An international team of Earth scientists, hydrologists, chemists, and physicists has uncovered compelling evidence that significantly reshapes our understanding of ancient volcanic activity and its global impact. Their research points to the Los Chocoyos supereruption, which occurred approximately 79,500 years ago in what is now the Atitlán volcanic system in Guatemala. By analyzing ice core samples from Greenland and Antarctica, the team revealed the global consequences of this eruption and provided new insights into how Earth responded to such catastrophic events. Their study, published in Communications Earth & Environment, challenges previous beliefs about volcanic supereruptions, particularly their potential to induce long-lasting ice ages.
The Los Chocoyos Supereruption: A Glimpse into Earth’s Past
The Los Chocoyos supereruption has long been recognized as one of the most massive volcanic events in Earth’s history. It is estimated that this eruption ejected an enormous volume of ash and volcanic gases into the atmosphere, creating a temporary cooling effect by blocking out the sun’s rays. Prior research suggested that such an event could have led to a full-scale ice age, drastically altering the planet’s climate and potentially threatening life as we know it. However, the findings from this new study complicate this narrative, showing that although the eruption was catastrophic, it did not trigger an ice age as once thought.
The Study: Ice Cores as Time Capsules
In order to better understand the aftermath of the eruption and its global effects, the research team focused on ice cores taken from Greenland and Antarctica, regions that act as natural time capsules for atmospheric conditions. Ice cores are incredibly valuable for scientists because they contain layers of frozen material that have accumulated over thousands of years, trapping tiny particles from volcanic eruptions, changes in temperature, and shifts in atmospheric composition. By studying these layers, researchers can determine the exact timing and scale of past events, and the impact they had on Earth’s climate.
Through their analysis, the team was able to pinpoint the 79,500-year-old volcanic ash deposits within the ice cores, correlating them with the timing of the Los Chocoyos eruption. The volcanic ash from the eruption had traveled far beyond Central America, reaching polar regions, where it was trapped in the ice. This provided solid evidence that the eruption had global ramifications, extending well beyond the immediate vicinity of the volcano.
Short-Term Climatic Effects: A Global Cooling Event
The team confirmed that the Los Chocoyos supereruption had a dramatic cooling effect on the planet. The massive quantity of ash released into the atmosphere would have blocked out a significant amount of sunlight, leading to a temporary drop in global temperatures. This phenomenon, often referred to as volcanic winter, likely caused widespread climatic disruptions across the globe. For a brief period, Earth experienced a sharp reduction in temperatures, and the loss of sunlight would have likely had detrimental effects on ecosystems and agriculture, resulting in a period of environmental stress.
However, what was truly surprising to the researchers was the speed at which the Earth recovered from this catastrophic event. Despite the massive cooling, the volcanic ash and gases that had caused the disruption were not persistent. Within just a few decades, the atmospheric conditions returned to pre-eruption levels. The ash cleared from the atmosphere, allowing sunlight to reach Earth once again, and temperatures gradually normalized. This was a crucial finding that contradicted the idea that a supereruption like Los Chocoyos could lead to an enduring ice age.
Rethinking the Ice Age Hypothesis
The finding that the Los Chocoyos supereruption did not trigger a prolonged ice age has important implications for our understanding of volcanic activity and its impact on global climate. Previously, some theories suggested that future volcanic supereruptions could have the potential to induce a new ice age, posing a serious existential threat to life on Earth, including humanity. This theory was largely based on the belief that volcanic eruptions of this magnitude could inject enough ash and sulfur into the atmosphere to block sunlight and cool the planet for centuries.
However, the evidence from the Los Chocoyos eruption challenges this view. The research suggests that while the eruption had significant short-term cooling effects, the Earth’s climate systems proved resilient. The planet was able to recover quickly from the eruption’s immediate effects, and a full-scale ice age did not materialize. This raises questions about the potential long-term impacts of future volcanic supereruptions and whether they would truly lead to catastrophic, ice age-like conditions.
Implications for Future Supereruptions
This groundbreaking research opens up new avenues for scientists to explore in their study of volcanic eruptions and their potential global consequences. The team is now focused on examining other supereruptions from Earth’s distant past to better understand how such events have shaped the planet’s climate over time. By comparing the impacts of different eruptions, they aim to build a more comprehensive understanding of volcanic activity and its relationship to Earth’s long-term climate patterns.
In particular, the research team is keen to explore whether there are other volcanic events that may have had even greater or more prolonged effects on the global climate than Los Chocoyos. This research could help improve predictions about how future supereruptions might affect Earth’s climate and whether there is a realistic danger of a new ice age or other extreme climatic shifts. Additionally, studying these ancient eruptions could provide valuable insights into the mechanisms that drive Earth’s climate recovery, helping scientists understand how quickly the planet can return to equilibrium after such catastrophic events.
Conclusion: A New Perspective on Volcanic Supereruptions
The findings from this international team of researchers significantly alter the way we view volcanic supereruptions and their global effects. While the Los Chocoyos supereruption was undoubtedly one of the most catastrophic events in Earth’s history, the research suggests that the planet was able to recover remarkably quickly, with no long-term shift into an ice age. This offers a more optimistic outlook regarding the potential impacts of future supereruptions, even though they would still pose serious risks to life on Earth.
As the team continues their research into past supereruptions, they aim to deepen our understanding of the complex interactions between volcanic activity and climate change, ultimately improving our ability to predict and prepare for potential future events. This study not only provides new insight into the ancient volcanic history of Earth but also serves as a reminder of the planet’s remarkable resilience in the face of catastrophic change. The research underscores the need for continued scientific inquiry into the mechanisms that govern Earth’s climate, as well as the importance of understanding the natural forces that have shaped our world for millions of years.
Reference: Helen M. Innes et al, Ice core evidence for the Los Chocoyos supereruption disputes millennial-scale climate impact, Communications Earth & Environment (2025). DOI: 10.1038/s43247-025-02095-6