A study on coral microatolls in the Maldives shows sea levels in the central Indian Ocean have been rising since the late 1950s.

Key Highlights 

• Sea level rose by ~0.3 m from 1930–2019, confirming long-term acceleration.
• Rates of rise:
  • 1–1.8 mm/yr (1930–59)
  • 2.7–4.1 mm/yr (1960–92)
  • 3.9–4.8 mm/yr (1990–2019)
• Since 1959, the average rise = 3.2 mm/yr, increasing to ~4 mm/yr in recent decades.
• Maldives–Lakshadweep region has seen a 30–40 cm increase over the last 50 years.

Key Findings of the Report

• Acceleration of Sea-Level Rise: Sea-level acceleration began in the 1950s, contrary to the common belief that it started only in the 1990s.
• Scientific Evidence: Coral growth bands and uranium dating techniques provided highly precise and long-term records of sea-level changes.
• Impact: Interruptions in coral growth were linked to El Niño, Indian Ocean Dipole (IOD), and lunar tidal cycles, showing strong connections between sea-level fluctuations and climatic events.
• Unique Regional Dynamics: The central Indian Ocean experienced earlier and faster sea-level rise compared to coastal regions, driven by distinct oceanographic and atmospheric factors.

Causes of Sea-Level Rise

• Thermal Expansion: Ocean heat absorption causes seawater to expand, raising levels.
• Glacial & Ice-Sheet Melting: Melting of Himalayan, Arctic, and Antarctic ice adds freshwater to oceans.
• Indian Ocean Warming: Above-average warming intensifies currents and circulation, driving higher local rise.
• Climate Variability: Phenomena like El Niño, IOD, and wind shifts amplify regional fluctuations.

Implications

• Ecological Consequences: Rising seas threaten coral reefs, mangroves, and coastal ecosystems, undermining biodiversity and natural buffers.
• Social and Human Impact: Coastal communities face displacement, loss of livelihoods, and health risks due to salinity intrusion and flooding.
• Economic Challenges: Ports, fisheries, and tourism industries are at risk, increasing infrastructure costs and disaster recovery burdens.
• Geopolitical Dimensions: Accelerated sea-level rise in the Indian Ocean raises concerns for maritime boundaries, Exclusive Economic Zones (EEZs), and regional security.
  

Way Forward

• Monitoring & Research: Use coral microatolls, tide gauges, and satellites for long-term sea-level records.
• Coastal Resilience: Restore mangroves, build seawalls, and invest in climate-resilient infrastructure.
• Regional Cooperation: Indian Ocean Rim nations must share data and coordinate adaptation strategies.
• Global Climate Action: Meet Paris Agreement targets to curb emissions and limit ocean warming.
• For India (Lakshadweep Focus): Conserve island ecosystems, prepare for disaster management, and invest in adaptation measures.

DOWNLOAD PDF