Que: What is El Niño? Discuss its causes and its effects on Indian agriculture.

El Niño is a natural climate phenomenon in the Pacific Ocean, known as the “warm current” of the El Niño Southern Oscillation (ENSO). It involves an abnormal increase in the surface water temperature of the eastern tropical Pacific Ocean, which affects the global weather system. The phenomenon was named “El Niño” (meaning “little child”) by Peruvian fishermen because it usually begins around Christmas. El Niño occurs irregularly at intervals of 2 to 7 years and usually lasts for 9 to 12 months, but sometimes even longer. Its opposite phenomenon is La Niña 1 La Niña (cold phase), in which water temperatures decrease.

• Causes of El Niño :
• The main causes of El Niño are linked to climatic and oceanic processes:

• Weakening of the trade winds: Under normal conditions, Trade winds flow westward and push warm water towards the western Pacific, while cold water rises in the eastern part (upwelling). In El Niño, these winds weaken or reverse direction, causing warm water to flow eastward and reducing upwelling.

• Southern Oscillation: This is an atmospheric process in which the difference in air pressure between the Indian and Pacific Oceans changes. El Niño causes high pressure in the western Pacific and low pressure in the eastern part, which affects global weather.

• Increase in ocean temperatures: If the surface water temperature in the eastern part of the Pacific Ocean increases by more than 0.5°C, it is considered an El Niño. This phenomenon is also linked to global climate change, which can increase its intensity. Due to these reasons, El Niño accelerates extreme weather events such as rains, droughts and floods globally.

• Effects of El Niño on Indian agriculture:
• El Niño in India The impact of El Niño is mainly on the monsoon, which affects the agricultural economy. Indian agriculture is largely dependent on the monsoon and El Niño weakens it. Its main impacts are discussed below:

• Weakening of monsoon: El Niño weakens the Indian monsoon, leading to reduced rainfall. El Niño has contributed to six major droughts in India since 1871, such as those in 2002 and 2009. These droughts are more severe in central and northern India, where rainfall can be reduced by 20-30%.

• Reduced crop production: El Niño reduces the production of summer crops such as rice, sugarcane, cotton and oilseeds. 60% of agriculture in India is rain-fed, so erratic rainfall affects crop growth, leading to food insecurity and rising inflation. For example, in 2015-16 El Niño has led to a significant decline in agricultural production.

• Economic and social impacts: The impact on agriculture leads to a decline in GDP. As agriculture is a major contributor to the Indian economy, it leads to water scarcity, livestock losses and a decline in farmers’ income. Furthermore, it can increase the incidence of diseases like cholera, dengue and malaria.

• ​​Other impacts: El Niño increases heatwaves and erratic weather in India, which further affects agriculture. However, some areas may also experience more rainfall. But overall, its impact is negative.

To mitigate these impacts, the Indian government monitors El Niño through the IMD (India Meteorological Department) and adopts measures like irrigation, insurance and alternative crops.