El Niño: Catastrophe or Opportunity

Abstract

El Niño–Southern Oscillation (ENSO) phenomenon, a periodic warming of sea surface temperatures in the eastern and central equatorial Pacific, generates a significant proportion of short-term climate variations globally, second only to the seasonal cycle. Global economic losses of tens of billions of dollars are attributed to extremes of ENSO (i.e., El Niño and La Niña), suggesting that these events disproportionately trigger socioeconomic disasters on the global scale. Since global El Niño/La Niña–associated climate impacts were first documented in the 1980s, the prevailing assumption has been that more severe and widespread climate anomalies, and, therefore, greater climate-related socioeconomic losses, should be expected during ENSO extremes. Contrary to expectations, climate anomalies associated with such losses are not greater overall during ENSO extremes than during neutral periods. However, during El Niño and La Niña events climate forecasts are shown to be more accurate. Stronger ENSO events lead to greater predictability of the climate and, potentially, the socioeconomic outcomes. Thus, the prudent use of climate forecasts could mitigate adverse impacts and lead instead to increased beneficial impacts, which could transform years of ENSO extremes into the least costly to life and property.