The Intergovernmental Panel on Climate Change (IPCC) has predicted a global sea level rise of about one metre by AD 2100. What would be its impact in India and the other countries in the Indian Ocean region?
Approach ┬╖ directive: тАЬwhat would beтАЭ
What it asks ┬╖ Assess how about a metre of sea-level rise by 2100 would affect India's coasts and the island and delta countries of the Indian Ocean region.
It asks 2 things тАФ answer each
- Assess the impact of about a metre of sea-level rise by 2100 on India: coasts, ecology, economy and people
- Assess the impact on the other countries of the Indian Ocean region: island and delta states
Open with ┬╖ The IPCC's Sixth Assessment puts likely sea-level rise by 2100 at 0.63-1.01 m under very high emissions, and the north Indian Ocean already rose 3.3 mm a year over 1993-2017; around this ocean lie some of the world's most exposed deltas, cities and atolls.
Cover
- Scale: IPCC AR6 likely rise 0.63-1.01 m by 2100 under very high emissions; north Indian Ocean rose 3.3 mm a year in 1993-2017 (MoES).
- India's coast: NCCR, 33.6% of 6,907 km mainland shoreline eroding 1990-2018; West Bengal 60.5%, Puducherry 56.2%, Kerala 46.4%, Tamil Nadu 42.7%.
- India: deltas (Sundarbans, Mahanadi, Godavari, Krishna), Kerala backwaters, Mumbai, Kolkata, Chennai; mangroves, saltwater intrusion, fisheries; ports, roads, power plants; Lakshadweep and Andaman and Nicobar displacement.
- Region: Maldives, about 80% of islands under a metre above sea level (World Bank); a 1.5-2 m rise would flood a fifth of Bangladesh (NCERT); Sri Lanka, Mauritius, Seychelles; migration and maritime disputes.
- Response: MISHTI mangrove restoration over 540 sq km (2023), CRZ rules, early warning, resilient infrastructure, CDRI and help to island states, plus mitigation.
Close with ┬╖ A rising sea respects no maritime boundary; India must adapt at home and lead the Indian Ocean's response, because the atolls and deltas most at risk cannot face it alone.
Add value (verified)
- IPCC AR6 Working Group I, Summary for Policymakers (2021), B.5.3: likely global mean sea-level rise by 2100 is 0.28-0.55 m under SSP1-1.9 and 0.63-1.01 m under the very high emissions scenario SSP5-8.5.IPCC, Climate Change 2021: The Physical Science Basis, Summary for Policymakers, B.5.3 тЖЧтАЬthe likely global mean sea level rise by 2100 is 0.28тАУ0.55 m under the very low GHG emissions scenario (SSP1-1.9); 0.32тАУ0.62 m under the low GHG emissions scenario (SSP1-2.6); 0.44тАУ0.76 m under the intermediate GHG emissions scenario (SSP2-4.5); and 0.63тАУ1.01 m under the very high GHG emissions scenario (SSP5-8.5)тАЭ
- Ministry of Earth Sciences (PIB, 2023, citing its Assessment of Climate Change over the Indian Region): sea level in the North Indian Ocean rose at 3.3 mm a year over 1993-2017.PIB: Ministry of Earth Sciences reply on climate change over the Indian region (Release ID 1945036) тЖЧтАЬSea-level rise in the North Indian Ocean occurred at a rate of 3.3 mm per year in the last two and half decades (1993-2017).тАЭ
- NCCR shoreline assessment 1990-2018 (MoES, PIB 31 March 2022): 33.6% of the 6,907 km mainland coastline analysed is eroding; West Bengal 60.5%, Puducherry 56.2%, Kerala 46.4%, Tamil Nadu 42.7%.PIB: Union Minister Dr Jitendra Singh says about 33.6% of the coastline is under varying degree of erosion (NCCR, state-wise table: coastline km, eroding km, % eroding) тЖЧтАЬKerala 592.96 275.33 46.4 7 East Coast Tamil Nadu 991.47 422.94 42.7 8 Puducherry 41.66 23.42 56.2 9 Andhra Pradesh 1027.58 294.89 28.7 10 Odisha 549.50 140.72 25.6 11 West Bengal 534.35 323.07 60.5 Total 6907.18 2318.31 33.6тАЭ
- World Bank (2024, Maldives Country Climate and Development Report blog): about 80% of the Maldives' islands sit less than one metre above sea level; seas could rise 0.5-0.9 m by 2100.World Bank blog: Thriving in a Warming World, How Maldives can Adapt to Climate Change (2024) тЖЧтАЬThe Maldives is one of the most vulnerable countries to climate change. About 80 percent of its islands sit less than one meter above sea level. The CCDR warns that sea levels could rise by 0.5 to 0.9 meters by 2100тАЭ
- MISHTI (Mangrove Initiative for Shoreline Habitats and Tangible Incomes, 2023): mangrove development over about 540 sq km across 11 states and 2 Union Territories over five years from 2023-24.PIB: MISHTI scheme promotes development of 540 Sq. Kms Mangroves across 11 States and 2 Union Territories (6 April 2023) тЖЧтАЬMangrove Initiative for Shoreline Habitats & Tangible Incomes (MISHTI)) envisage to comprehensively explore the possible area for development of Mangroves covering approximately 540 Sq. Kms. spreading across 11 States and 2 Union Territories during five years commencing FY 2023-24 onwards.тАЭ
Question: UPSC's CS (Main) 2023, GS Paper III тАФ paper тЖЧ. Approach: Minimalist IAS, checked 3 Oct 2026 (how we verify) тАФ UPSC publishes no model answers. ┬╖
Model answer┬╖ 364words ┬╖ Minimalist IAS
The IPCC's Sixth Assessment (2021) puts likely global sea-level rise by 2100 at 0.63-1.01 m under very high emissions, and the north Indian Ocean already rose 3.3 mm a year over 1993-2017 (MoES). Around this ocean lie some of the world's most exposed deltas, cities and atolls.
Impact in India
- Eroding coast: NCCR found 33.6% of the 6,907 km mainland shoreline eroding over 1990-2018, with West Bengal (60.5%), Puducherry (56.2%), Kerala (46.4%) and Tamil Nadu (42.7%) worst hit; a metre of rise would speed this up.
- Deltas and cities: the Sundarbans, Mahanadi, Godavari and Krishna deltas, the Kerala backwaters and Mumbai, Kolkata and Chennai face permanent inundation and deeper storm surges.
- Ecology: mangroves and beaches squeezed against embankments; saltwater intrusion into aquifers and farmland; fish nurseries lost.
- Economy and people: ports, coastal roads, power plants and salt pans at risk; displacement from Lakshadweep and the Andaman and Nicobar Islands; migration pressure on cities.
тЬПя╕П Map to sketch in the exam ┬╖ India's coasts most exposed to sea-level rise
- Shade: West Bengal, Puducherry, Kerala, Tamil Nadu = over 40% of shoreline eroding, 1990-2018 (NCCR)
- Shade: Lakshadweep, Andaman and Nicobar Islands = low-lying island territories
- Legend: coasts to protect first
Draw on India's official outline (Survey of India boundary).
Impact in the other countries of the Indian Ocean region
- Maldives: about 80% of its islands sit less than a metre above the sea (World Bank), so a metre of rise threatens most habitable land and freshwater.
- Bangladesh: a 1.5-2 m rise would flood about a fifth of the country (NCERT), pushing millions towards India's border.
- Sri Lanka, Mauritius, Seychelles: shrinking coasts, damaged reefs and tourism, and water stress.
- Security: climate migration, disputes over fishing grounds and shifting maritime baselines.
The response needed
- Protect with nature: MISHTI (2023) plans mangrove restoration over about 540 sq km across 11 states and two Union Territories; Coastal Regulation Zone rules must hold the line.
- Prepare: early-warning systems, resilient infrastructure and planned retreat where defence is futile.
- Cooperate: the Coalition for Disaster Resilient Infrastructure, help to island states and shared monitoring, alongside mitigation to slow the rise itself.
A rising sea respects no maritime boundary; India must adapt at home and lead the Indian Ocean's response, because the atolls and deltas most at risk cannot face it alone.
Prepared by Minimalist IAS to the answer standard of Shivam Singh (mentor, 7 years) ┬╖ facts checked against official sources (how we verify) ┬╖ updated 3 Oct 2026. UPSC publishes no model answers: compare your structure and coverage with this, then write your own.
