Topic 18: Climate Change Effects — Land & Soil
Climate change impact on agriculture and forests, desertification, deforestation, soil erosion/degradation/conservation, and India's organic farming and Zero Budget Natural Farming (ZBNF) response.
Table of Contents
- 1Climate Change Impact — Agriculture & Forests
- 2Desertification vs Land Degradation vs Drought
- 3Desertification
- 4Deforestation
- 5Soil Erosion — Types & Causes
- 6Soil Degradation & Conservation Measures
- 7Organic Farming
- 8Zero Budget Natural Farming (ZBNF)
- 9Current Affairs (2024–2026)
- 10Prelims PYQs
- 11Mains PYQs
- 12Revision Box
Conceptual Clarity — Why this Topic Matters
UPSC tests land & soil impacts of climate change in three distinct ways:
- Definitional / static: precise UNCCD-style distinctions — desertification vs land degradation vs drought, erosion types (sheet→rill→gully), organic vs natural farming inputs (Jeevamrutha vs Beejamrutha).
- Statement-elimination: pairing schemes with the right claim — ZBNF/BPKP (Palekar), PKVY, MOVCDNER, Soil Health Card, UNCCD COP14 (2019, New Delhi), Bonn Challenge 26 mha target.
- Applied / current: India's Land Degradation Atlas figures, FSI forest-cover critique, natural-farming budget scale-up (see Current Affairs section).
Focus especially on the desertification/degradation/drought trio, the erosion progression, and ZBNF-BPKP — the three highest-frequency themes.
1. Climate Change Impact — Agriculture & Forests
- Rising temperatures cause heat stress on crops, altered flowering/grain-fill windows.
- Erratic monsoon: delayed onset, prolonged dry spells, intense rainfall bursts.
- Increased frequency of droughts and floods; rising pest/disease pressure as warmer winters fail to suppress pest populations.
- Forests: increased wildfire frequency/intensity, tree ranges shifting poleward/upslope, greater pest-outbreak vulnerability (e.g. bark beetle).
| Stressor | Mechanism / Impact | India-specific example |
|---|---|---|
| Heat stress | Shortened grain-fill window, spikelet sterility, reduced yields | Wheat yield loss in 2022 heatwave (early March), IMD flagged terminal heat |
| Erratic monsoon | Delayed onset, dry spells + intense bursts disrupt sowing/harvest | 2023 uneven monsoon; ~50% net sown area rain-fed & exposed |
| Pest/disease surge | Warmer winters fail to kill overwintering pests | Fall armyworm spread in maize; locust incursions 2019–20 |
| Forest wildfires | Longer dry seasons raise fire frequency/intensity | Uttarakhand & Himachal forest fires (recurrent summer) |
| Range shifts | Species migrate poleward/upslope, altering forest composition | Apple belt shifting to higher altitudes in Himachal/J&K |
2. Conceptual Clarity — Desertification vs Land Degradation vs Drought
Don't confuse these three
- Land degradation: broadest term — any productivity loss from any cause (erosion, salinisation, waterlogging, pollution) in any climate zone.
- Desertification: sub-type occurring in arid, semi-arid, dry sub-humid areas (UNCCD definition) — not literal desert expansion, but loss of dryland biological productivity.
- Drought: temporary rainfall-deficiency phenomenon that can trigger/accelerate degradation but isn't the same — droughts end, degradation can persist.
The Four Types of Drought (Prelims Favourite)
Drought progresses through stages — UPSC tests the sequence and the defining trigger of each:
| Type | Defined by | Notes |
|---|---|---|
| Meteorological | Rainfall deficiency (>25% below normal over an area) | The first to appear; IMD declares based on rainfall departure |
| Agricultural | Soil-moisture deficit harming crops | Depends on crop stage & soil type, not rainfall alone |
| Hydrological | Deficit in surface/ground water (rivers, reservoirs, aquifers) | Lags rainfall deficit; affects irrigation, power, drinking water |
| Socio-economic / Ecological | Demand for water/food exceeds supply; ecosystem stress | The final, human-impact stage |
3. Desertification
- Per India's Desertification and Land Degradation Atlas (ISRO/SAC): ~30% of India's geographic area under land degradation.
- Worst-affected: Rajasthan, Gujarat, Delhi, Jharkhand, Goa.
- Key drivers: water erosion, wind erosion (Thar fringe), vegetation degradation, soil salinisation from poor irrigation.
- India signatory to UNCCD (1994); hosted COP14 (2019, New Delhi).
- Committed to restoring 26 million ha degraded land by 2030 (Bonn Challenge); announced "Delhi Declaration" on gender-responsive land restoration.
Land Degradation Neutrality (LDN) — the Target Framework
- LDN = a state where the amount & quality of land resources needed to support ecosystem functions remains stable or increases within a given period — losses offset by equal gains ("no net loss").
- Anchored in SDG Target 15.3 ("by 2030, combat desertification, restore degraded land and strive to achieve a land-degradation-neutral world").
- Operates on the hierarchy: Avoid → Reduce → Reverse degradation (avoidance is cheapest/most effective).
- India adopted voluntary LDN targets under UNCCD; the 26 mha restoration pledge feeds this goal.
4. Deforestation
- Deforestation: permanent forest removal for non-forest use (agriculture, mining, infra, urbanisation).
- Reduces carbon sequestration, disrupts local/regional rainfall (forests recycle moisture via evapotranspiration), accelerates soil erosion, drives biodiversity loss/fragmentation (Topic 12).
- Global drivers: agricultural expansion (cattle ranching, palm oil, soy), logging, infra/mining.
- India: legal diversion under Forest (Conservation) Act 1980 is primary formal channel, offset via CAMPA-funded compensatory afforestation (Topic 14).
5. Soil Erosion — Types & Causes
| Type | Mechanism |
|---|---|
| Sheet erosion | Uniform removal of a thin surface soil layer by rainfall/runoff, often unnoticed until significant topsoil is lost |
| Rill erosion | Runoff concentrates into small, well-defined channels (rills), progressively deepening |
| Gully erosion | Advanced rill erosion cutting deep channels (gullies) — seen extensively in the Chambal ravines |
| Wind erosion | Loose, dry topsoil lifted and transported by wind — dominant in Thar desert-fringe areas |
| Coastal/riverbank erosion | Wave/current action removing land along coastlines and riverbanks (Sundarbans, Brahmaputra banks) |
6. Soil Degradation & Conservation Measures
- Salinisation: salt accumulation from poor drainage/over-irrigation, common in canal-irrigated Punjab/Haryana.
- Waterlogging, nutrient depletion (mono-cropping + excess chemical fertiliser without replenishment), soil compaction from heavy machinery.
Conservation measures
- Contour ploughing & terracing: Farming along the natural contour of slopes to slow runoff, widely used in hilly regions.
- Strip cropping & cover cropping: Alternating crop strips and off-season cover crops to reduce exposed bare soil.
- Shelterbelts/windbreaks: Rows of trees planted to reduce wind velocity and wind erosion (used extensively along the Indira Gandhi Canal command area in Rajasthan).
- Agroforestry & watershed management: Integrated tree-crop systems and integrated watershed development programmes (IWMP) to reduce runoff and improve infiltration.
7. Organic Farming
- Organic farming excludes synthetic fertilisers/pesticides/GM inputs; relies on crop rotation, compost, biofertilisers, biological pest control.
- India's flagship programmes: PKVY (cluster-based organic farming), MOVCDNER (North-East value chain).
- Sikkim: India's (and among world's) first fully organic state, 2016.
8. Zero Budget Natural Farming (ZBNF)
- Zero Budget Natural Farming, pioneered by Subhash Palekar, promoted under rebranded Bharatiya Prakritik Krishi Paddhati (BPKP) scheme.
- Aims to eliminate external input costs via on-farm resources: Jeevamrutha (fermented cow dung/urine/jaggery/pulse-flour microbial culture), Beejamrutha (seed treatment), mulching, intercropping.
- Claimed to improve soil health, reduce farmer input-cost debt burden. Andhra Pradesh: leading adopter at scale.
9. Current Affairs (2024–2026)
Union Cabinet approved the NMNF in Nov 2024 as a standalone centrally-sponsored scheme (~₹2,481 crore outlay), targeting 1 crore farmers and 7.5 lakh hectares under chemical-free natural farming — a scaled successor to BPKP.
India continues progress-tracking toward its COP14 (2019, New Delhi) commitment to restore 26 million ha of degraded land by 2030 (Bonn Challenge), with periodic ISRO Land Degradation & Desertification Atlas updates; latest Atlas shows ~30% of area degradation-affected.
PM-PRANAM scheme incentivises states to cut chemical-fertiliser use; Soil Health Card cycle continues to guide balanced nutrient application and curb over-application-driven degradation.
10. Prelims PYQs
Q. With reference to "Zero Budget Natural Farming," consider the following statements:
1. It promotes the use of "Jeevamrutha," a fermented microbial culture prepared from cow dung and urine.
2. It relies heavily on chemical fertilisers to boost yield in early years.
3. It was pioneered by Subhash Palekar.
Which of the statements given above is/are correct?
Ans: (b). ZBNF uses Jeevamrutha and was pioneered by Palekar; it explicitly avoids chemical fertilisers, so statement 2 is wrong.
Q. "Climate Action Tracker" and "Renewable Energy Country Attractiveness Index" are related to which one of the following?
Ans: (b). Both are independent global rating/tracking tools for climate and clean-energy performance, not treaty bodies or finance mechanisms.
Q. Desertification is best defined as:
Ans: (b). This is the exact UNCCD definition — note it is confined to arid/semi-arid/dry sub-humid zones, not literal desert expansion.
Q. "Sikkim" is often cited in the Indian sustainable-agriculture context because:
Ans: (a). Sikkim became India's first fully organic state in 2016. UNCCD COP14 was hosted in New Delhi, not Sikkim.
Q. Which of the following are the causes of soil salinisation in canal-irrigated areas?
1. Over-irrigation without adequate drainage
2. Rise of the water table bringing dissolved salts to the surface
3. Excessive use of nitrogenous fertilisers alone
Select the correct answer using the code given below:
Ans: (a). Salinisation stems from over-irrigation + water-table rise bringing salts up; nitrogenous fertiliser alone does not cause salinisation.
Q. Consider the following statements regarding shelterbelts:
1. They are rows of trees/shrubs planted to reduce wind velocity and control wind erosion.
2. The Indira Gandhi Canal command area in Rajasthan has used shelterbelts extensively.
Which of the statements given above is/are correct?
Ans: (c). Both are correct — shelterbelts cut wind velocity/erosion and are used extensively along the Indira Gandhi Canal command area.
11. Mains PYQs
Q. How is the growth of the private sector viewed as a supplement to the achievement of India's food security objectives? Also discuss the role of climate-resilient agriculture in this context.
Model Answer Framework
- Introduction: Food security = availability, access, affordability, stability; climate change threatens all four via yield volatility.
- Body — private sector as supplement:
- Investment in cold chains, warehousing, food processing (reduces post-harvest loss)
- Agri-tech, precision farming, seed R&D, market linkages (e-NAM, FPOs)
- Contract farming, climate-resilient input supply
- Body — climate-resilient agriculture:
- Drought/flood/heat-tolerant seed varieties (ICAR-NICRA)
- Micro-irrigation (PMKSY), natural farming (NMNF), Soil Health Card
- Crop diversification, agroforestry, weather-based insurance (PMFBY)
- Conclusion: Public-private synergy — state ensures equity/safety nets, private drives efficiency/innovation — makes food security climate-proof.
Q. What is water-use efficiency? Describe the role of micro-irrigation in increasing the water-use efficiency in agriculture and reducing soil degradation.
Model Answer Framework
- Introduction: Define water-use efficiency (WUE) = crop output per unit water consumed; India's flood-irrigation is highly inefficient.
- Body — micro-irrigation and WUE:
- Drip & sprinkler deliver water directly to root zone — cuts evaporation/runoff losses, raises WUE by 40–60%
- Enables fertigation (precise nutrient delivery), supports "per drop more crop" (PMKSY)
- Body — reducing soil degradation:
- Prevents waterlogging & salinisation from over-irrigation
- Reduces water-table rise, avoids surface salt accumulation
- Lower runoff → less soil erosion & nutrient loss
- Conclusion: Micro-irrigation is a dual-win — water security plus soil health; scale-up via subsidy + FPO adoption is key.
Q. Explain the various types of revolutions that took place in agriculture after independence in India. How have these revolutions helped in poverty alleviation and food security, while also raising concerns of soil health?
Model Answer Framework
- Introduction: Post-independence agriculture transformed through colour-coded revolutions targeting specific commodities.
- Body — types:
- Green (foodgrains, Borlaug/Swaminathan), White (milk, Operation Flood/Kurien), Blue (fisheries), Yellow (oilseeds), Golden (fruits/horticulture), Pink (meat/poultry), Silver (eggs)
- Body — gains: self-sufficiency in foodgrains, higher farm incomes, buffer stocks, rural employment, poverty reduction.
- Body — soil-health concerns:
- Green Revolution's chemical-fertiliser/pesticide overuse → nutrient depletion, salinisation (Punjab/Haryana)
- Groundwater over-extraction, monoculture, declining soil organic carbon
- Conclusion: Shift to an "Evergreen Revolution" (Swaminathan) — productivity without ecological harm via natural farming + Soil Health Card.
Q. What are the salient features of the "National Agroforestry Policy" of India? How will it help in restoring ecological balance and combating land degradation?
Model Answer Framework
- Introduction: India was the first country to adopt a National Agroforestry Policy (2014); agroforestry = integrating trees with crops/livestock.
- Body — salient features:
- Dedicated Agroforestry Mission; simplified regulations for tree-felling/transit on private land
- Institutional credit, insurance, quality planting material, market linkages
- Convergence with MGNREGA, NBM, watershed programmes
- Body — ecological/land-degradation role:
- Trees anchor soil, cut wind/water erosion, improve infiltration
- Carbon sequestration, biodiversity corridors, restored degraded/marginal land
- Supplementary farmer income diversifies climate risk
- Conclusion: Agroforestry is a low-cost, high-impact tool aligning land restoration with the Bonn Challenge 26 mha target.
Q. There is a point of view that agriculture in India has come to be trapped in a vicious circle — sustainability is under threat due to soil degradation, water depletion and climate variability. Comment.
Model Answer Framework
- Introduction: Frame the "vicious circle" — intensive agriculture degrades resources, which further lowers productivity, forcing more intensification.
- Body — the three threats:
- Soil degradation — ~30% area affected; salinisation, nutrient depletion, erosion
- Water depletion — falling water tables (Punjab/Haryana), free-power-driven over-extraction
- Climate variability — erratic monsoon, heat stress, ~50% rain-fed exposure
- Body — breaking the circle:
- Micro-irrigation (PMKSY), natural farming (NMNF/ZBNF), crop diversification away from paddy-wheat
- Soil Health Card, agroforestry, watershed development, climate-resilient seeds (NICRA)
- Conclusion: Sustainability needs a resource-regenerating model — the "Evergreen Revolution" — not further input-intensification.
15-Minute Revision Box
Must-Remember Facts — Climate Change Effects on Land & Soil
- Land degradation = broadest (any productivity loss anywhere); desertification = degradation in arid/semi-arid/dry sub-humid zones (UNCCD); drought = temporary rainfall deficiency
- ~30% of India's area degraded (ISRO Atlas); Rajasthan, Gujarat, Delhi, Jharkhand, Goa most affected
- Erosion progression: sheet → rill → gully; others: salinisation, waterlogging, nutrient depletion, compaction
- UNCCD COP14 (2019, New Delhi); India to restore 26 million ha degraded land by 2030 (Bonn Challenge); LDN = SDG 15.3 no-net-loss
- FSI: net forest+tree cover rising, but often plantation/agroforestry masking natural-forest loss
- Organic farming = PKVY, MOVCDNER; Sikkim = first fully organic state (2016)
- ZBNF/BPKP: Subhash Palekar; Jeevamrutha + Beejamrutha; Andhra Pradesh leading; under NMSA/NAPCC