South American scientists are still quibbling over whether an El Niño event is building. The uncertainty is impacting officials and states, who must act soon to prevent the worst scenarios, including deaths from natural disasters, meteorological organisations say.
Eduardo Zambrano, a researcher at the International Research Centre on El Niño Phenomenon, in Ecuador, one of the World Meteorological Organization’s regional climate centres, says the problem is that the phenomenon’s effects have yet to become clear across the whole continent.
“Some satellite images show us a very hot Pacific Ocean, one of the El Niño characteristics.”
Willian Alva León, Peru’s Meteorological Society
“Nevertheless, we can tell that it is extremely dry in the northeast of Brazil, in Venezuela and the Caribbean,” he says, adding that there has also been unusually heavy rainfall in the Atacama Desert in Chile since March, and floods in Argentina, Paraguay and Uruguay.
El Niño reaches its peak as a mass of warm water in the eastern Pacific Ocean. This plays havoc with the weather over Central and South America, causing arid, high-altitude regions to become rainy, while creating droughts over the lowlands and storms in the Caribbean.
But El Niño remains difficult to predict due to its many different impacts. Scientists, Zambrano points out, were expecting an El Niño last year and “all alarms were sounded, but then nothing big happened because of changes in the wind direction”.
This failure means many organisations are careful to avoid being seen to be scaremongering. “Some satellite images show us a very hot Pacific Ocean, one of the El Niño characteristics,” says Willian Alva León, the president of Peru’s Meteorological Society. But, he adds, this heat is not moving south-east towards the Peruvian coast as it would during an El Niño event.
León says that he thinks the main heat build-up for El Niño has already happened, meaning the phenomenon might be cooling off. “El Niño has an energy limit and I think it has been already reached,” he says.
The disagreement between different weather research institutions worries policymakers, who need clear guidance to begin preparations. Ciro Ugarte, director of the Pan American Health Organization’s emergency preparedness and disaster relief department, says acting on El Niño predictions is mandatory to ensure the continent can cope with the fallout.
“Being prepared is important because it decreases the impact of the phenomenon and reduces endemic illness,” he says. To assess the likelihood of El Niño, some scientists are using modelling. María Teresa Martínez, vice-director of meteorology at Colombia’s Institute of Hydrology, Meteorology and Environmental Studies, says reliable models predicted in March that there was a 60 per cent chance of an El Niño event. “Now El Niño is developing strongly from its forming stage to grown stage, which will be reached in December,” she says.
Ugarte admits there is no certainty, but says that, for his organisation, “doing nothing is not an option”.
“As policymakers, our best choice is dealing with consensus among scientists, and now the consensus is that there is a 95 per cent chance of having a strong or very strong El Niño year,” he says.