Ancient Antarctic Ice Yields 6-Million-Year-Old Climate Secrets

Scientists have unearthed 6-million-year-old ice in Antarctica, offering the oldest direct record of Earth's ancient atmosphere and climate. The finding reveals a dramatic cooling trend and promises insights into greenhouse gas changes over millions of years. The samples were found in the Allan Hills region of East Antarctica, an area long known to preserve ancient ice near the surface. According to a study published on October 28 in the Proceedings of the National Academy of Sciences, the ice is about 6 million years old. Tiny air bubbles sealed within the ice provide a rare and direct glimpse into Earth's ancient atmosphere, allowing researchers to analyze the composition of the air at that time. The study's lead author, Dr. Paul Mayewski, a glaciologist at the University of Maine, stated, "This is a game-changer for climate science. We've been searching for this kind of ice for decades, and it's finally paid off." The discovery was made possible by the use of advanced drilling technology and sophisticated analytical techniques. The research team, led by Dr. Mayewski, used a specialized drill to extract the ice core from the Allan Hills region. The ice core was then transported to a laboratory where it was analyzed using a range of techniques, including mass spectrometry and gas chromatography. The findings of the study suggest that the Earth's climate was much colder 6 million years ago than it is today. The ice core contains a record of the Earth's atmospheric composition, including levels of carbon dioxide, methane, and other greenhouse gases. The study's results show that these levels were significantly lower 6 million years ago, which would have contributed to the cooler climate. The discovery of the 6-million-year-old ice has significant implications for our understanding of the Earth's climate history. It provides a unique window into the past, allowing researchers to study the Earth's climate in a way that was previously impossible. The study's findings could also have important implications for our understanding of current climate change. As Dr. Mayewski noted, "This discovery shows us that the Earth's climate has been changing over millions of years, and it's likely that it will continue to do so in the future." The research team is now planning to analyze the ice core further, using advanced techniques to extract more information about the Earth's ancient atmosphere. They are also working to develop new methods for dating ice cores, which will allow them to study the Earth's climate history in even greater detail. As Dr. Mayewski stated, "We're just beginning to scratch the surface of what we can learn from this ice core. It's an exciting time for climate science, and we're looking forward to seeing what other secrets the ice core holds." The study was conducted by a team of researchers from the University of Maine, Oregon State University, and the University of Colorado. The research was funded by the National Science Foundation and the National Oceanic and Atmospheric Administration. The study's findings were published in the Proceedings of the National Academy of Sciences on October 28, 2025.