Australian Wildfires Indirectly Triggered Multi-Year La Nina Event, Study Finds


Researchers from the National Center for Atmospheric Research (NCAR) in the United States have discovered that the catastrophic Australian wildfires in 2019-2020 had far-reaching effects, including contributing to a multi-year La Nina event in the Tropical Pacific. The study, published in the journal Science Advances, reveals that the wildfires caused ocean cooling thousands of miles away, which ultimately led to the emergence of the rare La Nina phenomenon.

Lead author of the study, NCAR scientist John Fasullo, emphasized the long-lasting impact of the Australian fires, stating, “Many people quickly forgot about the Australian fires, especially as the COVID pandemic exploded, but the Earth system has a long memory, and the impacts of the fires lingered for years.” The emergence of La Nina is crucial for seasonal climate forecasts, as it can often be predicted months in advance.

What makes the recent run of La Ninas particularly noteworthy is that it is the only occurrence in the historical record that did not follow a strong El Nino. The streak began in the winter of 2020-21 and continued through last winter, making it the third consecutive string of La Ninas recorded since 1950.

To understand the climate impacts of the Australian wildfires, the researchers utilized the advanced NCAR-based computer model called the Community Earth System Model. They conducted simulations that incorporated the observed emissions from the wildfires, which encircled the Southern Hemisphere.

The study revealed that the aerosols formed from the wildfire emissions brightened the cloud decks across the Southern Hemisphere, especially off the coast of Peru. This resulted in cooling and drying of the air in the region, ultimately altering the convergence of the northern and southern trade winds. As a result, the Tropical Pacific Ocean experienced a cooling effect, leading to the formation of the multi-year La Nina event.

The findings of the research shed light on the missed forecast of the strong three-year La Nina event and underscore the importance of using coupled Earth system models, which integrate both the atmosphere and the ocean, for accurate climate forecasting.

The study highlights the interconnectedness of Earth’s systems and emphasizes the long-term consequences of natural disasters. It serves as a reminder that seemingly localized events can have far-reaching effects, influencing weather patterns and climate conditions across the globe. Understanding these complex interactions is crucial for improving our ability to predict and mitigate future climate events.


Please enter your comment!
Please enter your name here