Scientists change how El Nino is labeled to keep up with spike in temperature

El Nino warps weather worldwide

WASHINGTON -- The natural El Nino cycle, which warps weather worldwide, is both adding to and shaped by a warming world, meteorologists said.

A new study calculated that an unusual recent twist in the warming and cooling cycle that includes El Nino and its counterpart La Nina can help explain the scientific mystery of why Earth's already rising temperature spiked to a new level over the past three years.

Separately, scientists have had to update how they label El Nino and La Nina because of rapid weather changes cause by global warming. Increasingly hot waters globally have caused the U.S. National Oceanic and Atmospheric Administration this month to alter how it calculates when the weather pattern has flipped into a new cycle. It's likely to mean that more events will be considered La Nina and fewer qualify as an El Nino for warming tropical waters.

Earth's average monthly temperature took a noticeable jump up from the long-term upward trend connected to human-caused climate change in early 2023, and that increase continued through 2025. Scientists have many theories about what's happening, including an acceleration of greenhouse gas warming, a reduction in particle pollution from ships, an underwater volcano eruption and increased solar output.

In a new study in Nature Geoscience this month, Japanese researchers look at how the difference in energy coming to and leaving the planet — called Earth's energy imbalance — increased in 2022. An increased imbalance, or more trapped heat, then leads to warmer temperatures, scientists said. The researchers calculate that about three-quarters of the change in Earth's energy imbalance can be attributed to the combination of long-term human-caused climate change and a shift from a three-year cooling La Nina cycle to a warm El Nino one.