Next El Niño could be tipping point for a hotter climate

In 2015, heat from the tropical Pacific helped raise the global annual average temperature irreversibly past 1 degree Celsius above the pre-industrial baseline. And in 2024, Earth experienced the hottest year recorded in human history, aided by another El Niño boost. Even a moderately strong El Niño during the next 12 to 18 months could drive the average global temperature to about 1.7 degrees Celsius above the preindustrial level, climate scientist James Hansen told Inside Climate News. Hansen doubts the world will meaningfully cool back down to below the 1.5 degree Celsius mark after the El Niño fades. The study’s definition of a super El Niño is when the sea surface temperature anomaly in the tropical Pacific “exceeds 2 standard deviations above normal”—not an ordinary fluctuation, but more of a systemic warning sign. The impacts are clustered in areas known to be sensitive to long-distance climate connections and regions “that are already prone to climate regime shifts,” wrote Kug, a climate researcher at Seoul National University in South Korea. There are only three super El Niños on record: in 1982-83, 1997-98, and 2015-16. All of them contributed to regime shifts in regional ocean temperatures, leading to unprecedented marine heat waves that destroyed or damaged coral reefs and caused mass die-offs and starvation among many marine organisms, from starfish to seabirds and marine mammals. Those impacts, as well as changes in drought and extreme heat over land areas, persisted for years and could shift some regional patterns for decades, according to the study. Kug said the main “regime-shift hotspots” in oceans include the central North Pacific, the southeastern Indian Ocean, the southwestern Pacific, and the Gulf of Mexico, areas where globally linked atmospheric connections “can strongly perturb the ocean surface and, in some cases, help anomalies persist.” Kug said the study identified super El Niño regime shifts in East Africa and the Maritime Continent—the island-rich region between the Indian and Pacific Oceans around Indonesia, Malaysia, and Papua New Guinea. The research also uncovered strong El Niño signals in the form of soil moisture changes in central southern Asia, central Australia, the Amazon, and western Greenland. The land responses are “linked to the way super El Niño reshapes regional precipitation and temperature through teleconnections,” he said in an email. “These shifts matter because they can turn a short-lived climate shock into a longer-lasting risk,” he wrote. If soil moisture stays below normal for several years, crops are exposed to repeated heat and water stress across multiple growing seasons with “direct consequences for food production and water security.” The potential for more destructive physical impacts raises deeper concerns about how societies that developed under relatively stable climate conditions will function in a world with shifting baselines and sharper swings between droughts and floods, more intense tropical storms, expanded fire seasons and long-lasting unseasonal extreme heat. Understanding how stronger El Niños reshape the climate can help countries close what the United Nations calls the global adaptation gap, which is the widening distance between known climate risks and actual preparation.