Geo_lectures

Here’s a rather extraordinary discovery: humanity seems to have interrupted the beginning of the next ice age. We thought it might happen in the future, but the evidence suggests it's already happened. A new study in Science argues that the next major glaciation had already begun roughly 2,000 years ago, before modern warming reversed the trend in the 20th century. The evidence comes from the Barnes Ice Cap on Baffin Island, the last surviving remnant of the enormous Laurentide Ice Sheet that once covered much of Canada and reached as far south as Illinois. Because Barnes is frozen directly to its bedrock, advancing ice buries and preserves vegetation beneath it. Researchers radiocarbon dated plants emerging as the ice retreats to reconstruct its history. They found that after melting to a minimum extent around 3,000 years ago, the ice began expanding again about 2,000 years ago. The researchers interpret this as the earliest stage of the next glacial period. Left to natural orbital cycles, that cooling would have unfolded extremely slowly, potentially taking tens of thousands of years to rebuild a continent spanning ice sheet. But around 1960, the trend reversed. Summers became warm enough that Barnes began losing more ice than it gained, despite Northern Hemisphere summer sunlight continuing to slowly decline in a way that should favor renewed glaciation. Greenhouse warming had (thankfully) overwhelmed the natural cooling tendency. The Barnes ice cap may now disappear entirely within the next few centuries, removing the final remnant of an ice sheet that repeatedly served as the nucleus for much larger glaciations. There is a remarkable deep time perspective here. For millions of years, orbital cycles have pushed Earth between warmer interglacials and colder glacial periods. According to this study, that ancient cycle had started turning once again. Then, in the geological equivalent of an instant, humanity pushed hard enough in the opposite direction to stop it. Just so we're clear, this is a very very good thing. 📸 Geology Sciences Sources: 1) phys.org/news/2026-10-global… 2) science.org/doi/10.1126/scie…