Geography
Environment and Ecology
Climate Change: Science, Impacts and India's Response
Climate change for CGPSC: greenhouse effect, GHGs and GWP, IPCC findings, impacts on India and Chhattisgarh, NAPCC, India's NDCs and net zero 2070.
Prerequisites
- Ecosystems — the carbon cycle that human activity is disturbing.
- Climate of India and El Niño and La Niña — natural variability, which must be separated from long-term change.
- Energy Resources — the fossil and renewable sources behind emissions and mitigation.
The Hook: A Hotter Raipur, a Late Monsoon
Connect
Ask any farmer in the Mahanadi plains about the last few years: hotter Mays, a monsoon that arrives late and then dumps a week’s rain in a day, dry spells right when paddy is being transplanted. One bad year is weather. A trend over decades is climate.
At the same time, Chhattisgarh mines a large share of India’s coal and runs big thermal power plants at Korba. So the state is both exposed to climate change and part of the energy system that must change. What is the science, what has the world agreed, and what has India promised?
Why it matters: Prelims asks gases, GWP, IPCC facts, NAPCC missions and NDC numbers. Mains GS-II (Paper IV) asks impacts, mitigation vs adaptation and India’s position, and the Essay paper often has a climate theme.
Weather, Climate and Climate Change
| Term | Meaning |
|---|---|
| Weather (मौसम) | Short-term state of the atmosphere (hours to days) |
| Climate (जलवायु) | Average weather over a long period, conventionally 30 years |
| Climate change (जलवायु परिवर्तन) | Long-term shift in climate. The UNFCCC uses it for change attributed directly or indirectly to human activity, over and above natural variability |
| Global warming | The rise in Earth’s average surface temperature, one part of climate change |
The Greenhouse Effect (ग्रीनहाउस प्रभाव)
- Sunlight (short-wave radiation) passes through the atmosphere and warms the surface.
- The surface emits long-wave (infrared) radiation.
- Greenhouse gases (GHGs) absorb and re-emit part of this infrared radiation, keeping the lower atmosphere warm.
Without the natural greenhouse effect, Earth’s average temperature would be about −18°C instead of about +15°C. The problem is the enhanced greenhouse effect from extra GHGs added by humans.
Main greenhouse gases
| Gas | Main human sources | Note |
|---|---|---|
| Water vapour | (Mostly natural) | Most abundant GHG; acts as a feedback, rising as air warms |
| Carbon dioxide (CO₂) | Burning coal, oil, gas; cement; deforestation | Largest contributor to human-caused warming; GWP = 1 by definition |
| Methane (CH₄) | Paddy fields, livestock (enteric fermentation), landfills, coal mines, gas leaks | Short-lived (about a decade) but far more potent per tonne |
| Nitrous oxide (N₂O) | Nitrogen fertilisers, industry | Long-lived |
| Fluorinated gases (HFCs, PFCs, SF₆, NF₃) | Refrigeration, air conditioning, electrical equipment | Very high GWP |
Kyoto basket: the Kyoto Protocol covered six gases (CO₂, CH₄, N₂O, HFCs, PFCs, SF₆); NF₃ was added for its second commitment period.
Global Warming Potential (GWP)
GWP compares the warming caused by one tonne of a gas over 100 years with one tonne of CO₂. Methane is roughly 28 times and nitrous oxide roughly 265–273 times as potent as CO₂ (the exact value depends on the IPCC report used). Some HFCs and SF₆ run into the thousands. Emissions of different gases are added together as CO₂-equivalent (CO₂e).
Chhattisgarh link: Flooded paddy fields produce methane because organic matter decomposes without oxygen. Practices such as alternate wetting and drying and direct-seeded rice can reduce it, which matters for the “rice bowl of India”.
The Evidence (with dates)
| Indicator | Figure | Source / year |
|---|---|---|
| CO₂ concentration | 423.9 ppm global average in 2024, about 52% above pre-industrial (before 1750) | WMO Greenhouse Gas Bulletin (Oct 2025) |
| Increase 2023 → 2024 | 3.5 ppm, the largest annual rise since modern measurement began in 1957 | WMO (2025) |
| Warming | About 1.1°C in 2011–2020 compared with 1850–1900 | IPCC AR6 (2021–2023) |
| Warmest years | 2024 was the warmest year on record (about 1.55°C above pre-industrial); 2015–2025 were the eleven warmest years on record | WMO |
| Human role | Human influence has warmed the atmosphere, ocean and land: “unequivocal” | IPCC AR6, Working Group I (2021) |
A single year above 1.5°C is not a breach of Paris
The Paris Agreement’s 1.5°C goal refers to long-term average warming (about 20 years), not one year. 2024 being about 1.55°C above pre-industrial does not by itself mean the Paris limit has been crossed, though it shows how close the world is.
The IPCC
- Intergovernmental Panel on Climate Change (IPCC), set up in 1988 by the WMO and UNEP; secretariat in Geneva.
- It does not conduct its own research; it assesses published science.
- Three Working Groups: I (physical science), II (impacts, adaptation, vulnerability), III (mitigation).
- AR6 (the Sixth Assessment Report) was completed with its Synthesis Report in March 2023. The IPCC shared the Nobel Peace Prize in 2007 with Al Gore.
Impacts
Global
- Sea-level rise from thermal expansion and melting glaciers and ice sheets.
- Glacier retreat, including in the Himalaya, which threatens the long-term flow of glacier-fed rivers.
- Ocean warming and acidification: the ocean absorbs CO₂, lowering its pH, which harms corals and shell-forming organisms; marine heatwaves cause coral bleaching.
- More frequent and intense extremes: heatwaves, heavy rainfall, droughts, intense cyclones.
- Biodiversity shifts: species move upslope and polewards; some cannot.
- Tipping points: thresholds beyond which change becomes self-sustaining (loss of Arctic summer sea ice, ice-sheet collapse, permafrost thaw releasing methane, Amazon dieback).
- Feedbacks: melting ice lowers albedo (reflectivity), so the darker surface absorbs more heat (a positive feedback).
India
- Monsoon: more variable, with more extreme heavy-rain days and longer dry spells. See Mechanism of the Monsoon.
- Heatwaves across north and central India.
- Agriculture: rainfed crops (most of Chhattisgarh’s paddy) are vulnerable to delayed onset and dry spells.
- Coasts: sea-level rise and stronger cyclones affect the Sundarbans, Odisha, Gujarat and island territories.
- Himalaya: glacial lake outburst floods (GLOFs) and landslides.
- Health: heat stress and the changing range of vector-borne diseases such as malaria (already significant in Bastar).
Chhattisgarh
| Exposure | Why |
|---|---|
| Rainfed paddy | Most cropped area depends on monsoon rain; erratic rainfall directly hits yields and incomes |
| Heat | The plains (Raipur, Bilaspur, Durg, Janjgir) record very high pre-monsoon temperatures |
| Forest-dependent livelihoods | Heat and fire affect forest produce (mahua, tendu) that tribal households rely on |
| Coal economy | A large coal and thermal-power sector faces the long-run energy transition; a “just transition” is needed for workers in belts such as Korba |
| Forest carbon | Dense forests such as Hasdeo Arand are major carbon stores and elephant habitat, which is why coal mining there is contested |
Responding: Mitigation and Adaptation
| Mitigation (शमन) — reduce the cause | Adaptation (अनुकूलन) — reduce the harm |
|---|---|
| Renewable energy, energy efficiency | Drought-tolerant and short-duration crop varieties |
| Afforestation and protecting forests (carbon sinks) | Water harvesting, micro-irrigation, watershed development |
| Low-methane rice practices, better fertiliser use | Heat action plans, early-warning systems |
| Electric mobility, cleaner industry | Crop insurance, climate-resilient infrastructure |
| Carbon pricing and markets | Protecting mangroves and wetlands as natural buffers |
Carbon sink: anything that absorbs more carbon than it releases (forests, soils, oceans). Carbon sequestration is the long-term storage of carbon in such sinks or underground. Carbon credit: a tradable permit representing one tonne of CO₂e reduced or removed.
India’s Policy Response
National Action Plan on Climate Change (NAPCC), 2008
Released on 30 June 2008, with eight National Missions:
| # | Mission | Note |
|---|---|---|
| 1 | National Solar Mission | Later named after Jawaharlal Nehru (JNNSM) |
| 2 | National Mission for Enhanced Energy Efficiency | PAT (Perform, Achieve and Trade) scheme |
| 3 | National Mission on Sustainable Habitat | Buildings, urban transport, waste |
| 4 | National Water Mission | Water-use efficiency |
| 5 | National Mission for Sustaining the Himalayan Ecosystem | |
| 6 | National Mission for a Green India | Afforestation, forest quality |
| 7 | National Mission for Sustainable Agriculture | Climate-resilient farming |
| 8 | National Mission on Strategic Knowledge for Climate Change | Research, capacity |
The government has since announced additional missions (for example on human health and coastal ecosystems). Counts beyond the original eight differ across sources, so remember the eight original missions for Prelims.
State Action Plans on Climate Change (SAPCCs): each state prepares one in line with the NAPCC. The Chhattisgarh State Action Plan on Climate Change was approved by the Government of India in 2014, and a revised second plan has been under preparation.
India’s Nationally Determined Contributions (NDCs)
| Commitment | 2015 (first NDC) | 2022 (updated, for 2030) | 2026 (new NDC, for 2035) |
|---|---|---|---|
| Emissions intensity of GDP (vs 2005) | Cut by 33–35% by 2030 | Cut by 45% by 2030 | Cut by 47% by 2035 |
| Non-fossil share of installed electricity capacity | 40% by 2030 | 50% by 2030 | 60% by 2035 |
| Additional carbon sink (forest and tree cover) | 2.5–3 billion tonnes CO₂e by 2030 | Same | 3.5–4.0 billion tonnes CO₂e by 2035 |
- Net zero by 2070: announced by India at COP26, Glasgow (2021) as part of the “Panchamrit” pledges.
- The 2035 NDC (for the period 2031–2035) was approved by the Union Cabinet on 26 March 2026 and communicated to the UNFCCC.
- Progress (dated): India reported that the emissions intensity of its GDP fell by about 36% between 2005 and 2020. In July 2025, the Ministry of New and Renewable Energy announced that 50% of installed capacity was non-fossil, meeting the 2030 target about five years early.
Intensity target, not an absolute cap
India’s targets are about emissions intensity (emissions per unit of GDP), not total emissions. India’s position rests on equity and Common But Differentiated Responsibilities and Respective Capabilities (CBDR-RC): per-capita emissions in India are far below the world average, and developed countries emitted most of the historical CO₂.
Other Indian initiatives
| Initiative | Year | Point |
|---|---|---|
| Mission LiFE (Lifestyle for Environment) | 2022 | Mass movement for sustainable consumption; launched at Kevadia, Gujarat |
| Carbon Credit Trading Scheme | 2023 | Domestic carbon market under the Energy Conservation (Amendment) Act, 2022 |
| Green Credit Programme | 2023 | Market-based incentive for voluntary environmental actions (tree planting, water conservation) |
| International Solar Alliance | 2015 | Launched by India and France at COP21, Paris; headquarters in Gurugram |
| Coalition for Disaster Resilient Infrastructure (CDRI) | 2019 | Launched by India at the UN Climate Action Summit |
International agreements (UNFCCC, Kyoto, Paris, the COP series) are covered on the next page: Environmental Conventions.
Memory Tricks
India's NDC ladder: '45-50 by 30, 47-60 by 35, zero by 70'
2030: 45% intensity cut, 50% non-fossil. 2035: 47% intensity cut, 60% non-fossil. 2070: net zero. The sink grows from 2.5–3 to 3.5–4 billion tonnes.
NAPCC's eight missions: 'Sun, Saving, City, Water, Mountain, Green, Farm, Knowledge'
Solar, Energy Efficiency, Sustainable Habitat, Water, Himalayan Ecosystem, Green India, Sustainable Agriculture, Strategic Knowledge.
IPCC: '88, WMO + UNEP, Geneva'
Born in 1988 to two parents (WMO and UNEP), lives in Geneva, and only reviews; it never does its own experiments.
Don’t Confuse
| This | vs | That |
|---|---|---|
| Greenhouse effect — natural, keeps Earth habitable | vs | Enhanced greenhouse effect — extra warming from human GHGs |
| Climate change — CO₂ and other GHGs, warming | vs | Ozone depletion — CFCs destroying stratospheric ozone (Montreal Protocol) |
| Mitigation — reduce emissions or increase sinks | vs | Adaptation — adjust to reduce harm |
| Emissions intensity (per unit GDP) | vs | Absolute emissions (total tonnes) |
| IPCC (1988) — scientific assessment | vs | UNFCCC (1992) — the treaty and negotiating forum |
| Global stocktake — collective progress review under Paris | vs | NDC — each country’s own pledge |
Common Mistakes
MCQ traps
- “India has pledged to cut its total emissions 45% by 2030.” Wrong. It is a cut in emissions intensity of GDP, relative to 2005.
- “The 50% non-fossil target refers to electricity generation.” It refers to installed capacity, not the share of electricity actually generated.
- “India’s net-zero year is 2050.” It is 2070.
- “The IPCC was set up by the UNFCCC.” No. It was set up by WMO and UNEP in 1988, before the UNFCCC (1992).
- “Methane is less harmful than CO₂ because it is short-lived.” Per tonne, methane traps far more heat; it is a powerful near-term lever.
- “The ozone hole causes global warming.” They are separate problems with different gases and treaties, although CFCs and HFCs are also greenhouse gases.
Practice
All questions below are original practice questions written in CGPSC style. They are not previous-year questions.
Level 1: Foundation
- Without the natural greenhouse effect, Earth’s average surface temperature would be about ______.
- In which year did India announce its target of net-zero emissions by 2070, and at which COP?
- Name any four of the eight original missions under the NAPCC.
Answers
- About −18°C (instead of about +15°C).
- 2021, at COP26 in Glasgow.
- Any four of: Solar; Enhanced Energy Efficiency; Sustainable Habitat; Water; Sustaining the Himalayan Ecosystem; Green India; Sustainable Agriculture; Strategic Knowledge for Climate Change.
Level 2: Prelims MCQs
Q1. Consider the following statements about India’s Nationally Determined Contribution approved by the Union Cabinet in March 2026:
- It commits India to reduce the emissions intensity of its GDP by 47% by 2035 from the 2005 level.
- It targets 60% of cumulative installed electric power capacity from non-fossil sources by 2035.
- It commits India to an absolute cap on total greenhouse gas emissions from 2030.
Which of the statements given above is/are correct?
- (a) 1 only
- (b) 1 and 2 only
- (c) 2 and 3 only
- (d) 1, 2 and 3
Answer and explanation
(b) 1 and 2 only. The 2035 NDC raises the intensity target to 47% and the non-fossil capacity target to 60%, along with a 3.5–4.0 billion tonne additional carbon sink. India has not adopted an absolute emissions cap; its long-term goal is net zero by 2070.
Q2. Match List I (Greenhouse gas) with List II (Major human source):
| List I | List II |
|---|---|
| A. Methane | 1. Refrigeration and air conditioning |
| B. Nitrous oxide | 2. Flooded paddy fields and livestock |
| C. Hydrofluorocarbons | 3. Burning of coal and deforestation |
| D. Carbon dioxide | 4. Nitrogenous fertilisers |
- (a) A-2, B-4, C-1, D-3
- (b) A-4, B-2, C-1, D-3
- (c) A-2, B-1, C-4, D-3
- (d) A-3, B-4, C-1, D-2
Answer and explanation
(a) A-2, B-4, C-1, D-3. Methane comes from anaerobic decomposition in flooded paddy and from cattle; nitrous oxide from nitrogen fertilisers; HFCs from cooling equipment (they replaced ozone-depleting CFCs); CO₂ mainly from fossil fuels and deforestation.
Q3. With reference to the Intergovernmental Panel on Climate Change (IPCC), which one of the following statements is correct?
- (a) It was established under the Kyoto Protocol.
- (b) It was established by the WMO and UNEP in 1988.
- (c) It conducts its own field measurements of greenhouse gases.
- (d) Its headquarters is in Bonn.
Answer and explanation
(b). The IPCC was set up in 1988 by the World Meteorological Organization and the UN Environment Programme. It assesses published research rather than conducting its own. Its secretariat is in Geneva; Bonn hosts the UNFCCC secretariat, which is a common source of confusion.
Q4. Which one of the following is an example of a positive feedback that accelerates global warming?
- (a) Sulphate aerosols from industry reflecting sunlight
- (b) Melting of Arctic sea ice reducing surface albedo
- (c) Volcanic aerosols in the stratosphere
- (d) Increased plant growth absorbing more CO₂
Answer and explanation
(b). Ice reflects most sunlight; open ocean absorbs most of it. As ice melts, the surface absorbs more heat, which melts more ice. Aerosols (a) and volcanic particles (c) reflect sunlight and cool the surface, and extra plant growth (d) removes CO₂, so none of them accelerates warming.
Level 3: Mains Answer Writing
Q1. (60 words) Distinguish between climate change mitigation and adaptation with one example each from Chhattisgarh.
Model answer outline
- Mitigation: reduces the cause of climate change by cutting emissions or enlarging sinks. Example: solar pumps for irrigation, protecting dense forests such as Hasdeo Arand as carbon stores.
- Adaptation: reduces vulnerability to impacts that are already happening. Example: short-duration, drought-tolerant paddy varieties and farm ponds for dry spells.
- Conclusion: Chhattisgarh needs both, because it is a coal-based energy state with rainfed agriculture.
Q2. (150–200 words) “Chhattisgarh is both a victim of climate change and central to India’s energy transition.” Discuss.
Model answer outline
- Intro: Global CO₂ reached 423.9 ppm in 2024 (WMO). India’s NDCs aim for a 47% cut in emissions intensity and 60% non-fossil capacity by 2035, and net zero by 2070.
- Victim:
- Rainfed paddy exposed to delayed monsoon onset and dry spells.
- Heatwaves in the central plains; health impacts.
- Forest-dependent tribal livelihoods affected by heat and fire.
- Central to the transition:
- A major coal-producing and thermal-power state (Korba, Raigarh); coal underpins national energy security today.
- Large forest cover that can count towards India’s carbon-sink target.
- Potential for solar power, biomass from crop residue and green jobs.
- Tensions: coal mining in dense forests (Hasdeo Arand) vs forest carbon and elephant habitat; revenue and jobs vs long-term transition.
- Way forward: a just-transition plan for coal districts (reskilling, using district mineral funds); climate-resilient agriculture; implementing the revised State Action Plan on Climate Change; community forest rights to protect sinks.
- Conclusion: How Chhattisgarh manages this balance will shape both its own prosperity and India’s climate credibility.
Quick Revision Table
| Fact | Detail |
|---|---|
| Natural greenhouse effect | Earth about +15°C instead of −18°C |
| CO₂ (2024) | 423.9 ppm, about 52% above pre-industrial (WMO, 2025) |
| Warmest year | 2024 (about 1.55°C above pre-industrial); 2015–2025 the eleven warmest |
| GWP (100 years) | CO₂ 1; CH₄ about 28; N₂O about 265–273 |
| Kyoto basket | CO₂, CH₄, N₂O, HFCs, PFCs, SF₆ (+ NF₃ later) |
| IPCC | 1988, WMO + UNEP, Geneva; AR6 synthesis March 2023; Nobel Peace Prize 2007 |
| NAPCC | 30 June 2008; 8 original missions |
| Chhattisgarh SAPCC | Approved 2014; revision under way |
| NDC 2015 | 33–35% intensity, 40% non-fossil, 2.5–3 Gt sink (by 2030) |
| NDC 2022 update | 45% intensity, 50% non-fossil (by 2030) |
| NDC 2035 | Cabinet approval 26 March 2026: 47%, 60%, 3.5–4.0 Gt |
| Net zero | 2070 (announced COP26, 2021) |
| 50% non-fossil capacity reached | Announced July 2025 |
| Mission LiFE | 2022 |
Key Takeaways
Key Takeaways
- The natural greenhouse effect sustains life; the enhanced effect from human GHGs drives climate change.
- CO₂ is the main driver; methane (paddy, livestock) and nitrous oxide (fertiliser) matter for agrarian states like Chhattisgarh.
- The IPCC (1988) assesses the science; AR6 found human influence unequivocal.
- India’s targets are on emissions intensity and non-fossil capacity, with net zero by 2070 and a 2035 NDC (47%, 60%) approved in March 2026.
- Chhattisgarh is exposed (rainfed paddy, heat, forest livelihoods) and pivotal (coal, forests): a just transition is the Mains theme.
What’s Next
- Environmental Conventions — UNFCCC, Kyoto, Paris and the COP series
- Biodiversity — climate change as a driver of biodiversity loss
- Minerals, Energy and Industry of Chhattisgarh — the coal and power sector behind the transition debate
- Agriculture of India — how cropping patterns respond to a changing monsoon
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