Explain the mechanism of El Niño–Southern Oscillation and assess how record Pacific warming in 2026 could affect India's agriculture and food security.

El Niño–Southern Oscillation (ENSO) is a natural ocean–atmosphere cycle in the tropical Pacific that recurs every 2–7 years. In October 2026, the sea surface temperature (SST) of the Niño 3.4 region rose above 30°C for the first time in recorded history [1]. This makes the 2026–27 event a serious test for India's farm planning.

Mechanism of ENSO

• Normal phase: Strong easterly trade winds pile warm water near Indonesia. This drives the Walker circulation, with rising air over the western Pacific and sinking air near Peru.
• El Niño phase: The trade winds weaken. Warm water moves east and the thermocline deepens off South America. Convection also shifts east, so the descending limb of the circulation settles over the Indian region.
• Southern Oscillation: This is the atmospheric half of ENSO: a pressure see-saw between Tahiti and Darwin.

Weak trade winds → warm pool shifts east → Walker cell shifts
→ subsidence over India → suppressed rainfall

Fig: ENSO–India teleconnection

• Measurement: NOAA's Climate Prediction Center (CPC) adopted the RONI (Relative Oceanic Niño Index) in 2026. It removes background tropical warming from the ENSO signal [3]. CPC puts the chance of a historic event (RONI ≥ +2.5°C) at 83% for Oct–Dec 2026 [2].

Likely impact on India

• Timing: The event is expected to peak around December 2026, at about +3.7°C [5], and to last through February 2027 [4]. So the main risk falls on the northeast monsoon and rabi sowing, mainly through lower reservoir and soil-moisture recharge in the south.
• Heat stress: Above-normal temperatures are likely over almost all land areas [4]. This threatens wheat grain-filling in early 2027.
• Food security: Lower output of pulses, oilseeds and vegetables may push up food inflation. Rain-fed smallholders would be hit hardest in income and nutrition.
• Moderating factors: A positive Indian Ocean Dipole is forecast [5]. Local outcomes also depend on other climate drivers [4]. A stronger El Niño therefore does not mean a proportionally worse impact.

Preparedness

• The government has updated District Agriculture Contingency Plans, issued ICAR advisories for short-duration crops and run PMFBY/KCC enrolment drives [6].
• Further priorities: buffer-stock release, micro-irrigation, and heat action plans before summer 2027.

ENSO's eastward shift of Pacific warmth has a well-understood link to Indian rainfall, but the 2026 record warming makes the outcome for India a risk, not a certainty. Using forecast lead time well, through crop diversification, water conservation and targeted food distribution, can turn this risk into managed resilience and protect SDG-2 (Zero Hunger).