UN Secretary-General Antonio Guterres says the world must treat the El Niño update as the urgent climate warning it is. (File Photo)The World Meteorological Organization (WMO), an agency of the United Nations, warned on Tuesday that the impending El Niño will increase the risk of extreme weather over the coming months.In an update titled Prepare for El Niño, the WMO said the certainty of El Niño development—an ocean-atmosphere phenomenon where surface water along the equatorial and central Pacific Ocean remains warmer than usual—during June-August was now 80 per cent. The phenomenon will influence global temperature and rainfall.An El Niño event can last from a few months to up to two years and usually peaks during the winter months.Like forests, oceans are great heat sinks. But when the heating is excessive, it does more harm than good. One of the primary drivers, the WMO said, for this warming trend was the feeding of unusually warm subsurface conditions across the tropical Pacific Ocean.“The temperatures exceeding 6 degrees Celsius above average were providing a substantial reservoir of heat, which is resulting in the observed surface warming,” the WMO said.In his message to the world on the developing El Niño and its possible impacts, UN Secretary-General Antonio Guterres said, “El Niño is arriving on our doorstep in the coming months with 90% certainty. The world must treat it as the urgent climate warning it is. El Niño conditions will pour fuel on the fire of a warming world.”The phase of ENSO (El Niño-Southern Oscillation), which describes the interaction between ocean temperatures and atmospheric pressure in the tropical Pacific Ocean, is determined by the value of the Relative Oceanic Niño Index. This index is the sea surface temperature departure value from normal, measured over the Niño 3.4 region (5ºN-5ºS, 120º-170ºW) along the equatorial Pacific Ocean. When this value is 0 degrees Celsius, it is ENSO neutral. Warmer temperatures and a value above +0.5 degrees correspond to El Niño conditions, whereas cooler sea surface temperatures below -0.5 degrees Celsius mean La Niña.Story continues below this adThe latest index value for February-April is -0.5 degrees Celsius. The sea surface temperatures measured during late April to mid-May showed a rising trend, confirming that the El Niño thresholds were approaching, the WMO said.