Q. Most of the unusual climatic happenings are explained as an outcome of the El-Nino effect. Do you agree? (10 marks)

Q. Most of the unusual climatic happenings are explained as an outcome of the El-Nino effect. Do you agree? (10 marks)

Model Answer

Q. Most of the unusual climatic happenings are explained as an outcome of the El-Nino effect. Do you agree? (10 marks)

Paper

GS I

Subject

Geography (Physical Geography – Climatology)

Topic

El Niño and its role in global climatic anomalies / Monsoon variability

Syllabus as Per Notification

Salient features of the world’s physical geography

Important geophysical phenomena such as earthquakes, Tsunami, Volcanic activity, cyclone etc., and geographical features and their location – changes in critical geographical features (including water bodies and ice-caps) and in flora and fauna and the effects of such changes

Approach:

Introduction

Briefly define El Niño as the warm phase of ENSO that disrupts global atmospheric circulation and influences climatic anomalies like droughts and floods.

Establish its importance as a key driver of inter-annual climate variability while hinting that its role may be overstated.

Body

First, highlight how El Niño explains unusual climatic events—especially weak monsoons, global extremes, and temperature rise.

Then critically examine limitations by bringing in other drivers such as IOD, climate change, cryospheric factors, and regional influences, showing a multi-causal climate system.

Conclusion

Conclude with a balanced view: El Niño is a major but not exclusive factor behind climatic anomalies.

Emphasise the need for a holistic understanding integrating multiple climate drivers and the growing impact of global warming

Introduction

El Niño, the warm phase of the El Niño–Southern Oscillation (ENSO), is a periodic warming of the equatorial Pacific Ocean that disrupts global atmospheric circulation. By weakening trade winds and altering the Walker circulation, it redistributes heat and moisture across the globe. Consequently, it is widely associated with climatic anomalies such as droughts, floods, and temperature rise, making it a crucial determinant of inter-annual climate variability.

Body

El Niño as a Major Driver of Unusual Climatic Events

· Weakening of the Indian Monsoon

El Niño has a strong inverse relationship with the Indian summer monsoon:

  • The India Meteorological Department (IMD) projects that the

    2026 monsoon rainfall may decline to ~800 mm

    , compared to the long period average (LPA) of ~870 mm.

  • The

    probability of deficient rainfall has increased to 35%

    , much higher than the climatological probability of 16%.

  • Empirical evidence shows that

    6 out of 10 El Niño years are associated with below-normal rainfall in India

    , highlighting its strong teleconnection.

· Agricultural and Economic Implications

  • Nearly

    60% of India’s agriculture is rain-fed

    , making it highly sensitive to monsoon variability.

  • The

    2015–16 super El Niño

    led to rainfall dropping to

    86% of LPA

    , resulting in drought-like conditions, crop losses, and agrarian distress.

  • Such deficits impact

    food security, rural livelihoods, and inflationary trends

    .

· Global Climatic Extremes

El Niño generates widespread anomalies across continents:

  • Heatwaves and rising global temperatures

    due to increased ocean-atmosphere heat transfer.

  • Flooding in western South America

    (Peru, Ecuador).

  • Droughts in Australia, Indonesia, and parts of Africa

    .

  • Shifts in

    cyclone intensity and distribution

    across ocean basins.

· Amplification of Global Warming Trends

  • Recent scientific studies indicate that

    global temperature spikes are partly driven by the interaction between El Niño and anthropogenic warming

    , contributing to Earth’s energy imbalance.

  • El Niño years (e.g., 2023–24) have coincided with

    record-breaking global temperatures

    , reinforcing its role as a climatic amplifier.

Limitations: Why El Niño Alone Cannot Explain Climatic Events

· Influence of Other Ocean–Atmosphere Phenomena

o Role of the Indian Ocean Dipole (IOD)

  • Indian Ocean Dipole

    is another crucial ocean-atmosphere phenomenon influencing the Indian monsoon.

  • A

    • Enhance moisture availability

    • Strengthen monsoon rainfall

    • Offset the adverse effects of El Niño

    positive IOD phase

    , characterized by warmer western Indian Ocean waters, can:

  • Therefore, monsoon outcomes depend on the combined interaction of ENSO and IOD.

o Influence of Eurasian Snow Cover

  • The extent of

    snow cover over Eurasia

    plays a significant role in determining the strength of the monsoon.

  • Below-normal snow cover

    reduces surface albedo and enhances land heating, thereby strengthening the land-sea thermal gradient.

  • This can potentially

    support a stronger monsoon

    , even in the presence of El Niño conditions.

o Role of Other Atmospheric Systems

  • Several short-term atmospheric phenomena influence climate variability, including:

    • Madden-Julian Oscillation (MJO)

      , which governs intra-seasonal rainfall variability.

    • Jet streams and western disturbances

      , which affect regional weather patterns.

  • These systems create

    short-term fluctuations and regional variations

    that cannot be explained solely by El Niño.

· Increasing Dominance of Climate Change

  • Anthropogenic global warming is emerging as a

    • Increased atmospheric moisture has intensified

      cloudbursts and extreme rainfall events

      .

    • Events such as

      urban floods and marine heatwaves

      occur independently of ENSO phases.

    • Nearly

      three-fourths of recent energy imbalance

      is linked to combined effects of warming and ENSO transitions.

    primary driver of extreme weather

    :

  • Climate change is also

    altering ENSO behaviour

    , making events more intense and less predictable.

· Role of Regional and Anthropogenic Factors

  • Local processes such as

    • Urban heat islands exacerbate temperature extremes.

    • Poor drainage systems cause

      urban flooding

      , independent of El Niño.

    • Deforestation disrupts local hydrological cycles.

    urbanisation, deforestation, and land-use change

    significantly shape climatic outcomes:

· Predictive Uncertainty and Variability

  • ENSO predictions are constrained by the

    “spring predictability barrier”

    , limiting accuracy in early forecasts.

  • Not all El Niño events produce uniform impacts; outcomes vary based on

    intensity, timing, and interaction with other climatic drivers

    .

Critical Analysis

  • El Niño should be understood as a

    climate modulator or amplifier rather than a sole determinant

    of unusual climatic events.

  • It significantly explains

    inter-annual variability

    , especially in monsoonal systems, but cannot account for the

    increasing frequency and intensity of extreme events

    .

  • The present climate regime is

    multi-causal

    , shaped by interactions between ENSO, the Indian Ocean system, cryospheric changes, and anthropogenic climate change.

  • Therefore, El Niño acts as a

    trigger within a complex and evolving climate system

    , rather than a universal explanatory factor.

Conclusion

El Niño is undeniably a major contributor to unusual climatic happenings, especially in influencing monsoon variability and global weather anomalies. However, attributing most climatic disturbances solely to it is an oversimplification. A holistic understanding, integrating multiple ocean-atmosphere interactions and the overarching impact of climate change, is essential for accurately explaining contemporary climatic patterns.