Cause and Effects of El Nino

   El Niño is a naturally occurring phenomenon that is linked to a periodic warming in sea surface temperatures across the central and east-central Equatorial Pacific. El Niño is Spanish for “the boy child,” which is often used to refer to Jesus Christ, and the phenomenon earned this name because it typically occurs in December around Christmas. El Niño occurs every 2-7 years, and can last anywhere between nine months and two years.

El Niño, an oceanic phenomenon usually occurs with Southern Oscillation, an atmospheric phenomenon. Together they are called El Niño Southern oscillation (ENSO). ENSO is one of the most important climate phenomena on Earth due to its ability to change the global atmospheric circulation, which in turn, influences temperature and precipitation across the globe. El Niño Southern Oscillation (ENSO) is the term used to describe the oscillation between the El Niño phase and the La Niña, or opposite phase.

 The causes for El Niña are:

The two opposite phases, “El Niño” and “La Niña,” require certain changes in both the ocean and the atmosphere because ENSO is a coupled climate phenomenon.  “Neutral” is in the middle of the continuum.

 Neutral phase:

• 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. The thermo cline is deeper in the west than the east.
• This means that under “normal” conditions the western tropical Pacific is 8 to 10°C warmer than the eastern tropical Pacific. This warmer area of ocean is a source for convection and is associated with cloudiness and rainfall.

El Nino:

• The trade winds push warm water on the surface of the ocean from east to west (westerly). This causes the warm water to build up on the western side of the ocean near Asia. Meanwhile, on the eastern side of the ocean, near Central and South America, cold waters are pushed up towards the surface.
• Because of this, there is a difference in temperature across the equatorial pacific, with warm water to the west and cold water to the east. The warm water in the west heats the air, making the warm air rise and leading to drastic weather, including rain and thunderstorms.
• The rising warm air causes a circulation between east and west in the Pacific, with the warm, moist air rising in the west, and cool, dry air descending in the east. All of these natural occurrences lead to a reinforcement of the easterly winds, and cause a self-perpetuating motion in the air in the Pacific.

Impacts: The main impacts of El Niño occur in and around the Tropics.

• Extreme Weather events:
  1. Normal or High rainfall in Eastern/Central Pacific, Drought or scant rainfall in western pacific/Asian region.
• Disasters:
  1. Forest fires in Indonesia leading to wiping out of Equatorial rainforest regions.
  2. Heat-waves in India leading to deaths of people and fauna.
  3. Water sources dry up leading to increased distress migration and climate refugees.
• Economic impacts:
  1. Agriculture dependent countries like India face huge losses due to drought conditions. Crop yields are affected leading to food inflation. To tackle food inflation, tweaks in monetary policies to make it tighter, leading to lesser available money supply.
  2. Fishing in equatorial coastal countries like Ecuador and Peru becomes difficult, as fish in the waters near these countries tend to disappear in the months of December and January.
• Social Impacts:
  1. A WHO Paper said that El Niño 2015-2016 is affecting more than 60 million people.
  2. Rising temperatures and more variable rainfall patterns can often reduce crop yields, compromising food security.
  3. This can lead to social unrest, civil wars, increased inequality between people.
  4. El Niño conditions can cause a wide range of health problems, including disease outbreaks, malnutrition, heat stress, and respiratory diseases.
• Environmental impacts:
  1. Effect on aquatic species and sea birds: fish either migrate to other regions or die during an El Niño because they lack adequate food for growth and survival.

Way Forward:

• The government must expand the farm insurance cover and advice banks and financial institutions to settle crop insurance claims in the drought-hit areas without delay.
• High quality seeds of alternative crops must be distributed among farmers in the drought-affected areas.
• Technologies like drip and sprinkler irrigation, precision agriculture.
• Monetary Control measures to tackle inflationary trends in country.
• Financial support from global organizations for rehabilitation and rebuilding.
• Disaster Response Forces to tackle floods and droughts.
• Developing early warning systems and alerting the people much in advance.
• Global co-operation to tackle the climate change which can further aggravate El- Niño and La- Niña conditions.