Explained | What is El Nino that could emerge in 2023 leading to severe drought in India 

By Manjori Borkotoky and Dr. Partha Jyoti Das

The phrase ‘El Nino’ means Little Boy or Christ Child in Spanish. According to NOAA, the name came into being when South American fishermen first noticed unusual warm water periods in the Pacific Ocean in the 1600s. The full name used then was ‘El Nino de Navidad’ as El Nino usually peaks around the month of December. 

The National Geographic website says, “El Niño is a climate pattern that describes the unusual warming of surface waters in the eastern tropical Pacific Ocean. El Niño is the “warm phase” of a larger phenomenon called the El Niño-Southern Oscillation (ENSO).”

The ENSO (El Niño and the Southern Oscillation) is an ocean-atmosphere coupled phenomenon characterized by a periodic fluctuation in the sea surface temperature (SST) as well as air pressure across the Equatorial Pacific Ocean. 

ENSO has three phases: (i) El Nino is the warm phase of the ENSO which is said to occur when the water in the central and eastern tropical Pacific Ocean warms up due to higher than normal SST; (ii) La Nina is the cool phase of ENSO which occurs when the water in the central and eastern tropical Pacific Ocean cools down due to lower than normal SST; (iii) Neutral: During the neutral state of the ENSO the waters in the tropical Pacific Ocean maintains nearly average SST.

The ENSO occurs periodically with an interval of 2 to 7 years with the EL Nino and La Nina creating significant rise and fall of ocean temperatures and thereby triggering fluctuations in the atmospheric pressure and thus affecting wind and rainfall patterns across the tropic impacting the weather and climate domains of almost all over the world. In other words, by exerting influence on global climate circulation, the ENSO cycles cast a widespread impact on human societies’ physical, environmental, and socioeconomic aspects. 

Impact on global temperatures

The ENSO’s control over global temperatures is well documented. The historical variation of the global air temperatures clearly indicates that the hotter years correspond to El Ninos and the relatively less hot years are related to La Ninas. So far the year 2016 has been recorded as the hottest in the period 1880-2022 (the last 143 years) when the global average temperature was higher than the long-term average maintained during 1850-1900 by an amount of about 1°C. 

Impact of Climate Change 

According to a study published in Nature, climate change will have a significant impact on El Nino-La Nina weather patterns approximately by 2030 and this will be a decade earlier than previously predicted resulting in further climate disruptions. The study found that ENSO’s scale is significant enough to influence the global climate.

Indian Context 

In India, the year 2016 remains the warmest on record with a mean anomaly of 0.71°C compared to the LPA of the period 1981-2010. This happened due to the strong El Nino that prevailed during 2015-2016. 

Scientific evidence is available in plenty about the correlation of the ENSO events with the Indian summer monsoons. However, the mechanisms through which these atmospheric teleconnections work are complicated and yet to be fully understood. El Ninos, on many occasions, have been found to be associated with low rainfall, droughts, heat waves, and food insecurity in the Indian sub-continent. On the other hand, several La Ninas are known to have caused high rainfall, flooding, and cold extremes in the South Asian region. 

The El Nino years of the past such as 1877, 1887, 1899, 1911, 1914, 1918, 1953, 1972, and 1976 were also years of droughts varying from severe to moderate, resulting from rainfall deficiencies in many parts of India. The large-scale droughts that occurred in India in the years 1987, 2002, and 2004 in recent times are believed to have links to the contemporary El Nino. 

Similarly, some big events of floods that happened in many parts of India, especially in eastern and north-eastern India in 1988, 1998, 2000, 2008, and 2012 are attributed to the La Nina that persisted in those years.    

El Nino 2023-24

It is known well that the planetary weather has remained under the grip of a long-prevailing La Nina which started back in September 2020 and developed further over three successive years to become a triple dip La Lina, as well as one of the longest-surviving La Ninas. Based on observations of the gradual diminishing of the La Nia signals from December 2022 onward, scientists have seen the possibility of this La Nina lingering on till February 2023 after which it will transit to the neutral conditions of the ENSO cycle. 

In the meantime, several reputed scientific organizations have predicted that an El Nino is highly likely to appear following the ENSO neutral phase this year. Since El Nino usually appears in the winter (e.g., December-January-February), it is expected to develop fully in the year 2024. Therefore, its impacts are anticipated to be seen mainly in the year 2024. This is the reason, why scientists have alerted the world about a warmer 2023 and 2024 which may even catapult the global atmospheric temperature to the and beyond 1.5°C mark thus crossing the first danger mark, marked by the Paris Agreement. We may see new records for the hottest year in the next two years.

IMD Director General M Mohapatra said to Hindustan Times, “We should wait for a few months to get a clearer picture. There is no need to worry about it at the moment because we are first transitioning to ENSO-neutral conditions after the winter season.”

El Niño could also worsen India’s inflation worries in 2023 by affecting the country’s agriculture sector. Supplies of farm commodities could be impacted by drought causing an increase in food prices. 

Preparatory measures needed

With more advancement in scientific knowledge about planetary climates and computing technology, scientists are now in a better position to provide reliable early warning about impending climatic events such as EL Nino and La Nina and their possible impact on lives and environs across the globe. Such prior information needs to be used to assess possible risks for vulnerable groups in the susceptible regions. Back in India as well as other south Asian countries, it should be a priority for national and provincial governments to take preparatory measures to deal with crises like water scarcity, droughts, crop failure, heat waves, and consequent socioeconomic, health, and ecological issues that could be unleashed from such global climatic cycles. 

Although the nature of the impact of climate change on the ENSO is not well comprehended, the intensification of both El Nino and La Nina of late has been attributed to anthropogenic global warming and consequent climatic change. Therefore, researchers have alarmed the world with a sense of foreboding that future El Ninos may be more disastrous for many countries of the world.

(Senior Climate and Environmental Scientist, Dr Partha Jyoti Das is the in-house expert of CFC)