Ancient plankton suggests extreme El Niños will become twice as common

A reconstruction of Pacific Ocean temperatures 21,000 years ago, based on the chemistry of tiny shells, adds hefty support to projections that climate change will make strong El Niño events far more common, leading to more extreme weather around the world.

“We’re projecting a pretty dramatic change,” says Kaustubh Thirumalai at the University of Arizona.

The irregular cycle between warmer- and cooler-than-average temperatures in the equatorial Pacific Ocean –…