Policy Responses to El Niño 1997-1998 : Implications for Forecast Value and the Future of Climate Services

El Niño 97-98 will be remembered as one of the strongest ever recorded (Glantz, 1999). For the first time, climate anomalies associated with the event were anticipated by scientists, and this information was communicated to the public and policy makers to prepare for the “meteorological mayhem that climatologists are predicting will beset the entire globe this winter. The source of coming chaos is El Niño . . .” (Brownlee and Tangley, 1997). Congress and government agencies reacted in varying ways, as illustrated by the headlines presented in Figure 7-1. The link between El Niño events and seasonal weather and climate anomalies across the globe are called teleconnections (Glantz and Tarlton, 1991). Typically, during an El Niño cycle hurricane frequencies in the Atlantic are depressed, the southeast United States receives more rain than usual (chapter 2), and parts of Australia, Africa, and South America experience drought. Global attention became focused on the El Niño phenomenon following the 1982-1983 event, which, at that time, had the greatest magnitude of any El Niño observed in more than a century. After El Niño 82-83, many seasonal anomalies that had occurred during its two years were attributed, rightly or wrongly, to its influence on the atmosphere. As a consequence of the event, societies around the world experienced both costs and benefits (Glantz et al., 1987). Another lasting consequence of the 1982-1983 event was an increase in research into the phenomenon. One result of this research in the late 1990s has been the production of forecasts of El Niño (and La Niña) events and the seasonal climate anomalies associated with them. This chapter discusses the use of climate forecasts by policy makers, drawing on experiences from El Niño 97-98, which replaced the 1982-1983 eventas the” climate event of the century.” The purpose of this chapter is to draw lessons from the use of El Niño -based climate forecasts during the 1997-1998 event in order to improve the future production, delivery, and use of climate predictions. This chapter focuses on examples of federal, state, and local responses in California, Florida, and Colorado to illustrate the lessons.

What Made El Niño 1997-1998 Famous?: The Key Events Associated with a Unique Climatic Event

El Niño 97-98 provided one of the most interesting and widely known climatic events of this century. It garnered enormous attention not only in the scientific community but also in the media and from the American public. El Niño developed rapidly in the tropical Pacific during May 1997, and by October “El Niño “had become a household phrase across America. Television and radio, newspapers and magazines pummeled America with the dire tales of El Niño during the fall of 1997 as the climate disruption battered the West Coast and the southern United States with storm after storm. Worried families changed vacation plans, and insurance executives pondered losses and raised rates. Victims of every type of severe weather blamed El Niño . After a winter filled with unusual weather, the head of the National Oceanic and Atmospheric Administration (NOAA) declared, “This winter’s El Niño ranks as one of the major climatic events of this century.” It was the first El Niño observed and forecast from start to finish. The event was noteworthy from several perspectives. • First, it became the largest and warmest El Niño to develop in the Pacific Ocean during the past 100 years. • Second, the news media gave great attention to the event, and El Niño received more attention at all levels than had any previous climate event. • Third, scientists were able to use El Niño conditions to successfully predict the climate conditions of the winter six months in advance. • Fourth, the predictive successes brought new credibility to the science of long-range prediction and, in general, acted to increase the public’s understanding of the climate and oceanic sciences. • Fifth, there were notable differences in how weather-sensitive decision makers reacted to the predictions, some used them for great gain, while others, fearing failure, did not. • Sixth, the great strength of El Niño brought forth claims that the phenomenon was the result of anthropogenic-induced global warming. This possibility was debated and added to the scientific-policy debates surrounding climate change. • Seventh, the net effect of the El Niño -influenced weather on the United States was an economic benefit, after early fears and predictions of great damages.

Summary

Much has been said about El Niño 97-98, some of it profound and some not. Several of the key findings from this assessment are reflected in an excellent short summary published by the World Meteorological Organization (WMO) in January 1999. . . . The 1997/1998 El Niño was probably the strongest in recorded history; it disrupted the lives of millions of people on all the Earth’s inhabited continents. Not all climate extremes and severe weather events of the period, however, can be directly attributed to the El Niño event. Further, not all its impacts were negative, and some regions that were expected to suffer were not seriously affected. (Obasi, 1999) . . . As the WMO found on a global scale, we have documented the profound impacts of El Niño 97-98 in the United States. But, perhaps contrary to conventional wisdom, the impacts in the United States were, in the aggregate, positive. Because El Niño shifted the geographical distribution of seasonal anomalies and because scientists were able to anticipate these shifts, many decision makers were able to profit from the early warnings to take compensatory actions. The accuracy of the predictions, and the successful use by decision makers of those predictions, offers the promise of the development of a more robust climate service in the United States. The remainder of this chapter summarizes the surprises, the lessons learned, and the legacy of El Niño 97-98. Once the rapid onset of El Niño conditions was detected late in the spring of 1997, forecasters successfully predicted the event’s strength and duration. The oceanic predictions reinforced the ensuing seasonal climate forecasts. The official seasonal outlooks issued by the National Oceanic and Atmospheric Administration (NOAA) in the summer of 1997 skillfully predicted the fall, winter, and early spring 1997-1998 conditions in many parts of the United States many months in advance. The seasonal forecasts had an accuracy of greater than 50 percent for temperatures and of between 30 percent and 50 percent for precipitation, the highest levels of accuracy ever attained, a reflection of the benefits of the considerable research and ocean-monitoring efforts directed at the El Niño Southern Oscillation (ENSO) over the past twenty years.

Who Used and Benefited from the El Niño Forecasts?

The long-range seasonal climate forecasts based on El Niño 97-98 conditions and issued from June through August 1997 for the fall, winter, and early spring conditions across the United States were accurate for many parts of the nation (see chapter 2). An important question concerns whether decision makers in weather-sensitive public and private organizations used these El Niño -derived seasonal forecasts. Most seasonal forecasters viewed with great confidence the predictions of a strong El Niño and associated precipitation, temperature, and storm anomalies expected across the United States. From their perspective, it was an opportune time to use and, presumably, to benefit from the forecasts. Our assessment of a large group of potential users of the seasonal forecasts sought to identify who used and did not use the forecasts, the reasons for their use or non use, and the applications and potential value of the forecasts derived from their use. Sector differences were assessed by sampling decision makers in agribusiness, water resources, utilities, and other sectors. Results of such use and non use investigations will help develop better, more effective strategies for disseminating climate forecasts (Pfaff et al, 1999). Another objective of this study was to understand the perceptions decision makers had of seasonal forecasts and how the successful predictions based on El Niño 97-98 may have modified those perceptions. Figure 5-1 presents a typical humorous media view of the forecasts. A survey of individuals was conducted to gather the desired information about how the seasonal forecasts based on El Niño 97-98 were obtained, evaluated, and incorporated into decisions. The study was designed to focus on decision makers in weather-sensitive positions and to employ sampling techniques tested and developed in prior surveys. These previous studies had developed, tested, and used questionnaires as the tool by which to gather information about the use of climate information by weather-sensitive users in water resources, agribusiness, and utilities (Changnon, 1982, 1991, 1992; Changnon and Changnon, 1990; Changnon etal, 1988, 1995; Sonka etal, 1992).

Was El Niño A Weather Metaphor—A Signal For Global Warming?

This chapter reviews media coverage of El Niño 97-98 and identifies some significant trends within that coverage. The coverage analyzed includes that provided by the major American television networks, the elite press, and significant regional newspapers. During the early months of the study period, news coverage of El Niño was focused on the science of the prediction and was framed as an issue of risk with appropriate uncertainty. However, as the predictions themselves were borne out in real-world phenomena, coverage of El Niño became event driven, and the phenomenon itself was treated as certainty. The risks of climate change attributed to El Niño outweighed the potential benefits in many media reports. Coverage of El Niño was extensive, particularly on the West Coast of the United States, where many individual weather events were connected with the larger phenomenon. The chapter then explores the possibility that the totality of the media coverage may have two lasting impacts. First, on the basis of existing scholarship on mass communication and risk communication, it is reasonable to suggest that the extensive news coverage of El Niño may have had some influence on public perception of climate change, particularly the salience of climate change in discrete regions of the nation. Second, the chapter suggests that the mediated reality of the 1997-1998 event will serve as a signal event for popular and political understanding of the consequences of global warming. Historically, journalism has been both hampered and helped by its definition of news. Previous studies of media coverage of a variety of “risky” events have noted that news accounts tend to be event focused, lack context, and treat science as a matter of dueling opinions, rather than a process of knowledge acquisition. These scholarly findings, which are long-standing, have had some impact on the professional community, particularly among science writers, who over the past two decades have become both better trained in science and more aware of the limitations of the concept of “news”—at least when it comes to reporting certain sorts of events. Media coverage of El Niño , in general, reflected these previously documented trends.

Impacts of El Niño’s Weather

The societal, economic, and environmental consequences of weather events and climate conditions in the United States vary across the nation as a result of hot and dry conditions in one region and cold and wet conditions in others, or storms in one area and none in others. Thus, for any given period, such as a season or year, the weather-caused impacts in the United States reveal a mix of winners and losers. This was certainly true with the impacts resulting from El Niño 97-98. The official National Oceanic and Atmospheric Administration (NOAA) predictions issued in June 1997 calling for more storms in parts of the nation and heavy precipitation for the South and Far West (Climate Prediction Center, August 13,1997) created major fears about large economic and social losses. The warnings of FEMA and the ensuing media hype created a nationwide perception that all “El Niño weather” was going to be damaging. This fear is illustrated in the cartoon in Figure 6-1. For example, the Financial Times (July 28, 1997) tied the strong El Niño 97-98 conditions to the huge U.S. losses due to El Niño 1982-1983, with 161 killed and losses of $2.2 billion. Such connections and citations resulted from the fact that the official El Niño predictions and Federal Emergency Management Agency (FEMA) warnings were comparing the large El Niño 97-98 to the large 1982-1983 event (CPC, July 1997; FEMA, August 12, 1997). California newspapers also focused on the 1982-1983 losses in that state, which included fourteen killed and $265 million in damages (San Francisco Chronicle, August 14, 1997; Sacramento Bee, October 15, 1997). This helped create considerable concern and launched major mitigation endeavors in California where storm and rain predictions were ominous. The resulting 1997- 1998 mitigative activities in California reduced losses and were a major beneficial impact of the use of the long-range predictions of the Climate Prediction Center (CPC) and the warnings issued by FEMA that promoted mitigation actions.

The Scientific Issues Associated with El Niño 1997-1998

The development of a record large El Niño event and its ensuing major effects on the nation’s weather over an eight-month period created a scientific event of major proportions. Key science-related questions that developed during El Niño 97-98 included: • Who was issuing El Niño -based climate predictions and for what conditions? • What kinds of weather conditions were caused by El Niño ? • What types of impacts were being projected as a result of the El Niño weather? • How accurate and useful were the El Niño -based climate predictions? • How accurate were the oceanic predictions relating to the development, intensification, and dissipation of El Niño 97-98? • Was the record-size event caused by global warming? Answers to such questions define the scientific information transmitted to the public, the scientific community, and decision makers during the event. This assessment focused on the scientific information that appeared during the period from May 1997 to June 1998, but it also included information that appeared a few months after El Niño ended (i.e., into early 1999), since these issuances reflect the thoughts and findings generated by scientists during the event. Topics assessed included: (1) the sources of the scientific information, (2) how the information was interpreted and by whom, (3) the accuracy of what was presented by different sources, and (4) the scientific issues that emerged, some of which involved disagreements and/or caused potential confusion for decision makers and the public. Most of the information assessed herein was extracted from the Internet, newspaper stories, and scientific documents published during the June 1997-June 1998 period. What scientific information relating to El Niño 97-98 was measured? We assessed the presentations of the physical descriptions of El Niño and ENSO and the predictions, the predictions based on El Niño conditions of future seasonal climate conditions as well as the resulting physical and societal impacts, the verifications of the seasonal climate predictions, and other, more general information about El Niño 97-98 that emerged, such as its magnitude in comparison to past El Niño events and its possible relationship to other conditions, such as global warming.

Causes, Predictions, and Outcomes of El Niño 1997-1998

One of the most prominent aspects of our weather and climate is its variability. This variability ranges over many time and space scales, from small-scale weather phenomena such as wind gusts, localized thunderstorms, and tornadoes, to larger-scale weather features such as fronts and storms and to prolonged climate features such as droughts, floods, and fluctuations occurring on multiseasonal, multiyear, and multidecade time scales. Some examples of these longer time-scale fluctuations include abnormally hot and dry summers, abnormally cold and snowy winters, a series of abnormally mild or exceptionally severe winters, and even a mild winter followed by a severe winter. In general, the longer time-scale variations are often associated with changes in the atmospheric circulation that encompass areas far larger than a particular affected region. At times, these persistent circulation features affect vast parts of the globe, resulting in abnormal temperature and precipitation patterns in many areas. During the past several decades, scientists have discovered that important aspects of interannual variability in global weather patterns are linked to a naturally occurring phenomenon known as the El Niño / Southern Oscillation (ENSO) cycle. The heart of ENSO lies in the tropical Pacific, where there is strong coupling between variations in ocean surface temperatures and the circulation of the overlying atmosphere. The terms El Niño and La Niña represent opposite extremes of the ENSO cycle, and they cause very different rainfall outcomes, as illustrated in Figure 2-1. Before describing the oceanic and atmospheric characteristics of the ENSO cycle, it is necessary to describe the average climatic conditions and how they vary throughout the year. Interannual climate variability is often measured by comparing the observed conditions to the long-term mean conditions. The mean state of the tropical Pacific Ocean is identified by both its surface and its subsurface characteristics, each of which exhibits considerable evolution across the eastern half of the tropical Pacific during the course of the year. Throughout the year, the ocean surface is warmest in the west and coldest in the east. The largest difference between the two regions is observed during September and October, when temperatures in the eastern Pacific reach their annual minimum.