El Niño events, marked by warming in the eastern equatorial Pacific, significantly impact global climate. This study shows that greenhouse warming is likely to double the frequency of extreme El Niño events. Extreme El Niño events are defined by a massive reorganization of atmospheric convection, leading to extreme rainfall in the usually dry eastern equatorial Pacific. The research uses climate models to show that the warming along the equatorial Pacific is faster than in off-equatorial regions, increasing the likelihood of atmospheric convection in the eastern equatorial Pacific. This results in more frequent extreme El Niño events, which can cause severe weather impacts globally, including floods, droughts, and extreme weather events. The study also highlights the importance of using process-based metrics, such as SST gradients and atmospheric convection reorganization, to accurately assess extreme El Niño events. The findings suggest that future climate change will lead to more frequent and severe weather events, with significant implications for the 21st century climate. The study uses data from climate models and historical observations to support these conclusions. The results are statistically significant and consistent across multiple models, indicating a strong likelihood of increased extreme El Niño events due to greenhouse warming.El Niño events, marked by warming in the eastern equatorial Pacific, significantly impact global climate. This study shows that greenhouse warming is likely to double the frequency of extreme El Niño events. Extreme El Niño events are defined by a massive reorganization of atmospheric convection, leading to extreme rainfall in the usually dry eastern equatorial Pacific. The research uses climate models to show that the warming along the equatorial Pacific is faster than in off-equatorial regions, increasing the likelihood of atmospheric convection in the eastern equatorial Pacific. This results in more frequent extreme El Niño events, which can cause severe weather impacts globally, including floods, droughts, and extreme weather events. The study also highlights the importance of using process-based metrics, such as SST gradients and atmospheric convection reorganization, to accurately assess extreme El Niño events. The findings suggest that future climate change will lead to more frequent and severe weather events, with significant implications for the 21st century climate. The study uses data from climate models and historical observations to support these conclusions. The results are statistically significant and consistent across multiple models, indicating a strong likelihood of increased extreme El Niño events due to greenhouse warming.