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It’s Official: Earth’s Next Ice Age is on the Horizon A major study published in Science (2025) by researchers at Cardiff University has pinpointed the orbital mechanics that drive the timing of Earth’s ice ages. By examining deep-sea sediment cores containing microscopic fossil shells, the team reconstructed climate patterns going back over 1 million years. Their findings reveal a clear pattern: The end of an ice age happens when two factors align axial tilt (obliquity), which changes how much sunlight reaches high latitudes, and precession, the slow wobble in Earth’s spin axis that shifts the timing of the seasons. The start of an ice age appears to be triggered mainly by a gradual decrease in axial tilt, which reduces summer sunlight at the poles and allows ice to build year after year. This pattern explains the roughly 100,000-year cycle of ice ages seen throughout the Pleistocene epoch. Based on these cycles, the next natural glaciation would begin in about 11,000 years — if human influence weren’t a factor. However, other studies, including NASA climate modeling and research by the Potsdam Institute for Climate Impact Research, suggest that high greenhouse gas concentrations could postpone the next ice age by tens of thousands of years. Some projections indicate that CO₂ levels above 300 ppm can disrupt the natural trigger entirely and we are already at over 420 ppm today.