Transcript:
In the ancient coral reefs of the Galapagos, climate scientists have uncovered clues to how El Niño events are changing over time.
Cole: “El Niño is a natural phenomenon that every few years causes the tropical Pacific to become warmer than usual.”
Julia Cole of the University of Michigan says that this warming in turn affects weather around the world.
Over the past few decades, several El Niños have been very strong, and this year’s is the strongest on record.
But that official record is less than a century long.
So to learn how these El Niños compare with those in the more distant past, Cole studied coral skeletons – some more than 1,000 years old.
Cole: “Corals lay down annual bands similar to the rings of a tree.”
And analyzing the chemical composition of those bands reveals how warm the ocean water was each year.
Using this approach, Cole’s team concluded that El Niños have gotten more extreme since the industrial era when the widespread burning of fossil fuels began.
Cole: “These very strong events have gone beyond what we know now is a natural range for El Niño.”
So she says this indicates that human-caused climate change is making El Niños more intense.
Reporting credit: Sarah Kennedy / ChavoBart Digital Media
