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Extreme El Niño Frequency Increase

El Niño is in the process of becoming more intense due to climate change. In a warmer world there is more heat being trapped every year, so there is more heat in the oceans to fuel El Niño events. Scientists caution, however, that this is still an active area of research, and the risks associated with El Niño due to climate change remain uncertain.

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Climate science at a glance

  • El Niño events are becoming more intense.
  • In a warmer world there is more heat being trapped every year, so there is more energy for El Niño events to work with.
  • A 2019 detection study found that climate change is reshaping the evolution and intensity of El Niño events in a way that favors the occurrence of more “super” El Niños.[1]

Background information

What is El Niño?

El Niño is a periodic warming of ocean waters along with shifts in trade winds and precipitation patterns in the equatorial tropical Pacific Ocean. By adding tremendous amounts of heat to the ocean’s surface and the atmosphere, El Niño events can alter weather patterns worldwide. This is especially true for the United States during the winter, when California can be pounded by a relentless series of storms.

What is the El Niño Southern Oscillation?

El Niño is one of two phases of the El Niño Southern Oscillation (ENSO), a recurring global circulation pattern involving energy exchanges between the tropical Pacific Ocean and atmosphere. ENSO consists of oscillations between a warm phase (El Niño) and a cool phase (La Niña). Each phase typically lasts from nine months to a year, and occurs every three to seven years.


El Niño trends and climate change

  • Models show that under global warming, even if the ENSO's sea surface temperature remains unchanged, humidity increases, primarily due to the Clausius–Clapeyron relationship.[2]
  • Scientists studying coral growth rings found that El Niño events of the past few decades are more variable and more intense than the norm established over the past 7,000 years.[3] While the study did not establish a causal link between climate change and intensifying El Niño events, the trend makes sense under the framework suggesting that El Niño discharges heat absorbed during neutral years.
  • Increased atmospheric moisture content may also affect El Niño by intensifying regional precipitation variability, leading to periods of more extreme flooding or drought.[4]
  • A 2013 study finds human-induced global warming will double the number of extreme ENSO events, raising concern that disruptions from El Niño will worsen in a warmer world.[5]

Studies attribute intensifying El Niño events to climate change

  • (Wang et al. 2019): Climate change is reshaping the evolution and intensity of El Niño events in a way that favors the occurrence of more “super” El Niños.[1]

Select a pillar to filter signals

Air Mass Temperature Increase
Arctic Amplification
Extreme Heat and Heat Waves
Glacier and Ice Sheet Melt
Global Warming
Greenhouse Gas Emissions
Land Ice and Snow Cover Decline
Land Surface Temperature Increase
Permafrost Thaw
Precipitation Falls as Rain Instead of Snow
Sea Ice Decline
Sea Surface Temperature Increase
Season Creep/ Phenology Change
Snowpack Decline
Snowpack Melting Earlier and/or Faster
Atmospheric Moisture Increase
Extreme Precipitation Increase
Runoff and Flood Risk Increase
Total Precipitation Increase
Atmospheric Blocking Increase
Atmospheric River Change
Extreme El Niño Frequency Increase
Gulf Stream System Weakening
Hadley Cell Expansion
Large Scale Global Circulation Change/ Dynamical Changes
North Atlantic Surface Temperature Decrease
Ocean Acidification Increase
Southwestern US Precipitation Decrease
Surface Ozone Change
Surface Wind Speed Change
Drought Risk Increase
Land Surface Drying Increase
Intense Atlantic Hurricane Frequency Increase
Intense Cyclone, Hurricane, Typhoon Frequency Increase
Intense Northwest Pacific Typhoon Frequency Increase
Tropical Cyclone Steering Change
Wildfire Risk Increase
Coastal Flooding Increase
Sea Level Rise
Air Mass Temperature Increase
Storm Surge Increase
Thermal Expansion of the Ocean
Winter Storm Risk Increase
Coral Bleaching Increase
Habitat Shift or Decline
Parasite, Bacteria and Virus Population Increase
Pine Beetle Outbreaks
Heat-Related Illness Increase
Infectious Gastrointestinal Disease Risk Increase
Respiratory Disease Risk Increase
Vector-Borne Disease Risk Increase
Storm Intensity Increase
Tornado Risk Increase
Wind Damage Risk Increase
What are Climate Signals?