2014 could be an El Niño year. This weather event has historically caused devastations across countries. Its mysterious nature is keeping scientists and policy makers on their toes. Jyotsna Singh unravels uncertainties surrounding El Niño and its possible impact on Indian monsoon
After a scorching May this year, the month of June, which is marked by the onset of monsoon, proved to be one of the driest for India since record keeping began over a 100 years ago. This was followed by a warning from the newly elected BJP government at the Centre about the possibility of a drought-like situation in western India, and directives to the states to roll out their contingency plans.
The warning could not have come at a worse time. In a year when world economies are struggling to tame food inflation and the US, Australia and parts of Africa are trying to overcome prolonged droughts, the World Meteorological Organization (WMO) has issued a warning to prepare for an inclement weather. “An El Niño episode will continue to develop over the coming weeks and months. This will strongly affect the weather and the pattern of droughts and floods in many parts of the world. Countries must prepare carefully for the likely impacts, including on human safety, agriculture and fisheries,” warns Michel Jarraud, secretary-general of WMO.
The weather fluctuation is not new. It returns at random intervals of two to seven years. The phenomenon begins as an abnormal warming of tropical eastern Pacific Ocean along the coasts of Peru and Ecuador towards April (see infograph). But no one knows why this happens. By December the warm Pacific currents alter the worldwide climate by hindering the flow of trade winds, which encircle the earth along the equator, blowing from high-pressure belts in the east to low-pressure zones in the west. The result is heavy rains and floods in South and North Americas, drought in South Asia and Australia, and mixed extreme weather events in Africa (see `Drought, flood and uncertainties').
In India, El Niño is typically associated with patchy monsoon and drought. India Meteorological Department (IMD) has forecast a below normal rainfall during the summer monsoon. In a country where 60 per cent of farms are rain-fed, weak rains could lower agricultural output, resulting in a spike in inflation. This poses a major challenge for the country's newly elected government of Narendra Modi. Its four key Union ministries—agriculture, food, fertilisers and water resources—and state governments are frantically preparing to deal with any possible failure of monsoon. Contingency plans have been chalked out in 500 districts, where authorities are preparing nurseries for short-duration crops that can withstand low rainfall, issuing location-specific advisories and monitoring the situation closely.
|fish enchovetta's population collapsed, bringing huge losses to the fishing industry|
In the last decade, the country witnessed severe droughts in 2002, 2004 and 2009—all coinciding with El Niño years. In 2009, the worst drought in three decades led to high food inflation, which remains untamed. In fact, it became a major reason for the rout of the upa government.
The governments of other countries bordering the Pacific Ocean are also on their toes. Australia has asked its livestock rearers to take to large-scale culling to cut down fodder and feed demand, and has issued a warning of a global shortage of beef. There is also a flutter in the global agricultural produce market. Cocoa prices have hit a three-year high because of fear of El Niño hitting crops. Food prices are also reaching their highest on the index of Food Agriculture Organization (FAO). The UN body has attributed the price rise to fear of El Niño.
El Niño does affect global food production. According to a study published in Nature Communications in October 2013, El Niño affects 22 per cent to 24 per cent of harvested areas worldwide. But the prevailing fears mostly stem from the lack of understanding of the weather phenomenon.
The problem is scientists do not really understand El Niño and cannot predict when the weather phenomenon, which lasts from eight months to over a year, will strike and with what vigour. Such uncertainty leaves both farmers and governments undecided about their future course of action. For instance, the El Niño of 1997-98 has been the strongest since record keeping of the phenomenon began in 1950. Indian scientists and the authorities were dreading a bad monsoon that year. Though the eastern Pacific Ocean remained warm till February 1998, it did not affect Indian monsoon.
This year, till this magazine went to press, IMD, National Oceanic and Atmospheric Administration (NOAA) of the US and the Bureau of Meteorology of Australia had predicted 70 per cent chances of El Niño getting stronger during summer monsoon. NOAA had also predicted an 80 per cent chance of El Niño getting stronger towards the winters, while the European Centre for Medium-Range Weather Forecasts (ECMWF), an intergovernmental agency, put the chances at 90 per cent. Strength of El Niño also remained uncertain. “It could be large or small, or more likely moderate,” Tim Stockdale of ECMWF told Down To Earth.
Given the fallouts of El Niño, economical, social and political, weather agencies around the world have employed most advanced technologies like satellite observations and weather buoys and keep a paparazzi-like watch for the climate phenomenon. The US has even deployed ships in the El Niño formation area for real-time measurement of any anomaly in the sea surface temperature. “Yet we have hardly moved much since the British scientist Gilbert Walker provided the first clue of El Niño in early 1900s,” says Balaji Rajagopalan, professor of civil, environment and architectural engineering at the University of Colorado, US.
“We are monitoring sea surface warming of the El Niño region on a day to day basis,” says B P Yadav, director of IMD. “This helps us know the impact of El Niño on monsoon.”