021

    1. 1972
    2. 1976
    3. 1980
    4. 1988
    Show answer

    Answer: D. 1988

    The IPCC is a leading international body for assessing the science related to climate change.

58. In which year was the ‘Inter-governmental Panel on Climate Change’ was set up ? (a) 1972 (c) 1980 (b) 1976 (d) 1988

    Asked in: UPPSC ACF RFO gs 1 2021

    1. (a) 1972
    2. (b) 1976
    3. (c) 1980
    4. (d) 1988
    Show answer

    Answer: D. (d) 1988

    The IPCC does not conduct its own research but rather assesses the scientific, technical, and socio- economic information relevant to understanding climate change, its potential impacts, and options for adaptation and mitigation.

International Conventions and Agreements on Climate Change (e.g., UNFCCC, Kyoto Protocol, Paris Agreement)

59. Global Campaign '350' was observed as an International Day for Climate Action on :

    Asked in: APPSC Group 1 Prelims 2010

    1. 25th October, 2009
    2. 30th October, 2009
    3. 14th October, 2009
    4. 24th October, 2009
    Show answer

    Answer: A. 25th October, 2009

    The Global Campaign '350' was a worldwide grassroots movement advocating for a reduction in atmospheric carbon dioxide levels to 350 parts per million. This campaign culminated in a series of coordinated actions and events on October 24, 2009, designated as the International Day for Climate Action.

60. The Paris Agreement of the UN Framework Convention on Climate Change is to limit global warming well below (benchmark of pre- industrial level)

    Asked in: APSC CCE Prelims Exam 2020

    1. 1.0 °C
    2. 2.0 °C
    3. 2.5 °C
    4. 3.0 °C
    Show answer

    Answer: B. 2.0 °C

    The central aim of the Paris Agreement is to strengthen the global response to the threat of climate change by keeping a global temperature rise this century well below 2 degrees Celsius above pre-industrial levels and to pursue efforts to limit the temperature increase even further to 1.5 degrees Celsius.

61. The United Nations Framework Convention on Climate Change deals with

    Asked in: BPSC Prelims Exam 60 62rd

    1. reduction in fossil fuel usage
    2. CO₂ emissions mitigation
    3. reduction in Uranium production
    4. greenhouse gases emissions mitigation
    Show answer

    Answer: D. greenhouse gases emissions mitigation

    - The ultimate objective of the UNFCCC is to stabilize greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system. - It provides a framework for international cooperation to combat climate change, including efforts to mitigate (reduce) emissions of greenhouse gases like CO₂, methane, nitrous oxide, etc.

62. The 'Kyoto Protocol' is an international treaty that commits State parties to reduction in

    Asked in: UPSC CDS 1 2019

    1. poverty
    2. greenhouse gases emission
    3. nuclear armaments
    4. agricultural subsidy
    Show answer

    Answer: B. greenhouse gases emission

    - The Kyoto Protocol is an international treaty under the UNFCCC. - It sets binding emission reduction targets for developed countries for greenhouse gases.

63. Which of the following statements about 'Marrakech Partnership' is/are correct?

    Asked in: UPSC CDS 1 2024

    1. 1 and 2 only
    2. 1 and 3 only
    3. 1, 2 and 3
    4. 2 only
    Show answer

    Answer: C. 1, 2 and 3

    It is an intergovernmental partnership for global climate action. It is not only an intergovernmental partnership for global climate action but also a collaboration between governments and other stakeholders like cities, businesses and investors. This partnership is guided by the 2030 Agenda for Sustainable Development. Select the correct answer using the code given below. The Marrakech Partnership for Global Climate Action supports the implementation of the Paris Agreement. It mobilizes climate action by Parties (governments) and non-Party stakeholders including cities, businesses, investors, and civil society. Therefore, it is indeed a collaboration that involves governments (making it partly intergovernmental) but is not limited to them (as stated in point 2). The climate action goals under the Paris Agreement are aligned with and contribute to the broader 2030 Agenda for Sustainable Development, particularly SDG 13 on climate action, so the partnership is guided by this agenda.

64. Which of the following statements about the 'Race to Zero Campaign' is/are correct ? One of the main objectives of the Race to Zero Campaign is to build momentum around the shift to a decarbonized economy.

    Asked in: UPSC CDS 2 2023

    1. 1 only
    2. 2 only
    3. Both 1 and 2
    4. Neither 1 nor 2
    Show answer

    Answer: A. 1 only

    It is related to the theory of Zero-Sum Game. Select the correct answer using the code given below : Statement 1 is correct. The 'Race to Zero' campaign is a global initiative that mobilizes actors outside of national governments – including companies, cities, regions, and investors – to commit to achieving net- zero emissions by 2050 at the latest. Its main objective is precisely to build momentum among these non-state actors towards a decarbonized economy to limit global warming. Statement 2 is incorrect. The Race to Zero Campaign is related to achieving net-zero carbon emissions, not the economic concept of a Zero-Sum Game. Climate action is generally viewed as a collective action problem where collaboration leads to a positive outcome for all involved, rather than a scenario where one party's gain is another's loss.

National Action Plan on Climate Change (NAPCC) and India's Climate Policies

65. How many national missions have been started as part of the National Action Plan on Climate Change ?

    Asked in: APPSC Group 1 Prelims 2016

    1. 7
    2. 8
    3. 9
    4. 10
    Show answer

    Answer: B. 8

    NAPCC aims to promote understanding of climate change, adaptation and mitigation strategies, and energy efficiency.

66. Which one of the following statements about the National Adaptation Fund for Climate Change is not correct?

    Asked in: UPSC CDS 1 2018

    1. The fund is meant to assist national and State level activities to meet the cost of adaptation measures.
    2. This scheme has been taken as a Central Sector Scheme.
    3. The Indian Council of Agricultural Research is the national implementing entity for the fund.
    4. The scheme has been in force since 2015-2016.
    Show answer

    Answer: C. The Indian Council of Agricultural Research is the national implementing entity for the fund.

    The National Adaptation Fund for Climate Change (NAFCC) is a Central Sector Scheme fully funded by the Union Government. It was launched in August 2015 (thus in force since 2015-16) to support adaptation measures to climate change in vulnerable sectors and regions. The fund assists national and State level activities for this purpose. The National Bank for Agriculture and Rural Development (NABARD) acts as the National Implementing Entity (NIE) for the NAFCC, responsible for implementing adaptation projects under the fund. The Indian Council of Agricultural Research (ICAR) is the country's premier body for coordinating, guiding, and managing research and education in agriculture, but it is not the NIE for the NAFCC.

67. Which of the following statements about National Action Plan on Climate Change (NAP‐ CC) with reference to India is/are correct ?

    Asked in: UPSC CDS 2 2023

    1. 1 only
    2. 2 only
    3. Both 1 and 2
    4. Neither 1 nor 2
    Show answer

    Answer: A. 1 only

    It emphasises that maintaining a high growth rate is essential for raising the living standards of the vast majority of the people of India and reducing their vulnerability to the impact of climate change. It was released in 2014. Select the correct answer using the code given below : Statement 1 is correct. India's National Action Plan on Climate Change (NAPCC) emphasizes the importance of sustainable development and maintaining a high rate of economic growth as crucial for poverty eradication and enhancing the adaptive capacity and resilience of the population to the impacts of climate change. This reflects India's perspective that development and climate action are intertwined. Statement 2 is incorrect. The National Action Plan on Climate Change (NAPCC) was formally launched in June 2008, not 2014, by the then Prime Minister of India.

68. India has committed to reduce emission intensity of its GDP from 2005 levels by 33-35 per cent by the year:

    Asked in: UPSC Geoscientist 2020

    1. 2022
    2. 2030
    3. 2032
    4. 2035
    Show answer

    Answer: B. 2030

    India's first Nationally Determined Contribution (NDC) under the Paris Agreement included a commitment to reduce the emission intensity of its GDP by 33-35 per cent from 2005 levels by the year 2030.

69. According to the Climate Change Performance Index (CCPI), 2023, India climbed two spots to rank

    Asked in: UPSC Geoscientist 2023

    1. seventh
    2. eighth
    3. ninth
    4. tenth
    Show answer

    Answer: B. eighth

    - India ranked 8th in the CCPI 2023 report, published by Germanwatch, NewClimate Institute, and Climate Action Network. - This represents an improvement of two ranks compared to India's position (10th) in the CCPI 2022.

70. According to the document on National Action Plan on Climate Change, mean surface air temperature in India at the national level has increased by

    Asked in: GPSC Prelims CSP 2 2017

    1. 0.4 ° C over the past century
    2. 0.4 ° C over the past five decades
    3. 0.8 ° C over the past five decades
    4. 0.8 ° C over the past century
    Show answer

    Answer: A. 0.4 ° C over the past century

    The NAPCC, launched in 2008, documented the observed climate change trends in India based on available data at that time.

Ocean Acidification and its Consequences

71. Consider the following statements. 1. The ocean warming increases the frequency of tropical cyclone winds and rainfall. 2. The productivity of the oceans increases when the carbon emission from the atmosphere are sunk by it. Which of the above statement/s is/are correct?

    Asked in: GPSC Prelims CSP 2 2024

    1. 1 only
    2. 2 only
    3. Both 1 and 2
    4. Neither 1 nor 2
    Show answer

    Answer: A. 1 only

    Warmer oceans fuel more intense storms. Ocean carbon absorption (leading to acidification) and warming negatively impact marine productivity.

72. It is reported that there is an ongoing decrease in the pH value of ocean water because of global warming. It happens due to :

    Asked in: UPSC CAPF 2015

    1. larger uptake of CO₂ by ocean water
    2. lesser uptake of CO₂ by ocean water
    3. larger uptake of atmospheric nitrogen by ocean water
    4. lesser uptake of atmospheric nitrogen by ocean water
    Show answer

    Answer: A. larger uptake of CO₂ by ocean water

    Global warming is largely caused by increased atmospheric concentrations of greenhouse gases, particularly CO₂, resulting from human activities. The ocean acts as a significant sink for atmospheric CO₂, absorbing about a quarter of the anthropogenic emissions. When CO₂ dissolves in seawater, it reacts with water to form carbonic acid (H₂CO₃). Carbonic acid then dissociates, releasing hydrogen ions (H⁺), which lowers the pH of the water, making

73. Ozone Layer it more acidic. Increased CO₂ in the atmosphere due to factors causing global warming leads to increased CO₂ uptake by the ocean, driving this acidification process. 308. What is the primary cause of ocean acidification?

    Asked in: WBCS Main Paper 4 2022

    1. Atmospheric CO$_2$ dissolving in ocean wa‐ ter.
    2. Increases in acid rain.
    3. Increased erosion of acid-containing rocks.
    4. Water draining into the ocean has a higher pH from industrial pollutants.
    Show answer

    Answer: A. Atmospheric CO$_2$ dissolving in ocean wa‐ ter.

    When CO$_2$ from the atmosphere dissolves in seawater, it reacts to form carbonic acid (H$_2$CO$_3$). Carbonic acid then dissociates, releasing hydrogen ions (H+) and bicarbonate ions (HCO$_3^-$). The increase in hydrogen ions lowers the pH of the seawater, making it more acidic.

Vulnerability, Adaptation Strategies, and Climate Resilience

74. Which institution released the Adaptation Gap Report 2022?

    Asked in: GPSC Prelims CSP 2 2023

    1. NITI Aayog
    2. UNEP
    3. WEF
    4. UNFCCC
    Show answer

    Answer: B. UNEP

    The report assesses the global progress on adaptation to climate change, highlighting the gaps between the level of adaptation needed and the actions being taken. It covers topics such as planning, finance, and implementation of adaptation measures across various sectors and regions.