As per the prediction of most forecast models, the climate system’s biggest player – El Niño – will return for the first time in nearly four years.
How El Niño affects the planet?
Wet and dry areas: Warm water affects air currents that leave areas wetter or drier than usual.
Storms: It can ramp up storms in some areas, like the southern U.S. while tending to tamp down Atlantic hurricane activity.
Impact on marine life: El Niño can also wreak havoc on the many marine ecosystems that support the world’s fishing industries, including coral reefs and seagrass meadows.
Extreme ocean warming: Specifically, El Niño tends to trigger intense and widespread periods of extreme ocean warming known as marine heat waves.
Global ocean temperatures are already at record highs, so El Niño-induced marine heat waves could push many sensitive fisheries to a breaking point.
In the Bay of Bengal east of India, interactions between El Niño and a tropical airflow pattern known as theWalker Circulation elevate the risk for marine heat waves.
How would it impact India?
Affected monsoon: India’s agricultural production depends on the southwest monsoon, which accounts for 75% to 90% of the total annual rainfall from June to September. El Niño-Southern Oscillation (ENSO) significantly affects the southwest monsoon.
Drought: The monsoon-disrupting weather pattern causes climate chaos across the globe and, often, drought in India.
Between 2001 and 2020, India saw seven El Nino years. Of these, four resulted in droughts (2003, 2005, 2009-10, 2015-16). These years also saw kharif or summer-sown farm output decline by 16%, 8%, 10% and 3%, stoking inflation. Kharif harvests account for nearly half of the country’s annual food supply.
Back to Basics
El Niño is one side of the climatic coin called the El Niño-Southern Oscillation (ENSO). It’s the heads to La Niña’s tails.
It is classified as a periodic fluctuation in sea surface temperature (SST) across the central and eastern tropical Pacific oceans.
It is triggered by a warming of the eastern equatorial Pacific Ocean
El Niño occurs every 2-7 years and can last anywhere between nine months and two years.
El Niño is the warm phase of the El Niño Southern Oscillation (commonly called ENSO) and is associated with a band of warm ocean water that develops in the central and east-central equatorial Pacific (between approximately the International Date Line and 120°W), including off the Pacific coast of South America.
La Nina is the opposite of El Nino and is characterised by cooler currents in the equatorial eastern Pacific.
El Nino Southern Oscillation (ENSO):
The combined phases of La Nina and El Nino are termed El Nino-Southern Oscillation (ENSO).
The phenomenon affects rainfall patterns, global atmospheric circulation, and atmospheric pressure across the planet.
In the neutral state, (neither El Niño nor La Niña) trade winds blow east to west across the surface of the tropical Pacific Ocean, bringing warm moist air and warmer surface waters towards the western Pacific and keeping the central Pacific Ocean relatively cool.