La Niña and Its Impact on Global and Indian Climate

The year 2025 began with the warmest January on record, despite the onset of La Niña, a climatic phenomenon known for cooling the central and eastern Pacific Ocean. This paradox raises concerns about climate change’s intensifying effects, altering traditional weather patterns.

What is La Niña?

• La Niña, meaning “Little Girl” in Spanish, is a climate pattern that represents the cold phase of the El Niño-Southern Oscillation (ENSO) cycle.

• It occurs due to the intensification of the Pacific Trade Winds, which push warm surface waters westward, causing an abnormal upwelling of cold water in the central and eastern Pacific Ocean.

How is La Niña Different from El Niño?

Feature	La Niña	El Niño
Ocean Temperature	Colder than normal in the eastern Pacific	Warmer than normal in the eastern Pacific
Trade Winds	Stronger than normal	Weaker than normal
Rainfall in India	Above normal monsoon	Deficient monsoon
Impact on Global Temperature	Generally cooler	Generally warmer

Impact of La Niña on India

1. Monsoon Rainfall:

   • Leads to above-normal rainfall during the Southwest Monsoon (June-September).

   • Boosts agricultural productivity, particularly for crops like paddy, pulses, and oilseeds.

2. Winter Temperatures:

   • Results in colder-than-usual winters, especially in northern and central India.

   • Leads to increased chances of cold waves and fog in the Indo-Gangetic plains.

3. Cyclonic Activity:

   • Increases frequency of cyclones in the Bay of Bengal.

   • Reduces cyclone activity in the Arabian Sea.

4. Drought and Floods:

   • More rain in India, but droughts in South America and weaker monsoons in Australia.

   • Can cause flooding in parts of Southeast Asia.

Global Climate Impact of La Niña

• USA & Canada: Colder and wetter winters in the Pacific Northwest, drier conditions in the Southwest.

• Australia & Indonesia: Heavier rainfall, leading to increased flood risks.

• South America: Severe droughts in Peru, Chile, and Argentina, affecting agriculture and water supply.

• Africa: Drier conditions in East Africa, increasing the risk of food shortages.

Despite La Niña’s cooling effects, January 2025 was the warmest January on record, highlighting global warming’s dominance over natural climate cycles.

Why is La Niña Important for UPSC?

• GS-1 (Geography): Ocean currents, climate patterns, ENSO cycle.

• GS-3 (Environment & Disaster Management): Impact on agriculture, droughts, and floods.

• GS-3 (Climate Change & Global Warming): Interaction between natural climate variations and human-induced global warming.

UPSC Practice Question

With reference to La Niña, consider the following statements:

1. La Niña leads to an increase in trade wind strength, causing cooling of the central and eastern Pacific Ocean.

2. La Niña is associated with below-normal monsoon rainfall in India.

3. La Niña events can cause droughts in South America and floods in Southeast Asia.

4. La Niña typically results in warmer-than-normal global temperatures.

Which of the statements given above is/are correct?

(a) 1 and 3 only

(b) 1 and 2 only

(c) 2, 3, and 4 only

(d) 1, 2, and 4 only

#LaNiña #ElNiño #ENSO #PacificTradeWinds #IndianMonsoon #CyclonePatterns #ClimateChange #UPSCPreparation