Explain the mechanism of El Niño and analyse its likely socio-economic impact on India's monsoon-dependent economy.

El Niño is the warm phase of the El Niño–Southern Oscillation, marked by a sustained rise of at least 0.5°C in central-eastern equatorial Pacific sea-surface temperatures (SST) [1]. WMO projects a near-record ~2.9°C anomaly for August–October 2026, making its monsoon transmission an immediate economic concern [2].

Mechanism of El Niño

• Normal state: strong easterly trade winds pile warm water in the western Pacific, driving cold-water upwelling off South America; the Walker Circulation rises over the Maritime Continent [1].
• Onset: trade winds weaken or reverse, the western warm pool "sloshes" eastward and upwelling is suppressed — a self-reinforcing ocean–atmosphere coupled feedback [1].
• Circulation shift: the ascending limb migrates to the central-eastern Pacific, leaving subsidence over the Indian Ocean–Maritime Continent belt that suppresses monsoon convection [1].

Weak trade winds → warm pool moves east → upwelling ceases
        → Walker cell shifts → subsidence over India → weak monsoon

Fig: El Niño–monsoon transmission chain

Impact on India's monsoon-dependent economy

• Agriculture: WMO's ASO 2026 outlook places the Indian subcontinent in the drier-than-normal zone [2]; IMD's ENSO–Indian Summer Monsoon Rainfall record shows most strong events coinciding with deficient rainfall [3]. Rainfed kharif crops — rice, pulses, oilseeds — are most exposed.
• Water and energy: depleted reservoirs constrain rabi sowing, raise groundwater pumping costs and reduce hydropower generation.
• Prices and fiscal stress: cereal and pulse food inflation, with higher import, procurement and subsidy outgo.
• Social: wage loss and distress migration among small, marginal and landless households in rainfed districts.
• Moderating factor: a likely positive Indian Ocean Dipole can partly offset El Niño's suppressive effect [2].

El Niño is thus a natural oceanic oscillation whose costs in India are transmitted through the monsoon into farm incomes, prices and livelihoods. Strengthening seasonal early warning, expanding PMFBY risk cover [4] and scaling NICRA and ICAR's climate-resilient varieties [5] can convert forecast lead time into preparedness — advancing both food security and climate-adaptation goals under SDG 13.