El Nino: Six Questions And Answers

After the hottest global temperatures ever were recorded in June, the El Nino climate phenomenon could be set to make a return this European summer. DW has a closer look at this unique climate event.



El Nino could make a return this summer, according to predictions from the US Weather Service. German researchers even warn that it could become more frequent in the future too: making it the rule rather than the exception.



To help you understand more about this unique climate phenomenon, DW's environment team have answered six common questions about El Nino.



What exactly is El Nino?



El Nino is a climate anomaly in the South Pacific: in irregular intervals, the ordinary weather situation changes. The phenomenon occurs between Latin America's west coast and Southeast Asia, but its effects can be felt worldwide and it has often led to natural disasters.



Usually, warm sea surface water flows west from Latin America while cold water flows from the depths of the ocean to Latin America's coasts. In El Nino years those currents subside and sometimes change direction. The surface sea water off the coasts of Australia and Indonesia drop several degrees, whereas water temperatures in Latin America rise. The El Nino phenomenon last occurred in the years 2009 and 2010. Periods of El Nino usually last about a year.



What are the environmental impacts?



Corals, plankton and algae die in the warmer waters off Latin America's coast. Fish leave, searching for new waters due to a lack of food. This, in turn, impacts on Latin America's fishing industry.



The considerable warming of water also leads to low pressure areas off Latin America's west coast. This results in torrential rain, landslides, floods and storms. In the West Pacific – in Indonesia and northern Australia – it's the other way around: droughts, poor harvests and forest fires occur. During El Nino, the monsoon that usually brings the much-needed rain, either comes too late or doesn't come at all.



What are the causes?



Researchers still don't know exactly. But there are indications that El Nino is not man-made and instead has naturally-existed for centuries. But the greenhouse effect could be intensifying the El Nino phenomenon, so that it occurs more often or more intensely.



Where does the name El Nino come from?



The variations caused by El Nino tend to climax around the Christmas period. Peruvian fishermen, who were most affected by the climate phenomenon because of the lack of fish, dubbed it El Nino – meaning 'the boy' in Spanish, which in capital letters refers to baby Jesus.



What do the latest forecasts by US authorities mean?



The Climate Prediction Center (CPC) at the US Weather Service forecasts a 70 percent chance that El Nino will occur this northern hemisphere summer. There's an 80 percent probability that the climate phenomenon will occur this coming fall or winter. According to the CPC, however, El Nino is unlikely to be very intense. Experts are forecasting a weak to moderate intensity.



The CPC issues a monthly forecast for the ongoing year, based on sea surface temperatures registered in the concerned areas. Variations are identified at an early stage.



How permanent is the El Nino climate phenomenon?



Based on several well-established climate models, researchers from the Germany-based GEOMAR Helmholtz Center for Ocean Research have calculated that El Nino could become more common. By the year 2100, they say, typical air currents could weaken in general and shift eastwards as a result of global warming. That would lead to a permanent El Nino effect. But the researchers say it would have minimal effects.There is also conflicting evidence. In fact, data from 1979 to 2013 actually suggests that there has been an overall intensification of air circulation, which would work against the El Nino cycle. The gloomy prediction of a permanent El Nino effect is merely based on estimates.