Glaciers have been present somewhere on Earth for at least 60 million years, a period stretching back almost to the time of the dinosaurs. That’s the key finding of our new research, which pushes the date when the planet was last glacier-free back by at least 26 million years.
It may not feel like it due to profound recent warming, but Earth is currently in an “icehouse phase” – at least, relative to its long-term geological history. Even after a century of global warming and many glaciers shrinking or disappearing, conditions are still cold enough to support permanent ice sheets at both poles and more than 200,000 glaciers at high and low elevations and latitudes across the planet. This has not always been the case.
