GENEVA, Switzerland - The UN weather agency Tuesday, April 15 warned there was a good chance of an "El Niño" climate phenomenon in the Pacific Ocean this year, bringing droughts and heavy rainfall to the rest of the world.
The World Meteorological Organization (WMO) said its modeling suggested a "fairly large potential for an El Niño, most likely by the end of the second quarter of 2014."
"If an El Niño event develops...it will influence temperatures and precipitation and contribute to droughts or heavy rainfall in different regions of the world," WMO chief Michel Jarraud said in a statement.
The El Niño phenomenon occurs every two to 7 years, when the prevailing trade winds that circulate surface water in the tropical Pacific start to weaken.
WMO pointed out Tuesday that since February, trade winds had weakened and there had been a significant warming of the waters below the surface in the central Pacific.
"While there is no guarantee this situation will lead to an El Nino event, the longer the trade winds remain weakened, and sub-surface temperatures stay significantly warmer than average, the higher the likelihood," it said.
Two-thirds of climate models predicted that the phenomenon would begin sometime between June and August, with a few suggesting it could start as early as May, and the remainder predicting no El Niño this year, it said.
The last El Niño occurred between June 2009 and May 2010.
It is often followed by a return swing of the pendulum with La Niña, which is characterized by unusually cool ocean surface temperatures in the central and eastern tropical Pacific.
Scientists, who closely monitor the two climate patterns, say that while they are not caused by climate change, rising ocean temperatures caused by global warming may affect their intensity and frequency.
"El Niño has an important warming effect on global average temperatures," Jarraud cautioned, stressing that combined with human-induced warming from greenhouse gases such events had "the potential to cause a dramatic rise in global mean temperature." - Rappler.com