El Nino 2014 and its Probable Impact

This year monsoon has reached the Kerala coast a few days later than the schedule.  This is not very unusual and may not impact the agriculture in general. But what is looming the atmosphere is more severe and may cause severe water crisis in south Asia. This is attributed to the formation of a weather Phenomenon called the El Nino, which can cause drought in South Asia, is only expected to have an impact later in the four-month rainy season.

During the first week of the monsoon there was 40% less monsoon across India.  It is also forecasted that progress of monsoon would be slower and may impact the normal agriculture of the country. Usually, the monsoon covers a great part of India by mid-June, and engulfs its entire landmass by mid-July.

 El Niño refers to a giant pool of warm water swelling in the eastern tropical Pacific Ocean, that sets off a chain reaction of weather events around the world, Effect of El Nino is  devastating in some part of the tropic and countries of southern hemisphere but it benefits some regions in the north. US is is to get benefit from it. India is expected to be the first to suffer, with weaker monsoon rains undermining the nation’s fragile food supply, followed by further scorching droughts in Australia and collapsing fisheries off South America.

El Niño is defined by prolonged warming in the Pacific Ocean sea surface temperatures when compared with the average value. The accepted definition is a warming of at least 0.5 °C (0.9 °F) averaged over the east central tropical Pacific Ocean. Typically, this anomaly happens at irregular intervals of two to seven years, and lasts nine months to two years. The average period length is five years. When this warming occurs for only seven to nine months, it is classified as El Niño "conditions"; when it occurs for more than that period, it is classified as El Niño "episodes". Similarly, La Niña conditions and episodes are defined for cooling.

The first signs of an El Niño are:

1.      Rise in surface pressure over the Indian Ocean, Indonesia, and Australia

2.      Fall in air pressure over Tahiti and the rest of the central and eastern Pacific Ocean

3.      Trade winds in the south Pacific weaken or head east

4.      Warm air rises near Peru, causing rain in the northern Peruvian deserts

5.      Warm water spreads from the west Pacific and the Indian Ocean to the east Pacific. It takes the rain with it, causing extensive drought in the western Pacific and rainfall in the normally dry eastern Pacific region.

El Niño's warm rush of nutrient-poor water heated by its eastward passage in the Equatorial Current, replaces the cold, nutrient-rich surface water of the Humboldt Current. When El Niño conditions last for many months, extensive ocean warming and the reduction in easterly trade winds limits upwelling of cold nutrient-rich deep water, and its economic impact to local fishing for an international market can be serious. 

Global sea surface temperature in May 2013 and May 2014. Photograph: NASA

El Niños also typically damp down hurricane activity. But hurricane Andrew, one of the deadliest and costliest in recent history, that adversely affected Florida in 1992, which was an El Niño year.  Another big issue under El Nino is floods in countries of western Pacific. It may bring devastating floods in countries like Peru, Equador and Chile. The 1997-98 El Niño slashed the catch by 80%, as the fish migrated away from the abnormally warm waters. Luis Icochea, a fisheries expert at the National Agrarian University in Lima, warned that the event this year is developing in a similar way.

Another deadly impact of El Nino is on the social and cultural environment that needs to be understood more seriously. It has an ability to spark civil wars and local violence. During the last 50 years between 1950 and 2000, about 20% civil wars occurred in the El Nino cycle, probably due to the loss of crops, jobs and the psychological effects of hotter weather.   Hsiang told the Guardian that, based on historical data, a Pacific warming of 0.8C is associated with a rise in the annual risk of conflict of 15%. It is certainly a developing situation that we should keep track of and it would be excellent to have policy-makers and the public aware of the potential risk.