To most of us, 9/11 is ancient history and dinosaurs still roamed the Earth when the US decided to teach Ho Chi Minh a lesson. But the Earth is 4.5 billion years old. On that basis, humans have been around for less than the blink of an eye, in geological terms. Researchers at the University of Arizona were intrigued by a news story that said in 2010 construction workers building the Panamerican Highway in Chile’s Altacama Desert had found a nearly perfectly preserved fossilized whale. Paleontologists rushed to the site to document the ancient treasure. While construction was halted, more fossil remains were unearthed. In quick succession, more than 40 specimens — whales, porpoises, and other marine mammals — were discovered, all of them having lived and died 6 to 9 million years ago. The place where they were found is known as Cerro Ballena, or “Whale Hill.” It is now recognized as the world’s largest concentration of whale fossils. A Rapid Change The paleontologists determined the animals perished quickly and in a relatively small area. The question was, why? Climate scientists supplied clues. They found that at approximately the same time as these animals were dying, there was a dramatic shift toward cooler sea surface temperatures. Geological records from that time, known as the late Miocene, reveal that this was a time of intense volcanic eruption caused by the tectonic upheaval that led to the building of the Andes mountains along the western edge of South America. Now, a study of the area has supplied an important piece of evidence that may unlock the secrets of the Cerro Balllena, or Whale Hill, in Chile. In a blog post by the University of Arizona, they report that vast amounts of volcanic ashes released into the atmosphere by volcanoes ended up in the ocean, particularly in the Southern Ocean. Volcanic ash is known to contain important nutrients, such as phosphorus, iron, and silicon. A significant increase in volcanic activity in the Andes occurred between eight and four million years ago, which would have delivered a significant pulse of nutrients — especially iron — to the Southern Ocean. A Diet Of Diatoms This induced a chain reaction driving environmental changes such as increased activity among primary producers like diatoms, which are some of the most abundant food sources in the oceans. They are single-celled algae that build intricate silicate shells. They create their own food and energy, usually from sunlight, and are the primary food source for some species of whales. Having access to an abundant new food source would have led to a significant increase in the size of those whales. But in places like Cerro Ballena, nutrients from Andes volcanoes may have had a more sinister result — widespread algal blooms that released toxins which were lethal to any whales in the affected areas. The same algal blooms also would have removed large amounts of carbon dioxide from the atmosphere, which would have helped produce even more algae. Less carbon dioxide in the atmosphere would have resulted in a drop in temperatures, with effects reaching far beyond South America. Smoke & Ash Volcanic eruptions have long been recognized as major sources of carbon dioxide in the atmosphere, before humans began burning fossil fuels on an industrial scale. But the role of volcanism in doing the opposite — actually cooling the Earth — has gone largely unrecognized, said Barbara Carrapa, a professor of geosciences at the University of Arizona College of Science and first author of this study, which was published in the journal Nature Communications Earth & Environment on April 13, 2026. “Once you put a lot of very important nutrients coming from volcanoes into the ocean, then your primary producers are going to go crazy, because all of a sudden they have a lot of nutrients available to them, and that, in turn, is going to affect the entire marine ecosystem,” Carrapa said. The study brought together experts in a variety of fields, including climate modeling, ocean geochemistry, geology, and paleobiology. Working together, they were able to demonstrate that Andean volcanoes may have provided the link between changes in ocean geochemistry and marine ecosystems that ultimately resulted in carbon sequestration and global cooling. The relationship between volcanic ash, and ultimately climate had been largely unexplored. Computer Modeling By combining paleoclimate records, fossil evidence, and geologic data with computer climate modeling simulations, the study shows a potential link between sustained, large-scale volcanism in the Altiplano-Puna Volcanic Complex in the Central Andes — the largest active silicic magma system on Earth — and global climatic and ecological change. The Miocene Epoch represented a major transition in both geography and climate, continuing a cooling trend that had begun 60 million years ago at the end of Mesozoic Era, which is also known as the “Age of the Dinosaurs.” By that time, the continents had taken their present day positions for the most part, only Antarctica was covered by ice, extensive forests were replaced by grasslands in many places of the world, and mammals were diversifying. Exploring the Miocene According to co-author Kaustubh Thirumalai, an associate professor in the University of Arizona Department of Geosciences, the Miocene was a time of profound change, establishing the ecosystems we see today. Giant mammals roamed the continents, including ground sloths, mammoths, and whales, which had set out as moderately sized creatures but embarked on an evolutionary trend toward the gigantic sizes they are known for. The cooling trend, particularly during the late Miocene, was accompanied by declining carbon dioxide levels in the atmosphere, but the exact cause was a mystery, Thirumalai said. Was the change caused by a decrease in volcanic activity releasing less carbon dioxide, or by an increase in chemical weathering, which takes carbon dioxide out of the atmosphere? To find answers, the team took advantage of climate simulation models to test various scenarios.. “To illustrate our approach, we’d say, ‘Let’s start erupting the Andes on purpose and see what happens,'” he said. “And what we found is that there is another component that wasn’t really appreciated — the biology of the ocean responds with feedback effects on climate worldwide.” Those feedback mechanisms can help store carbon in the deep ocean resulting in global cooling, Carrapa explained. A Beautiful Correlation “Once you take the biological effects of volcanoes fertilizing the ocean into consideration, we could see a beautiful correlation between Andean volcanism and all those changes that are happening in the ocean, specifically those looking at the late Miocene cooling event. Together with the Humboldt Current, which serves to distribute nutrients along the Pacific coast of South America, everything together created the perfect storm where, if you put the ash in the right place, and you ignite primary production, you eventually affect marine ecosystems as a whole, including whales.” “This work improves our understanding of how natural processes can regulate Earth’s climate, which is directly relevant to anticipating future climate change and its impacts on society,” said co-author and whale expert Mark Clementz, a professor of geology and geophysics at the University of Wyoming and co-author of this study. “By identifying links between volcanism, ocean productivity, and carbon dioxide drawdown, it provides insight into mechanisms that can influence global climate over long time scales.” The Carbon Cycle Is Non-Political The takeaway from this research is that carbon dioxide is key to life on Earth. Despite the woeful bleating of those who insist there is no such thing as too much carbon dioxide, the opposite is true. There can be too much and there can be too little. The Earth cares nothing for such vapid arguments. Unless the concentration of carbon dioxide is about where it was about 200 years ago, some species will die. The odds are high that humans will be one species that faces an existential challenge if the amount of carbon dioxide continues to increase. Call climate science the “green new scam” if you want; the Earth won’t care. It will still be here millions of years from now, but humans have less than a century to figure things out. There will be no do-overs or second chances. No amount of foot stomping, blustering, threatening, or dropping bombs on school children will alter the course of the Earth’s environment. If we fail to learn the lessons the Earth teaches us, we will pass from the scene just as did the whales in what is now the Atacama Desert.