Two Key Forces Behind Earth's Soaring Temperatures Revealed in New Study

A new study has revealed that around 75% of Earth's recent temperature rise comes from two key factors: long-term human-driven climate change and a shift from a cooling La Niña phase to a warming El Niño. The findings highlight how natural climate cycles interact with global warming to push temperatures higher.

The research also points to an unusually long La Niña period between 2020 and 2023, which played a role in increasing Earth's energy imbalance and contributing to warmer conditions.

The study breaks down the causes behind the recent spike in global temperatures. While greenhouse gas emissions remain the primary driver, the transition from La Niña's cooling effect to El Niño's warming influence has amplified the heat. This combination explains why recent years have seen record-breaking temperatures.

Meanwhile, the National Oceanic and Atmospheric Administration (NOAA) has updated its method for classifying El Niño and La Niña events. Since 2020, the agency has used a refined Oceanic Niño Index (ONI), incorporating better sea surface temperature data and statistical adjustments. This change has led to more frequent identification of weak El Niño or La Niña events, improving forecast accuracy.

The new approach has already shown results. For example, forecasts for Atlantic hurricane activity between 2021 and 2025 were adjusted downward due to the persistence of weak La Niña conditions. Post-season reviews confirmed that these revised predictions matched actual storm activity more closely than before.

Looking ahead, NOAA expects an El Niño to form later this year. While this could reduce Atlantic hurricane activity, it would also push global temperatures even higher by 2027. The agency's updated index, which compares tropical temperatures relative to the wider tropics, may also lead to more La Niña classifications in the future.

The study confirms that both human activity and natural climate cycles are driving recent temperature increases. With NOAA's refined El Niño and La Niña tracking, forecasts for hurricanes and global warming trends are becoming more precise.

An upcoming El Niño later this year could mean fewer Atlantic hurricanes but also warmer global conditions in the near future. The adjustments to NOAA's index aim to reflect these shifts more accurately as the climate continues to change.