Why El Nino is a concern for Indian monsoon rains

India's weather office has forecast normal monsoon rainfall in 2023. However, a 90 per cent likelihood of an El Nino weather pattern developing during the June-September monsoon season raises the possibility of less than normal rain.

In the past, India has experienced below-average rainfall during most El Nino years, sometimes leading to severe drought that destroyed crops and forced authorities to limit the export of some food grains.

What is El Nino? How does it affect India's monsoon?

El Nino is a weather phenomenon that occurs when ocean temperatures in the central and eastern Pacific Ocean rise above normal. The warming causes changes in atmospheric patterns, leading to a weakening of the monsoon circulation over the Indian subcontinent. As a result, the Indian monsoon tends to be weaker and less reliable during El Nino years.

How close is the correlation between El Nino and monsoon rain?

The correlation between El Nino and Indian monsoon rainfall is significant, despite occasional instances when India gets normal or above-normal rain during El Nino years. Over the past seven decades, the El Nino weather pattern occurred 15 times, with India experiencing normal or above-normal rainfall in six instances. However, a contrasting trend has emerged in the last four El Nino years, with India consistently facing drought conditions and rainfall falling below 90 per cent of the long period average.

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El Nino events are categorised according to the magnitude of temperature rise above normal, as weak, medium or strong.

In 2009, a weak El Nino led to a significant reduction in India's rainfall, plummeting to 78.2 per cent of normal, the lowest recorded in 37 years. Conversely, in 1997, a strong El Nino occurred, yet India received 102 per cent of its normal rainfall. Weather models are suggesting 2023 El Nino could be strong.

Why is the monsoon important?

The monsoon is vital for India, providing about 70 per cent of annual rain and impacting key crops such as rice, wheat, sugarcane, soybeans, and peanuts. Agriculture contributes about 19 per cent to India's $3 trillion economy and employs more than half of the 1.4 billion population.

The monsoon's influence extends beyond agriculture, affecting the wider economy. Sufficient rain boosts overall economic growth, helping to control food price inflation, which has recently risen and led to higher lending rates.

Increased agricultural production could also ease export restrictions on sugar, wheat, and rice. Conversely, drought requires importing food and maintaining export restrictions. In 2009, poor rains forced India to import sugar, driving global prices to record highs.

How does the monsoon affect inflation and central bank policy?

Food accounts for nearly half of India's consumer price index, which the central bank closely monitors while deciding on monetary policy. India received normal or above normal rainfall for the four straight years, still prices of cereals, dairy products and pulses have jumped in recent months and forced the Reserve Bank of India to increase lending rates sharply.

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Below normal rainfall could further stoke food inflation.

Why is the monsoon important for Prime Minister Narendra Modi ahead of a 2024 general election?

Modi remains popular nine years since he came to power but opinion polls suggest rising inflation and unemployment threaten to erode his approval rating. Modi's Bharatiya Janata Party lost a key state election last week. Several northern and central states are holding assembly elections ahead of a general election due in mid-2024.

Good rainfall will lift farmers' incomes and help to keep a check on inflation. Drought could add to anti-incumbency sentiment.