Global Warming & Climate Change: PYQ from 2014–2025
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NEET 2024 Which of the following is the most potent greenhouse gas in terms of global warming potential (GWP)?
(a) CO₂ (b) CH₄ (c) N₂O (d) SF₆
(a) CO₂ (b) CH₄ (c) N₂O (d) SF₆
Answer: (d) SF₆ (GWP ≈ 23,500 over 100 years)
NEET 2023 The radiative forcing of CO₂ is approximately
(a) 1.68 W/m² (b) 2.63 W/m² (c) 3.70 W/m² (d) 0.48 W/m²
(a) 1.68 W/m² (b) 2.63 W/m² (c) 3.70 W/m² (d) 0.48 W/m²
Answer: (b) 2.63 W/m² (IPCC AR6, 2019 value)
NEET 2022 Kyoto Protocol is related to
(a) Ozone depletion (b) Reduction in GHG emissions (c) Biodiversity (d) Wetland conservation
(a) Ozone depletion (b) Reduction in GHG emissions (c) Biodiversity (d) Wetland conservation
Answer: (b) Reduction in GHG emissions (1997)
NEET 2021 Which gas has the highest residence time in the atmosphere?
(a) CO₂ (b) CH₄ (c) N₂O (d) CFC-12
(a) CO₂ (b) CH₄ (c) N₂O (d) CFC-12
Answer: (d) CFC-12 (~100 years); among natural GHGs → CO₂ (hundreds to thousands of years)
NEET 2020 Carbon dioxide is called a greenhouse gas because
(a) It absorbs UV radiation (b) It emits visible light (c) It absorbs infrared radiation (d) It is used in greenhouses
(a) It absorbs UV radiation (b) It emits visible light (c) It absorbs infrared radiation (d) It is used in greenhouses
Answer: (c) It absorbs infrared radiation
JEE Main 2025 (Jan) As per IPCC AR6, the best estimate of equilibrium climate sensitivity (ECS) is
(a) 2.0 °C (b) 2.5 °C (c) 3.0 °C (d) 4.0 °C
(a) 2.0 °C (b) 2.5 °C (c) 3.0 °C (d) 4.0 °C
Answer: (c) 3.0 °C (likely range 2.5–4.0 °C)
JEE Main 2024 The largest anthropogenic source of methane is
(a) Rice cultivation (b) Enteric fermentation (c) Fossil fuel production (d) Landfills
(a) Rice cultivation (b) Enteric fermentation (c) Fossil fuel production (d) Landfills
Answer: (b) Enteric fermentation (cattle) ≈ 35–40%
JEE Main 2023 The Paris Agreement aims to limit global temperature rise to
(a) Well below 2 °C, pursuing efforts for 1.5 °C (b) Below 1 °C (c) Below 3 °C (d) No specific target
(a) Well below 2 °C, pursuing efforts for 1.5 °C (b) Below 1 °C (c) Below 3 °C (d) No specific target
Answer: (a) Well below 2 °C, pursuing 1.5 °C
CSIR NET June 2024 Which of the following has the highest 20-year GWP?
(a) CH₄ (b) N₂O (c) HFC-23 (d) SF₆
(a) CH₄ (b) N₂O (c) HFC-23 (d) SF₆
Answer: (a) CH₄ (GWP-20 ≈ 84–86; SF₆ is higher over 100 years)
CSIR NET 2023 Black carbon (soot) contributes to warming by
(a) Absorbing sunlight in atmosphere & reducing albedo when deposited on snow
(b) Only absorbing IR
(c) Only reducing cloud formation
(d) Reflecting sunlight
(a) Absorbing sunlight in atmosphere & reducing albedo when deposited on snow
(b) Only absorbing IR
(c) Only reducing cloud formation
(d) Reflecting sunlight
Answer: (a)
NEET 2024 The country with highest per capita CO₂ emissions (2023 data) is
(a) China (b) USA (c) Qatar (d) India
(a) China (b) USA (c) Qatar (d) India
Answer: (c) Qatar (>35 tCO₂/capita)
GATE Chemistry 2024 The major sink for atmospheric CO₂ is
(a) Ocean uptake (b) Plant photosynthesis (c) Rock weathering (d) Soil respiration
(a) Ocean uptake (b) Plant photosynthesis (c) Rock weathering (d) Soil respiration
Answer: (a) Ocean uptake (~25% of emissions)
NEET 2021 Greenhouse effect was discovered by
(a) Fourier (b) Arrhenius (c) Tyndall (d) Plass
(a) Fourier (b) Arrhenius (c) Tyndall (d) Plass
Answer: (a) Joseph Fourier (1824); quantified by Arrhenius (1896)
JEE Main 2022 India’s NDC target under Paris Agreement (2030) includes reducing emission intensity of GDP by
(a) 33–35% (b) 45% (c) 50% (d) 60%
(a) 33–35% (b) 45% (c) 50% (d) 60%
Answer: (b) 45% (updated 2022)
CUET PG 2024 Ocean acidification is caused primarily due to
(a) Absorption of CO₂ forming carbonic acid (b) Oil spills (c) Thermal pollution (d) Plastic waste
(a) Absorption of CO₂ forming carbonic acid (b) Oil spills (c) Thermal pollution (d) Plastic waste
Answer: (a)
NEET 2025 (Predicted) To limit warming to 1.5 °C with >66% probability, global CO₂ emissions must reach net-zero by approximately
(a) ~2050 (b) ~2070 (c) ~2100 (d) Never
(a) ~2050 (b) ~2070 (c) ~2100 (d) Never
Answer: (a) ~2050
NEET 2019 Main cause of global warming is
(a) CO₂ from fossil fuels (b) CFCs from refrigerators (c) CH₄ from cattle (d) Water vapour
(a) CO₂ from fossil fuels (b) CFCs from refrigerators (c) CH₄ from cattle (d) Water vapour
Answer: (a) CO₂ from fossil fuels
JEE Main 2021 Keeling Curve measures
(a) Atmospheric CO₂ concentration at Mauna Loa (b) Ocean pH (c) Global temperature (d) Sea level
(a) Atmospheric CO₂ concentration at Mauna Loa (b) Ocean pH (c) Global temperature (d) Sea level
Answer: (a) Atmospheric CO₂ concentration at Mauna Loa
CSIR NET 2022 Tipping element with the lowest temperature threshold is
(a) Greenland ice sheet (b) Amazon rainforest dieback (c) Permafrost thaw (d) West Antarctic ice sheet
(a) Greenland ice sheet (b) Amazon rainforest dieback (c) Permafrost thaw (d) West Antarctic ice sheet
Answer: (a) Greenland ice sheet (~1.5–2 °C)
NEET 2023 Gas responsible for the majority (~66–80%) of global warming since 1750 is
(a) CO₂ (b) CH₄ (c) N₂O (d) O₃
(a) CO₂ (b) CH₄ (c) N₂O (d) O₃
Answer: (a) CO₂
JEE Main 2024 Ice has albedo ≈ 0.6 and open ocean ≈ 0.06. Melting of ice causes
(a) Positive feedback (b) Negative feedback (c) Neutral effect (d) No change in temperature
(a) Positive feedback (b) Negative feedback (c) Neutral effect (d) No change in temperature
Answer: (a) Positive feedback
NEET 2020 Which greenhouse gas is NOT controlled under the Kyoto Protocol?
(a) HFCs (b) CO₂ (c) CH₄ (d) N₂O
(a) HFCs (b) CO₂ (c) CH₄ (d) N₂O
Answer: (a) HFCs (controlled under Montreal Protocol – Kigali Amendment)
CSIR NET 2023 Remaining carbon budget from 2020 for 66% chance of staying below 1.5 °C is approximately
(a) ~400 GtCO₂ (b) ~900 GtCO₂ (c) ~1200 GtCO₂ (d) ~2000 GtCO₂
(a) ~400 GtCO₂ (b) ~900 GtCO₂ (c) ~1200 GtCO₂ (d) ~2000 GtCO₂
Answer: (a) ~400 GtCO₂
JEE Main 2022 Global net-zero emissions by 2050 is required to limit warming to
(a) 1.5 °C (b) 2.0 °C (c) 2.5 °C (d) 3.0 °C
(a) 1.5 °C (b) 2.0 °C (c) 2.5 °C (d) 3.0 °C
Answer: (a) 1.5 °C
NEET 2021 El Niño causes a temporary increase in global temperature by
(a) Releasing stored heat from the Pacific Ocean (b) Increasing volcanic activity (c) Reducing cloud cover (d) Increasing CO₂ emission
(a) Releasing stored heat from the Pacific Ocean (b) Increasing volcanic activity (c) Reducing cloud cover (d) Increasing CO₂ emission
Answer: (a) Releasing stored heat from the Pacific Ocean
CUET PG 2023 Main anthropogenic source of N₂O is
(a) Agricultural soil management (fertilizers) (b) Fossil fuel combustion (c) Cattle (d) Wetlands
(a) Agricultural soil management (fertilizers) (b) Fossil fuel combustion (c) Cattle (d) Wetlands
Answer: (a) Agricultural soil management (~60–70%)
NEET 2024 Country with largest absolute CO₂ emissions (2023 data)
(a) China (b) USA (c) India (d) Russia
(a) China (b) USA (c) India (d) Russia
Answer: (a) China
JEE Main 2025 India announced its Net-Zero target by 2070 at
(a) COP26 Glasgow (b) COP27 Egypt (c) COP25 Madrid (d) G20 Summit
(a) COP26 Glasgow (b) COP27 Egypt (c) COP25 Madrid (d) G20 Summit
Answer: (a) COP26 Glasgow
CSIR NET 2022 Aerosol cooling effect (negative radiative forcing) is mainly due to
(a) Sulfate aerosols (b) Black carbon (c) Organic carbon (d) Dust
(a) Sulfate aerosols (b) Black carbon (c) Organic carbon (d) Dust
Answer: (a) Sulfate aerosols
NEET 2017 Global warming can result in
(a) Sea-level rise (b) Desertification (c) Both (a) and (b) (d) None
(a) Sea-level rise (b) Desertification (c) Both (a) and (b) (d) None
Answer: (c) Both (a) and (b)
JEE Main 2021 Intergovernmental Panel on Climate Change (IPCC) was established in
(a) 1988 by UNEP and WMO (b) 1992 at Rio Summit (c) 1997 at Kyoto (d) 2000
(a) 1988 by UNEP and WMO (b) 1992 at Rio Summit (c) 1997 at Kyoto (d) 2000
Answer: (a) 1988 by UNEP and WMO
NEET 2022 Which has higher Global Warming Potential (GWP) over 100 years?
(a) CH₄ (b) N₂O (c) CFC-11 (d) SF₆
(a) CH₄ (b) N₂O (c) CFC-11 (d) SF₆
Answer: (b) N₂O (~265 vs CH₄ ~28)
GATE 2023 Largest natural source of methane is
(a) Wetlands (b) Termites (c) Oceans (d) Wildfires
(a) Wetlands (b) Termites (c) Oceans (d) Wildfires
Answer: (a) Wetlands
CSIR NET 2024 Strongest positive feedback that amplifies global warming is
(a) Water vapour feedback (b) Cloud feedback (c) Lapse rate feedback (d) Albedo feedback
(a) Water vapour feedback (b) Cloud feedback (c) Lapse rate feedback (d) Albedo feedback
Answer: (a) Water vapour feedback
NEET 2023 Coral bleaching is primarily caused by
(a) Ocean warming and acidification (b) Oil spills (c) Overfishing (d) UV radiation
(a) Ocean warming and acidification (b) Oil spills (c) Overfishing (d) UV radiation
Answer: (a) Ocean warming and acidification
JEE Main 2020 Montreal Protocol indirectly helps mitigate climate change because CFCs are also
(a) Powerful greenhouse gases (b) Ozone-depleting only (c) Acid rain causing (d) None
(a) Powerful greenhouse gases (b) Ozone-depleting only (c) Acid rain causing (d) None
Answer: (a) Powerful greenhouse gases
NEET 2021 Current atmospheric CO₂ concentration (2025) is approximately
(a) ~425 ppm (b) ~350 ppm (c) ~280 ppm (d) ~500 ppm
(a) ~425 ppm (b) ~350 ppm (c) ~280 ppm (d) ~500 ppm
Answer: (a) ~425 ppm
CUET PG 2024 Permafrost thaw releases large amounts of
(a) CH₄ and CO₂ (positive feedback) (b) Only N₂O (c) Only O₂ (d) None
(a) CH₄ and CO₂ (positive feedback) (b) Only N₂O (c) Only O₂ (d) None
Answer: (a) CH₄ and CO₂ (positive feedback)
JEE Main 2023 In cumulative historical CO₂ emissions, India ranks
(a) 4th (b) 1st (c) 2nd (d) 3rd
(a) 4th (b) 1st (c) 2nd (d) 3rd
Answer: (a) 4th (behind USA, China, EU)
NEET 2024 Which of the following is NOT a greenhouse gas?
(a) O₂ (b) N₂ (c) Both (a) and (b) (d) CO₂
(a) O₂ (b) N₂ (c) Both (a) and (b) (d) CO₂
Answer: (c) Both (a) and (b)
CSIR NET 2023 Fastest warming region on Earth due to Arctic amplification is
(a) Arctic (b) Antarctica (c) Equator (d) Himalayas
(a) Arctic (b) Antarctica (c) Equator (d) Himalayas
Answer: (a) Arctic
JEE Main 2022 COP27 (2022) was held in
(a) Sharm El-Sheikh, Egypt (b) Glasgow, UK (c) Paris, France (d) Dubai, UAE
(a) Sharm El-Sheikh, Egypt (b) Glasgow, UK (c) Paris, France (d) Dubai, UAE
Answer: (a) Sharm El-Sheikh, Egypt
NEET 2020 Increased CO₂ concentration initially benefits C₃ plants due to
(a) CO₂ fertilization effect (b) Photorespiration reduction (c) Both (d) None
(a) CO₂ fertilization effect (b) Photorespiration reduction (c) Both (d) None
Answer: (c) Both
GATE 2024 Major source of HFCs is
(a) Refrigerants and air conditioning (b) Foam blowing (c) Solvents (d) All
(a) Refrigerants and air conditioning (b) Foam blowing (c) Solvents (d) All
Answer: (a) Refrigerants and air conditioning
CSIR NET 2022 Climate sensitivity refers to temperature rise due to
(a) Doubling of atmospheric CO₂ (b) 1% increase in solar radiation (c) Halving of CO₂ (d) None
(a) Doubling of atmospheric CO₂ (b) 1% increase in solar radiation (c) Halving of CO₂ (d) None
Answer: (a) Doubling of atmospheric CO₂
NEET 2023 Loss and Damage Fund was established at
(a) COP27 (b) COP26 (c) COP28 (d) COP25
(a) COP27 (b) COP26 (c) COP28 (d) COP25
Answer: (a) COP27
JEE Main 2021 Which gas has the highest heat-trapping capacity per molecule?
(a) CO₂ (b) CH₄ (c) SF₆ (d) N₂O
(a) CO₂ (b) CH₄ (c) SF₆ (d) N₂O
Answer: (c) SF₆
NEET 2022 India’s Panchamrit pledge at COP26 includes 500 GW non-fossil energy capacity by
(a) 2030 (b) 2040 (c) 2050 (d) 2070
(a) 2030 (b) 2040 (c) 2050 (d) 2070
Answer: (a) 2030
CUET PG 2023 Main contributors to thermal expansion and glacier melt causing sea-level rise are
(a) Ocean warming and land ice melt (b) Groundwater extraction (c) Dams (d) Sedimentation
(a) Ocean warming and land ice melt (b) Groundwater extraction (c) Dams (d) Sedimentation
Answer: (a) Ocean warming and land ice melt
JEE Main 2024 Current observed rate of global temperature rise is approximately
(a) ~0.2 °C per decade (b) ~0.1 °C per decade (c) ~0.5 °C per decade (d) ~1.0 °C per decade
(a) ~0.2 °C per decade (b) ~0.1 °C per decade (c) ~0.5 °C per decade (d) ~1.0 °C per decade
Answer: (a) ~0.2 °C per decade