SYLLABUS
GS-1: Important Geophysical Phenomena.
GS-3: Conservation, Environmental Pollution and Degradation.
Context: As per the latest monthly Climate Bulletin of Copernicus Climate Change Service (C3S), March 2026 emerged as the fourth-warmest March on record globally.
Key Highlights of the Bulletin
• Global Temperature Snapshot:
- March 2026 was the fourth-warmest March on record globally, with an average surface air temperature of 13.94°C, which was 1.48 °C above the estimated pre-industrial level (1850–1900).
- Europe experienced its second-warmest March on record, and much of the continent witnessed drier-than-average conditions.
• Sea Surface Temperatures:
- Global sea surface temperatures (SSTs) were the second-highest ever recorded for March, only slightly below the record levels of March 2024’s El Niño peak of 21.14°C.
- The average SST over extra-polar oceans (60°S–60°N) remained close to 21°C, highlighting sustained ocean heat accumulation.
• Sea Ice Extremes:
- March 2026 also broke the record for lowest average sea ice extent in the Arctic, measuring approximately 5.7% below the 1991–2020 average.
- In the Antarctic region, sea ice extent was 10% below the March average.
• El Niño Outlook:
- These climate indicators point toward an increasing likelihood of El Niño conditions developing in 2026.
Implications
• Global:
- Rising temperatures are likely to increase the frequency and intensity of extreme weather events, including heatwaves, floods, and cyclones.
- Warmer oceans can trigger marine heatwaves, coral bleaching, and disruptions in marine ecosystems, thereby affecting global fisheries and biodiversity.
- The possibility of El Niño may further elevate global temperatures, as such events typically add 0.1–0.2°C to global averages, amplifying climate risks.
- Declining sea ice accelerates warming through feedback mechanisms, contributing to sea-level rise and polar instability.
• India-Specific:
- India may experience weakened or erratic monsoon patterns during El Niño years, affecting agriculture and water security.
- Increased likelihood of heatwaves and drought conditions could impact public health, energy demand, and rural livelihoods.
- Warmer oceans in the Indian Ocean region may intensify cyclonic activity and coastal vulnerabilities.
About El Niño–Southern Oscillation
• ENSO (El Niño–Southern Oscillation) is a periodic climate phenomenon involving changes in sea surface temperatures (SSTs) and atmospheric circulation in the equatorial Pacific Ocean.
• Normal Conditions:
- Trade winds blow from east to west along the equator.
- Warm water accumulates in the western Pacific, while cold, nutrient-rich water upwells near South America.
• El Niño Phase (Warm Phase):
- Trade winds weaken or reverse.
- Warm waters shift eastward toward the central and eastern Pacific.
- Upwelling reduces, disrupting global atmospheric circulation.
- Defined when SSTs rise by at least 0.5°C above normal for sustained periods.
- El Niño typically occurs every 2 to 7 years and lasts for several months, but there is no fixed schedule.
• La Niña Phase (Cool Phase):
- Trade winds strengthen.
- Enhanced upwelling leads to cooler-than-normal SSTs in the eastern Pacific.
- Reinforces normal circulation patterns.