MARY LOUISE KELLY, HOST:
Federal forecasters say the El Nino weather pattern is on its way out. This past year, it helped drive temperatures to new records. So what does that mean for this year? Lauren Sommer has more from NPR's climate desk.
LAUREN SOMMER, BYLINE: You can think of El Nino as a local thing with global impacts. It happens every few years when ocean temperatures in the Eastern Pacific get hotter than normal.
TOM DI LIBERTO: It may seem like how can that possibly affect where I live, thousands and thousands of miles away from the tropical Pacific Ocean?
SOMMER: Tom Di Liberto is a climate scientist at the National Oceanic and Atmospheric Administration. He says El Ninos can release a lot of heat from the ocean to the atmosphere. And so those years tend to be warmer, and 2023 definitely was.
DI LIBERTO: It wasn't surprising that 2023 was the warmest year on record. I think what was surprising was just how high temperatures got and how much they smashed the records by.
SOMMER: Those records fell because this El Nino came on top of climate change - the warming that comes from emissions from burning fossil fuels. The past eight years have been the hottest eight years ever recorded. With 2023 taking the top spot, climate scientists say it should be a warning for the future about the risks when El Nino and climate change mix.
Now, it looks like El Nino is heading for the exit, and the pattern will switch to a La Nina by the end of the summer. That can have a big impact on the weather, too, because it affects the jet stream, which steers weather across North America.
DI LIBERTO: And the jet stream really acts as, like, this storm highway. Storms like to hitch a ride on it. And if you change where that jet stream goes, you change where those storms go.
SOMMER: In La Nina years, the Southwestern U.S. tends to be drier, which can make droughts even worse. La Ninas can also lead to worse hurricane seasons in the Atlantic because they make it easier for storms to strengthen. So what about heat? Global temperatures tend to be cooler during a La Nina, but...
DI LIBERTO: Even while we shift into La Nina, we don't necessarily see the impacts of that on global temperatures until later in the year. I think the safest thing to say is that we should expect 2024 to be in probably the top five warmest years on record again, with a chance of it being top three, top two.
SOMMER: And because of climate change, maybe even No. 1.
Lauren Sommer, NPR News. Transcript provided by NPR, Copyright NPR.
NPR transcripts are created on a rush deadline by an NPR contractor. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of NPR’s programming is the audio record.
