El Niño, a climate troublemaker, has long been one of the largest drivers of variability in the global climate. Every few years, the tropical eastern Pacific Ocean seesaws between warm (El Niño) and cold (La Niña) phases. This reshuffles rainfall patterns, unleashing floods, droughts and storms thousands of miles from the Pacific origin.
The 1997-98 and 2015-16 El Niño events, for instance, brought catastrophic flooding to the eastern Pacific while plunging Africa, Australia and southeast Asia into severe droughts.
These disruptions don’t just alter weather, but devastate crops, collapse fisheries, bleach coral reefs, fuel wildfires, and threaten human health. The 1997-98 El Niño alone caused an estimated US$5.7 trillion (£4.4 trillion) in global income losses.
