Seven Things People Ought To Know About El Niño

Fragilecologies Archives
12 December 1997

Policy-makers, government agencies, scientists, social scientists, and the public are increasingly focusing on El Niño as one of the few bright spots in forecasting future states of the atmosphere and their impacts on societal activities. There will still be some failures (that is, misses) in forecasts of future El Niño events, but scientists are increasingly developing a more complete understanding of this important natural phenomenon. Combining this increased knowledge with an improved understanding of how El Niño can affect weather around the globe will surely enable governments and people to prepare for, as well as soften the impacts of, the adverse weather anomalies that have so far been reliably associated with El Niño events.

1. El Niño does not represent unusual behavior of the global climate.El Niño is usually described as a climate anomaly, or as an unusual or abnormal interaction between the air and the sea in the Pacific Ocean, that is not part of the normal climate system. In fact, El Niño is a normal part of the climate system and not apart from it. While we can talk about how the sea surface temperatures in the eastern and central Pacific Ocean may depart from some mathematical average condition, we must not view that departure as abnormal. El Niño (a warm event), like its counterpart La Niña (a cold event), is an integral part of the global climate system. Making this distinction more obvious and explicit can help people to realize that El Niño events have occurred for thousands of years and that they are to be expected and, hence, prepared for. Indeed, to go through a decade or two without an El Niño would be truly unusual.
2. El Niño is part of a cycle.El Niño gets all of the attention, not only from the media but from researchers as well. But, it is important to remember that El Niño is the warm phase of a cycle that also includes a cold phase, often referred to as La Niña. There has been less interest in La Niña over the past two decades because there have been fewer cold events than warm ones. However, there are also extreme weather events around the globe that have been associated with La Niña. Scientists say that La Niña-related extreme events are the opposite of those caused by or related to El Niño; for example, drought usually accompanies El Niño in Southern Africa, while flooding is associated with La Niña. However, researchers have yet to focus much of their attention on the cold part of the cycle.
3. Every weather anomaly throughout the world that occurs during an El Niño year is not caused by that El Niño.We must be careful concerning the adverse impacts on society and on ecosystems that we blame on an El Niño. There is a tendency to blame just about everything that happens during an El Niño event on that particular El Niño. This is just plain wrong. Only some parts of the globe are directly influenced by El Niño-spawned regional climate anomalies, and even those areas are not necessarily influenced in the same way by different El Niño events. Every year, even in non-El Niño years, extreme record-setting weather events are occurring at various locations around the globe. The linkages between El Niño and regional climate anomalies have been identified through:
   1. observations of direct linkages between warm surface water in the equatorial Pacific and distant regional anomalies (such as drought in New Guinea or Australia);
   2. statistical measures identifying probable linkages; and
   3. wishful thinking, whereby people think that a particularly disruptive event was due to El Niño.
4. El Niño has a positive side as well.For example, during an El Niño the number of hurricanes along the Atlantic and Gulf coasts are greatly reduced in number. During the 1997 El Niño year we did not have a devastating blockbuster hurricane. In fact, it was an unusually quiet hurricane season. As another example, during an El Niño year there is a sharp increase off the coast of Ecuador in the amount of wild shrimp larvae, which is good for that country’s shrimp industry. Very little research has focused on compiling the instances where societies have benefitted from El Nino’s appearance.
5. There will continue to be surprises associated with future El Niño events.Scientists have really only focused on El Niño as a Pacific basin-wide phenomenon since the mid to late 1970s. We have not yet witnessed all of the ways they can form, nor have we witnessed all of the ways that they can affect societies and ecosystems. Thus, each succeeding El Niño will likely surprise scientists as well as the public in the timing or frequency of its onset or in the magnitude (level of destruction) of its impacts.
6. The impact of global warming on El Niño is not as yet known, speculation notwithstanding.Despite the increasing speculation about the possible ways that global warming of the atmosphere could affect El Niño events (timing, frequency, magnitude), the scientific community is unable at this time to say with any degree of reliability or confidence what the impacts of a global warming will be on El Niño.
7. Forecasting El Niño is different than forecasting the impacts of El Niño.Scientists are trying to forecast El Niño by focusing their research efforts on identifying those characteristics of El Niño that appear early in its development. The success (or failure) to forecast El Niño several months in advance of its onset is different from forecasting the impacts of that particular El Niño. Forecasting impacts on societies around the globe requires different research methods. Each El Niño seems to cause a different set of impacts (such as droughts, floods, fires). However, some impacts tend to happen during most El Niño events. Problems in forecasting El Niño (the event), therefore, are different from those related to forecasting El Niño’s impacts.